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Gear / Technical Help => Battery Boxes, Preamps, Mixers, ADCs, and Processors => Topic started by: spyder9 on June 30, 2009, 09:57:00 PM

Title: Aerco MP-2 preamp - Part 2
Post by: spyder9 on June 30, 2009, 09:57:00 PM
Thread #1 is here:

http://taperssection.com/index.php/topic,56579.msg1649844.html#msg1649844
Title: Re: Aerco MP-2 preamp - Part 2
Post by: prof_peabody on June 30, 2009, 10:15:23 PM
.
Title: Re: Aerco MP-2 preamp - Part 2
Post by: dactylus on July 01, 2009, 07:16:31 AM

Checking in, possibly purchasing in 2010...

 ;)
Title: Re: Aerco MP-2 preamp - Part 2
Post by: prof_peabody on July 01, 2009, 01:41:37 PM

Checking in, possibly purchasing in 2010...

 ;)

Now would be a good time to order.  I think Jerry still works for a school, so he has a lot more time in the summer to work on the pre-amps.
Title: Re: Aerco MP-2 preamp - Part 2
Post by: manitouman on July 01, 2009, 01:55:50 PM
Really loving how the DPA 4023>Aerco>MTII is sounding. Compact and easy to set up.
Title: Re: Aerco MP-2 preamp - Part 2
Post by: dactylus on July 01, 2009, 06:50:26 PM

Checking in, possibly purchasing in 2010...

 ;)

Now would be a good time to order.  I think Jerry still works for a school, so he has a lot more time in the summer to work on the pre-amps.

I know where you're coming from, I just purchased another pre and I need to wait until my wife lets me spend again...

 ;D
Title: Re: Aerco MP-2 preamp - Part 2
Post by: nottingham on July 01, 2009, 07:14:40 PM
Quote
I know where you're coming from, I just purchased another pre and I need to wait until my wife lets me spend again...
:angry2:
Title: Re: Aerco MP-2 preamp - Part 2
Post by: stevetoney on July 01, 2009, 10:13:15 PM

Checking in, possibly purchasing in 2010...

 ;)

Now would be a good time to order.  I think Jerry still works for a school, so he has a lot more time in the summer to work on the pre-amps.
I know where you're coming from, I just purchased another pre and I need to wait until my wife lets me spend again...

 ;D


Just withhold sex until she says 'uncle'.  No wait...that's what they do to us, not vice versa.  DAMMIT!

Title: Re: Aerco MP-2 preamp - Part 2
Post by: nottingham on July 01, 2009, 10:44:08 PM
Steve, you go boy!!!
Title: Re: Aerco MP-2 preamp - Part 2
Post by: dmonkey on July 01, 2009, 11:07:45 PM
checking in.

Digging my unit. Still figuring out how to power it and such. Ran out of batteries the other night at a long gig. Discovered that the same cable I use for my R44 works with this unit too. Gotta go buy a new Rat Shack cable.
Title: Re: Aerco MP-2 preamp - Part 2
Post by: stevetoney on July 02, 2009, 09:21:01 AM
checking in.

Digging my unit. Still figuring out how to power it and such. Ran out of batteries the other night at a long gig. Discovered that the same cable I use for my R44 works with this unit too. Gotta go buy a new Rat Shack cable.

Just pick up one or two DVD batteries (commonly called Wally World's around here) or a Techeon and you're set for mega hours.  The higher capacity Techeon (I think $89) would probably power the Aerco for a couple of days...seriously.
Title: Re: Aerco MP-2 preamp - Part 2
Post by: spyder9 on July 03, 2009, 10:13:07 AM
I ran the Aerco w/ the Tekkeon running at 12v.  No problems what-so-ever.  Only dropped 2 bars after recording 10 hours of music at a festie.  Enough juice left to go the next day for another 10 hours. 
Title: Re: Aerco MP-2 preamp - Part 2
Post by: manitouman on July 03, 2009, 04:21:45 PM
What Tekkeon? I've been using the wally world batteries and they power pretty good. Never did a long recording to see how long I can go on it.
Title: Re: Aerco MP-2 preamp - Part 2
Post by: spyder9 on July 03, 2009, 07:42:17 PM
I have a Tekkeon MP3400.  Grabbed from eBay.  They are not cheap as a Wally bat.  Run ya about $100.00.  Worth it for me, for my Nak 1K's get prickly when the voltage drops below 9V.
Title: Re: Aerco MP-2 preamp - Part 2
Post by: willndmb on July 03, 2009, 08:44:36 PM
I have a Tekkeon MP3400.  Grabbed from eBay.  They are not cheap as a Wally bat.  Run ya about $100.00.  Worth it for me, for my Nak 1K's get prickly when the voltage drops below 9V.
he could prob get away with a 9v dvd battery though don't you think?
the 9v dvd is well tested with a ua5 and akg
Title: Re: Aerco MP-2 preamp - Part 2
Post by: manitouman on July 03, 2009, 08:58:31 PM
I have a Tekkeon MP3400.  Grabbed from eBay.  They are not cheap as a Wally bat.  Run ya about $100.00.  Worth it for me, for my Nak 1K's get prickly when the voltage drops below 9V.
he could prob get away with a 9v dvd battery though don't you think?
the 9v dvd is well tested with a ua5 and akg

That's exactly what I'm using. The same kind of battery I use for the V3. It just takes a different type of connector. I've been running both AKG 48X and DPA 4023's in front of the Aerco. If something happened to the recording by not enough juice to the mics, I'll know in the next few days while I work on them. From what I've heard, nothing happened to quality. I'll post later with results, good or bad.

For what it's worth, this little box is awesome!  ;D

EDIT: Everything is good! Like I said, this little box rocks! Very happy with the results of my recordings from the past three shows.
Title: Re: Aerco MP-2 preamp - Part 2
Post by: spyder9 on July 04, 2009, 11:39:36 AM
I have a Tekkeon MP3400.  Grabbed from eBay.  They are not cheap as a Wally bat.  Run ya about $100.00.  Worth it for me, for my Nak 1K's get prickly when the voltage drops below 9V.
he could prob get away with a 9v dvd battery though don't you think?
the 9v dvd is well tested with a ua5 and akg

My Naks will drop 6 db in one channel if the voltage slips below 9v.  I've used the Walmart and the 9.6 NMH batteries, but to no avail.  Since the Aerco can accept up to 18v, the Tekkeon gets the job done.  Tekkeon goes all the way up to 19v.  Clean.  No issues.   
Title: Re: Aerco MP-2 preamp - Part 2
Post by: manitouman on July 04, 2009, 11:44:57 AM
^^^That's good to know. I may have to switch it up just to be on the safe side. I'd rather be safe than sorry. I wouldn't want anything to happen right at the critical moment with the headliner. Thanks for the info!  ;D
Title: Re: Aerco MP-2 preamp - Part 2
Post by: stevetoney on July 05, 2009, 12:40:58 AM
I wouldn't want anything to happen right at the critical moment with the headliner. Thanks for the info!  ;D

^^ That's why I love the Tekkeon.  In my case, I have the high capacity power runner, which is the father or grandfather of the Tekkeon.  Anyway, with the Tekkeon, you have ample capacity and variable voltage available to you.  Yes, they're expensive but everyone knows that having peace of mind in the field with regards to power is worth it's weight in gold.  (since we've all had shows where remote power problems kicked out butts.)  So, DVD batteries are usually good, but that Tekkeon is great! 
Title: Re: Aerco MP-2 preamp - Part 2
Post by: manitouman on July 05, 2009, 09:03:58 PM
I can't find a 3400, here's a MP3450. Would that work?

http://www.amazon.com/Tekkeon-MP3450-myPower-Rechargeable-Battery/dp/B000S9JWJI/ref=sr_1_1?ie=UTF8&s=electronics&qid=1246842100&sr=8-1

Because there's also a MP3450i. Not sure which is which or how they are different.
Title: Re: Aerco MP-2 preamp - Part 2
Post by: dennisrtyler on July 05, 2009, 09:20:44 PM
I can't find a 3400, here's a MP3450. Would that work?

http://www.amazon.com/Tekkeon-MP3450-myPower-Rechargeable-Battery/dp/B000S9JWJI/ref=sr_1_1?ie=UTF8&s=electronics&qid=1246842100&sr=8-1

Because there's also a MP3450i. Not sure which is which or how they are different.
here's the spec sheet for their different models. i had 2 of the 3300s back when i had my P2 and they rock.
http://www.tekkeon.com/products-mypall-specs.html (http://www.tekkeon.com/products-mypall-specs.html)
Title: Re: Aerco MP-2 preamp - Part 2
Post by: stevetoney on July 05, 2009, 09:26:17 PM
I can't find a 3400, here's a MP3450. Would that work?

http://www.amazon.com/Tekkeon-MP3450-myPower-Rechargeable-Battery/dp/B000S9JWJI/ref=sr_1_1?ie=UTF8&s=electronics&qid=1246842100&sr=8-1

Because there's also a MP3450i. Not sure which is which or how they are different.
It looks to me like that's exactly what you'd want.  The only thing to question is whether the proper tip is included and if it's not whether the standard Radio Shack tips are compaible.  FWIW, the cable I have with my Power Runner is compatible with the RS tips, so I'm gonna say that I think that the answer is 'yes' to that question, although I can't say whether one of the nine tips packaged with the 3450 is one that would fit with the Aerco.  

Finally, in reading through the Amazon link, I'm in agreement that I can't really see the obvious difference between the 3450 and 3450i...it looks to me like the 3450 would work fine for you and I know it would last for mega-hours.

I absolutely worship my power runner, which I've used recently at Bonnaroo and Summercamp to power my R-09HR...both times it finally ran out half-way through the last day of the festival.  So for summercamp, that was 3 1/2 days and for Bonnaroo that was 2 1/2 days, but the second day of Bonnaroo for me started at 12:00 noon and didn't end until 6:00am the next morning (moe latenight!)
Title: Re: Aerco MP-2 preamp - Part 2
Post by: spyder9 on July 05, 2009, 09:53:12 PM
The proper tip for the Aerco did come with the Tekkeon OEM package, btw.  Nice solid fit.
Title: Re: Aerco MP-2 preamp - Part 2
Post by: edtyre on July 05, 2009, 10:10:54 PM
I can't find a 3400, here's a MP3450. Would that work?

http://www.amazon.com/Tekkeon-MP3450-myPower-Rechargeable-Battery/dp/B000S9JWJI/ref=sr_1_1?ie=UTF8&s=electronics&qid=1246842100&sr=8-1

Because there's also a MP3450i. Not sure which is which or how they are different.

I bought one here for 82.00 and free shipping

http://www.buy.com/prod/tekkeon-mypower-all-plus-mp3450-10-extended-general-purpose-battery/q/loc/101/208787453.html

works great with my aerco and my r-44 like others have said
Title: Re: Aerco MP-2 preamp - Part 2
Post by: dactylus on July 06, 2009, 07:05:53 AM
I can't find a 3400, here's a MP3450. Would that work?

http://www.amazon.com/Tekkeon-MP3450-myPower-Rechargeable-Battery/dp/B000S9JWJI/ref=sr_1_1?ie=UTF8&s=electronics&qid=1246842100&sr=8-1

Because there's also a MP3450i. Not sure which is which or how they are different.

I bought one here for 82.00 and free shipping

http://www.buy.com/prod/tekkeon-mypower-all-plus-mp3450-10-extended-general-purpose-battery/q/loc/101/208787453.html

works great with my aerco and my r-44 like others have said

The buy.com link is for the MP3450-10 "extender" battery. It allows you to attach both  batteries in parallel...  The MP3450-10 "extender" can be used to be used in combination with the MP3450 to double your battery life.

Here is the Amazon link to both original battery + extender:



It appears that the MP3450i has only 5 adapter tips and the MP3450 has 9 adapter tips.  That seems to be the only difference.

http://www.amazon.com/Tekkeon-MP3450-myPower-Rechargeable-Battery/dp/B000S9JWJI/ref=sr_1_1?ie=UTF8&s=electronics&qid=1246842100&sr=8-1


Add myPower ALL Plus MP3450-10 Extended General Purpose Battery to myPower ALL Plus MP3450 battery or MP3700 battery and double your battery capacity. Bracket to connect two units is included. Must be used with myPower ALL Plus MP3450 or MP3700. It cannot be used independently.

That last statement appears to be incorrect, it sounds like the MP3450-10 is being used independently by Ed.
 

http://www.amazon.com/Tekkeon-myPower-Extended-Battery-MP3450-10/dp/B0017DS0SS/ref=pd_bxgy_e_text_b




Title: Re: Aerco MP-2 preamp - Part 2
Post by: edtyre on July 06, 2009, 09:58:36 AM
Add myPower ALL Plus MP3450-10 Extended General Purpose Battery to myPower ALL Plus MP3450 battery or MP3700 battery and double your battery capacity. Bracket to connect two units is included. Must be used with myPower ALL Plus MP3450 or MP3700. It cannot be used independently.

That last statement appears to be incorrect, it sounds like the MP3450-10 is being used independently by Ed.
 
http://www.amazon.com/Tekkeon-myPower-Extended-Battery-MP3450-10/dp/B0017DS0SS/ref=pd_bxgy_e_text_b


No, i screwed up. That's not what i got. Sorry! I bought a TEKKEON MP3300 MYPOWER
for that price and it works great. Although they look alike the 3450 is more powerful and has a 5v usb port as well.
Here's the correct link
http://www.buy.com/prod/tekkeon-lithium-polymer-battery-lithium-polymer-li-polymer-portable/q/loc/111/201658262.html
Here's a link to the differences
http://www.tekkeon.com/products-mypall-specs.html
Title: Re: Aerco MP-2 preamp - Part 2
Post by: manitouman on July 06, 2009, 10:31:46 AM
How many hours of run time did you get with the 3300?
Title: Re: Aerco MP-2 preamp - Part 2
Post by: edtyre on July 06, 2009, 05:22:43 PM
How many hours of run time did you get with the 3300?

Don't know how long? But i have used it a few times for 6-7 hours and only used two lights.
Same with the r-44  both @12volts

I'll add that for my 12 volt ad2k+ it won't power it past 3 hours
Title: Re: Aerco MP-2 preamp - Part 2
Post by: audBall on July 06, 2009, 05:33:13 PM
Don't forget, the 3450 has the ability to add the "extension pack" for double the capacity!

Not sure we'd need to run the Aerco for days, but I'm sure it's applicable somewhere.   ;)
Title: Re: Aerco MP-2 preamp - Part 2
Post by: manitouman on August 03, 2009, 03:12:28 PM
Got my Tekkeon and everything has been running great. Met a taper at Red Rocks who planted a seed of new ideas. So I've got the cables coming but wondered: Do I have to calibrate, if that's the term used, the Aerco with the SD702 like I had to do for the V3>SD702? With the V3>SD combo I run line in and then lowered the gain -5.0dB in each channel so that the gain would be accurate and match.

Anyone know if I have to do this with the Aerco? I still intend to run line in on the SD702.
Title: Re: Aerco MP-2 preamp - Part 2
Post by: spcyrfc on August 10, 2009, 11:13:38 PM
Add myPower ALL Plus MP3450-10 Extended General Purpose Battery to myPower ALL Plus MP3450 battery or MP3700 battery and double your battery capacity. Bracket to connect two units is included. Must be used with myPower ALL Plus MP3450 or MP3700. It cannot be used independently.

That last statement appears to be incorrect, it sounds like the MP3450-10 is being used independently by Ed.
 
http://www.amazon.com/Tekkeon-myPower-Extended-Battery-MP3450-10/dp/B0017DS0SS/ref=pd_bxgy_e_text_b


No, i screwed up. That's not what i got. Sorry! I bought a TEKKEON MP3300 MYPOWER
for that price and it works great. Although they look alike the 3450 is more powerful and has a 5v usb port as well.
Here's the correct link
http://www.buy.com/prod/tekkeon-lithium-polymer-battery-lithium-polymer-li-polymer-portable/q/loc/111/201658262.html
Here's a link to the differences
http://www.tekkeon.com/products-mypall-specs.html

does the USB port charge the batterY?
Title: Re: Aerco MP-2 preamp - Part 2
Post by: manitouman on August 10, 2009, 11:26:29 PM
^^^Not that I know of. The USB post provides 5v external power only. There is a DC in port that charges the battery.
Title: Re: Aerco MP-2 preamp - Part 2
Post by: spyder9 on April 11, 2011, 07:58:14 PM
Here is the part # Jerry uses for the Jensen transformers:

JT MB-CPC-A

http://www.jensen-transformers.com/datashts/mbcpca.pdf
Title: Re: Aerco MP-2 preamp - Part 2
Post by: spyder9 on April 11, 2011, 07:59:15 PM
Can anyone recommend a brand of Lithium 9v's?  Non-rechargeable.   How much runtime do you get over standard Alkaline's?

Thanks.
Title: Re: Aerco MP-2 preamp - Part 2
Post by: it-goes-to-eleven on April 11, 2011, 08:05:39 PM
Here is the part # Jerry uses for the Jensen transformers:

JT MB-CPC-A

http://www.jensen-transformers.com/datashts/mbcpca.pdf

He also builds versions with 20dB of transformer gain.  Those use different transformers.  I've wondered how the sound compares.
Title: Re: Aerco MP-2 preamp - Part 2
Post by: yug du nord on April 13, 2011, 07:26:53 PM
Anyone know when Jerry started to use Jensens?
Title: Re: Aerco MP-2 preamp - Part 2
Post by: OOK on April 13, 2011, 08:21:14 PM
Anyone know when Jerry started to use Jensens?


I want to say at least 2 or 3 years ago.......I remember him switching from cinamag to jensen but I forget the reason why.
Title: Re: Aerco MP-2 preamp - Part 2
Post by: it-goes-to-eleven on December 14, 2011, 12:29:44 PM
Hmm!

"Latest Member:  Jerry Chamkis"
Title: Re: Aerco MP-2 preamp - Part 2
Post by: yug du nord on December 14, 2011, 12:37:20 PM
Hmm!

"Latest Member:  Jerry Chamkis"

Hello Jerry.....   welcome!
Title: Re: Aerco MP-2 preamp - Part 2
Post by: F.O.Bean on December 14, 2011, 02:59:28 PM
Hmm!

"Latest Member:  Jerry Chamkis"

Hello Jerry.....   welcome!
Title: Re: Aerco MP-2 preamp - Part 2
Post by: macdaddy on December 14, 2011, 07:53:48 PM
welcome, jerry!
Title: Re: Aerco MP-2 preamp - Part 2
Post by: spyder9 on February 22, 2012, 10:09:23 AM
New feature for the Aerco MP-2:

Two (2) Lithium Polymer rechargeable batteries (helicopter) to power the unit internally.  This design would replace the "three 9V alkaline" setup.

$150 add-on for new builds.

$175 to mod existing units. 
Title: Re: Aerco MP-2 preamp - Part 2
Post by: cashandkerouac on February 22, 2012, 12:56:09 PM
New feature for the Aerco MP-2:

Two (2) Lithium Polymer rechargeable batteries (helicopter) to power the unit internally.  This design would replace the "three 9V alkaline" setup.

$150 add-on for new builds.

$175 to mod existing units.

i have the Aerco MP-2 with the helicopter rechargeable battery and i highly recommend this option.  i absolutely love my Aerco MP-2 and Jerry is absolutely wonderful to deal with.  A++ customer service.  thanks Jerry and welcome to the TS!!!
Title: Re: Aerco MP-2 preamp - Part 2
Post by: OOK on February 25, 2012, 12:41:41 PM
New feature for the Aerco MP-2:

Two (2) Lithium Polymer rechargeable batteries (helicopter) to power the unit internally.  This design would replace the "three 9V alkaline" setup.

$150 add-on for new builds.

$175 to mod existing units.

i have the Aerco MP-2 with the helicopter rechargeable battery and i highly recommend this option.  i absolutely love my Aerco MP-2 and Jerry is absolutely wonderful to deal with.  A++ customer service.  thanks Jerry and welcome to the TS!!!

I realize it depends on mics, but what is the average run times with the rechargeable batteries? also how long does it take to recharge the batteries.

One other question how do you turn the darn thing on and off? I don't see any switches?    peace OOK
Title: Re: Aerco MP-2 preamp - Part 2
Post by: spyder9 on February 25, 2012, 12:56:20 PM
There's a recessed 2 way switch on the back to turn it off.  Standard feature. 
Title: Re: Aerco MP-2 preamp - Part 2
Post by: F.O.Bean on February 26, 2012, 12:20:53 AM
There's a recessed 2 way switch on the back to turn it off.  Standard feature. 

All I want in life[for now :P ] is a KCY>PFA Cable to run any preamp I want to, and a PSP2/Aerco :P ;D 8) :)
Title: Re: Aerco MP-2 preamp - Part 2
Post by: aaronji on February 26, 2012, 03:36:11 PM
I realize it depends on mics, but what is the average run times with the rechargeable batteries? also how long does it take to recharge the batteries.

I don't know if this helps much, but Jerry said that the lithium polymers give longer run-times than the 3 9V version (which he claims gives ~ 10 hours of continuous use).  Curious about that myself. 

 
Title: Re: Aerco MP-2 preamp - Part 2
Post by: drewski1986 on February 28, 2012, 04:31:54 PM
Thinking about ordering one of these preamps.  Not sure if I want the stepped gain or variable.  That is the only question I am still trying to answer.  My R-44 has stepped gain so I am thinking I may want variable gain so I can raise or lower the gain smoothly.  I'm gonna email Jerry and see what the realistic wait time is.  If anyone knows of someone thinking about selling....that may be an option too.  ;)
Title: Re: Aerco MP-2 preamp - Part 2
Post by: acidjack on February 28, 2012, 04:55:28 PM
Thinking about ordering one of these preamps.  Not sure if I want the stepped gain or variable.  That is the only question I am still trying to answer.  My R-44 has stepped gain so I am thinking I may want variable gain so I can raise or lower the gain smoothly.  I'm gonna email Jerry and see what the realistic wait time is.  If anyone knows of someone thinking about selling....that may be an option too.  ;)

If I were you, I'd get stepped. Less likely to get bumped in the bag.  Your -44 has both stepped and variable, so it's easy enough to make small tweaks on it if necessary.  Personally, having variable on some of my other pres has always been a bit scary to me - I have definitely jostled the knob on my littlebox (luckily not during music) and made it move.

Jerry told me the current wait is 1mo, but we shall see  >:D
Title: Re: Aerco MP-2 preamp - Part 2
Post by: F.O.Bean on February 28, 2012, 04:57:13 PM
Thinking about ordering one of these preamps.  Not sure if I want the stepped gain or variable.  That is the only question I am still trying to answer.  My R-44 has stepped gain so I am thinking I may want variable gain so I can raise or lower the gain smoothly.  I'm gonna email Jerry and see what the realistic wait time is.  If anyone knows of someone thinking about selling....that may be an option too.  ;)

Wise choice. What mics do you have?

If I were you, Id go w/ variable gain so you can fine tune your levels. YMMV
Title: Re: Aerco MP-2 preamp - Part 2
Post by: yug du nord on February 28, 2012, 05:03:52 PM
I think that Jerry recommends stepped gain because the variable gain pots eventually get noisy and need to be replaced.  But I'm sure that would be years down the road for a new unit.  YMMV.
Title: Re: Aerco MP-2 preamp - Part 2
Post by: drewski1986 on February 28, 2012, 05:21:41 PM
I'll be running Neumann 140's/50's.  I tape about 30 shows a year so I don't think I'm worried about the pots getting noisy too soon.  I do kind of like the idea of being locked in with the step gain.  I have the best of both worlds with my V3 right now.  Just looking for something much smaller.
Title: Re: Aerco MP-2 preamp - Part 2
Post by: F.O.Bean on February 28, 2012, 06:33:58 PM
I personally like the sound of the LittleBox[with output transformers] better tha the Aerco, but thats just IMO. And as always, YMMV!
Title: Re: Aerco MP-2 preamp - Part 2
Post by: spyder9 on February 28, 2012, 07:22:14 PM
I vote YES for stepped gain on the Aerco.  I like setting it and forgetting it.
Title: Re: Aerco MP-2 preamp - Part 2
Post by: macdaddy on February 29, 2012, 09:59:31 AM
i opted for both, and balance ;)

and now that i think about it, s9, i think you asked about it a while ago; i will get some pics in this thread this afternoon...
Title: Re: Aerco MP-2 preamp - Part 2
Post by: drewski1986 on February 29, 2012, 11:18:02 AM
macdaddy, please up some pics.  I think i would like to do the same as you did.  I can see getting an m10 in the future and without a balance knob I don't think I could even out my l/r channels if I needed to.
Title: Re: Aerco MP-2 preamp - Part 2
Post by: twoodruff on February 29, 2012, 11:28:18 AM
new owner of an older beat up box. Yet to run because I have too many preamps currently. Hope to run at Wilco in May unless something else pops up, it usually does.
Title: Re: Aerco MP-2 preamp - Part 2
Post by: stober on February 29, 2012, 12:23:59 PM
I personally like the sound of the LittleBox[with output transformers] better tha the Aerco, but thats just IMO. And as always, YMMV!
crazy talk
I think that Jerry recommends stepped gain because the variable gain pots eventually get noisy and need to be replaced.  But I'm sure that would be years down the road for a new unit.  YMMV.
:coolguy:
Title: Re: Aerco MP-2 preamp - Part 2
Post by: ScoobieKW on February 29, 2012, 12:33:29 PM
new owner of an older beat up box. Yet to run because I have too many preamps currently. Hope to run at Wilco in May unless something else pops up, it usually does.

too many preamps? I'm looking for a budget pre, any you want to sell?
Title: Re: Aerco MP-2 preamp - Part 2
Post by: twoodruff on February 29, 2012, 01:20:51 PM
new owner of an older beat up box. Yet to run because I have too many preamps currently. Hope to run at Wilco in May unless something else pops up, it usually does.

too many preamps? I'm looking for a budget pre, any you want to sell?

none are very budget friendly. oade m148, aerco mp2, neve portico 5012 and the pre in the v3.
Title: Re: Aerco MP-2 preamp - Part 2
Post by: spyder9 on February 29, 2012, 01:32:33 PM
new owner of an older beat up box. Yet to run because I have too many preamps currently. Hope to run at Wilco in May unless something else pops up, it usually does.

too many preamps? I'm looking for a budget pre, any you want to sell?

none are very budget friendly. oade m148, aerco mp2, neve portico 5012 and the pre in the v3.

You need to go outside to the driveway and hose yourself off.  You're filthy!   ;D   
Title: Re: Aerco MP-2 preamp - Part 2
Post by: ScoobieKW on February 29, 2012, 04:03:31 PM
new owner of an older beat up box. Yet to run because I have too many preamps currently. Hope to run at Wilco in May unless something else pops up, it usually does.

too many preamps? I'm looking for a budget pre, any you want to sell?

none are very budget friendly. oade m148, aerco mp2, neve portico 5012 and the pre in the v3.

Well they could be budget friendly, if you were in a generous mood.

Just sayin'. ;D

Will likely end up with a Tinybox 2.0 or a custom Greedtone Pre. (He's got a design that he's been considering that would work well battery)
Title: Re: Aerco MP-2 preamp - Part 2
Post by: twoodruff on February 29, 2012, 04:47:58 PM
new owner of an older beat up box. Yet to run because I have too many preamps currently. Hope to run at Wilco in May unless something else pops up, it usually does.

too many preamps? I'm looking for a budget pre, any you want to sell?

none are very budget friendly. oade m148, aerco mp2, neve portico 5012 and the pre in the v3.

Well they could be budget friendly, if you were in a generous mood.

Just sayin'. ;D

Will likely end up with a Tinybox 2.0 or a custom Greedtone Pre. (He's got a design that he's been considering that would work well battery)

 ;)
Title: Re: Aerco MP-2 preamp - Part 2
Post by: Colin Liston on February 29, 2012, 06:19:04 PM
For someone who just got back in the game, that's a lot of pres!
Title: Re: Aerco MP-2 preamp - Part 2
Post by: F.O.Bean on March 01, 2012, 12:33:11 AM
For someone who just got back in the game, that's a lot of pres!

SLUT!
Title: Re: Aerco MP-2 preamp - Part 2
Post by: aaronji on March 01, 2012, 07:34:46 AM
I realize it depends on mics, but what is the average run times with the rechargeable batteries? also how long does it take to recharge the batteries.

I e-mailed Jerry to ask some battery related questions.  I know those lithium polymers are pretty picky about charging and discharging (and, potentially, spectacularly), so I inquired about that...He said that the charger contains a microprocessor subsystem which carefully controls the charging process (no real surprise there, I think) and that he builds a circuit into the MP-2 that disconnects the batteries when they drop to 3.1 V/cell.   He also said that charging takes about two hours...

As for run-time, he said that he has never really looked at run-time as a function of current draw, but that he gets more than 8 hours running a pair of AKG C451s (I am not sure what their current draw is at 48V or even to which 451 model he is referring)...

Jerry told me the current wait is 1mo, but we shall see  >:D

He told me about three weeks (that was about three weeks ago); of course, my order lenghtens the queue! ;)  He said he hopes to ship next week, which is close enough for me...

Title: Re: Aerco MP-2 preamp - Part 2
Post by: spyder9 on March 01, 2012, 09:54:47 AM
Jerry has mine.  It arrived 2 days ago.  I didn't ask how long it would take, but 3 weeks works for me.  As long as I have it for Wanee.

As for lithiums, Jerry's above response leaves no concerns.  A lithium is a lithium.  Much for reliable than NiMh. 

1)  Do you remove the bats to charge them or are they charged inside the case?

2)  Anybody care to upload a picture of the inside of the case?
Title: Re: Aerco MP-2 preamp - Part 2
Post by: spyder9 on March 01, 2012, 10:07:32 AM
A Beginner's guide to Helicopter Batteries.

http://myrcguide.com/index.php?topic=7059.0
Title: Re: Aerco MP-2 preamp - Part 2
Post by: OOK on March 01, 2012, 10:38:04 AM
I emailed Jerry with a couple of questions because I am seriously considering ordering a Aerco.  Here are his responses.  I asked him if it was ok to post since others may have the same questions and he said post away.  Peace OOK

> 1.    I have been told you prefer to use step gain for each channel is it
possible to get variable gain pots instead? I am looking for a db range of
0-50db.

Continuously variable pots are available and I now believe a better choice. My
original idea was that the switches would have a very long lifetime but of
course they make it impossible (or at least maximally disruptive) to change gain
during a recording. The pots are available in either smooth rotation or 11
detent steps. We've been using them for years and have yet to have one go noisy-
and they're easy to replace if they do fail.

> 2.    Can you order a MP-2 with continual variable gain for both channels on
one pot and balance control on the other pot?  I have a SoundDevice 702 with
this feature and love it. Is there any drawback to this type of set up in terms
of your pre?  I would still be looking for the same gain range 0-50db.

This also is doable. The only slight drawback is that the dual gain pot is not
available in the detented version, only the smooth rotation. The balance control
however can have a center detent if you wish.

> 3.    I have been told you use Jensen transformers currently.  Is that the
only option?  I know there are Cinemags and Lundahl.  Does this really matter or
do different transformers impart a different tonality to the pre?

We do indeed use Jensens.  They seem to have the widest name recognition and
some customers insist on them but we do our best to accommodate special
requests. We use the CineMag for the high gain (20 - 70 dB) version as Jensen
doesn't make that transformer in a P.C. mount. I've heard about the Lundahls but
never used them. We have a very high precision LabVIEW analysis system and there
is no measurable difference between the Jensens and CineMags. The idea is for
the transformer to be completely transparent and not color the signal at all but
it would take a person with golden ears to pronounce any difference in the
sound.  The ear is a marvelously subtle analyzer- check out the level of
echolocation that some blind people can achieve. The MP-2 is very densely packed
and any alternate transformers would need to be absolutely no larger.  (28.5 mm
diameter, 21 mm high)

> 4.    I understand you now offer an internal rechargeable battery option. How
long does it take to reach a full charge?  What is the average expected run
times?  I realize this will depend on microphone draw.  The mics I will mostly
use with this pre would be the following:
> Mbho 648- which have a draw of 1.7mA
> Gefell SMS 210- which have a draw of 3mA
> Nevaton MC49- which have a draw of 10mA – I don’t believe this number is
accurate tho.

They recharge in a couple of hours. Run time with no phantom load is about 40
hours, at ten ma (the Neuman RSM-190i (?) matrix mic draws 10 ma- one of the
Aerco's early claims to fame in the film industry was that it was the only
portable pre to power it) I'd guess 6 - 8 hours. At 1.7 ma I'd guess on the
order of 15 - 20 hours but I'm ashamed to say I haven't made these measurements
. I have a very long to-do list!  In any case, there is a protective circuit
that shuts the preamp off when the batteries reach their minimum allowable
voltage. This prevents damage to the batteries but there is no warning unless
you carry a voltmeter around with you.

> 5.    With the internal rechargeable battery is it still possible to hook up
an external battery or AC for even more extended times.  I am thinking in terms
of several day festivals where extended run times are needed.  Is this possible
even if the internal battery dies.

Yes- the external power jack is active all the time. It accepts 8 - 16 volts
D.C. any polarity, any ground. As long as the external voltage is greater than
the battery voltage, the batteries are not discharged. Note that the power
switch only controls the internal batteries- the external jack is always on so
you would have to disconnect an external battery when not in use.

> 6.    Is there a on / off switch. For the pre.  I can’t really tell from your
photos on your website.  If so how easy is it to switch.  I don’t want to
accidentally turn it off if my bag gets moved or kicked.

Yes, there is a recessed slide switch on the back. It's pretty hard to change
accidentally. We can optionally ($25)  put a locking toggle switch on the front
instead of the 3.5 mm phone jack output- but that may not fit if you choose the
pots.
Title: Re: Aerco MP-2 preamp - Part 2
Post by: page on March 01, 2012, 11:11:43 AM
(havn't looked back so please excuse the redundant question if it's already answered somewhere):

Has anyone inquired about a balanced out, say on a 6-pin mini-xlr or binder plug instead of the RCA jacks?

Also, what's the max dbu before clipping that the aerco can put out?
Title: Re: Aerco MP-2 preamp - Part 2
Post by: F.O.Bean on March 01, 2012, 09:59:41 PM
I emailed Jerry with a couple of questions because I am seriously considering ordering a Aerco.  Here are his responses.  I asked him if it was ok to post since others may have the same questions and he said post away.  Peace OOK

> 1.    I have been told you prefer to use step gain for each channel is it
possible to get variable gain pots instead? I am looking for a db range of
0-50db.

Continuously variable pots are available and I now believe a better choice. My
original idea was that the switches would have a very long lifetime but of
course they make it impossible (or at least maximally disruptive) to change gain
during a recording. The pots are available in either smooth rotation or 11
detent steps. We've been using them for years and have yet to have one go noisy-
and they're easy to replace if they do fail.

> 2.    Can you order a MP-2 with continual variable gain for both channels on
one pot and balance control on the other pot?  I have a SoundDevice 702 with
this feature and love it. Is there any drawback to this type of set up in terms
of your pre?  I would still be looking for the same gain range 0-50db.

This also is doable. The only slight drawback is that the dual gain pot is not
available in the detented version, only the smooth rotation. The balance control
however can have a center detent if you wish.

> 3.    I have been told you use Jensen transformers currently.  Is that the
only option?  I know there are Cinemags and Lundahl.  Does this really matter or
do different transformers impart a different tonality to the pre?

We do indeed use Jensens.  They seem to have the widest name recognition and
some customers insist on them but we do our best to accommodate special
requests. We use the CineMag for the high gain (20 - 70 dB) version as Jensen
doesn't make that transformer in a P.C. mount. I've heard about the Lundahls but
never used them. We have a very high precision LabVIEW analysis system and there
is no measurable difference between the Jensens and CineMags. The idea is for
the transformer to be completely transparent and not color the signal at all but
it would take a person with golden ears to pronounce any difference in the
sound.  The ear is a marvelously subtle analyzer- check out the level of
echolocation that some blind people can achieve. The MP-2 is very densely packed
and any alternate transformers would need to be absolutely no larger.  (28.5 mm
diameter, 21 mm high)

> 4.    I understand you now offer an internal rechargeable battery option. How
long does it take to reach a full charge?  What is the average expected run
times?  I realize this will depend on microphone draw.  The mics I will mostly
use with this pre would be the following:
> Mbho 648- which have a draw of 1.7mA
> Gefell SMS 210- which have a draw of 3mA
> Nevaton MC49- which have a draw of 10mA – I don’t believe this number is
accurate tho.

They recharge in a couple of hours. Run time with no phantom load is about 40
hours, at ten ma (the Neuman RSM-190i (?) matrix mic draws 10 ma- one of the
Aerco's early claims to fame in the film industry was that it was the only
portable pre to power it) I'd guess 6 - 8 hours. At 1.7 ma I'd guess on the
order of 15 - 20 hours but I'm ashamed to say I haven't made these measurements
. I have a very long to-do list!  In any case, there is a protective circuit
that shuts the preamp off when the batteries reach their minimum allowable
voltage. This prevents damage to the batteries but there is no warning unless
you carry a voltmeter around with you.

> 5.    With the internal rechargeable battery is it still possible to hook up
an external battery or AC for even more extended times.  I am thinking in terms
of several day festivals where extended run times are needed.  Is this possible
even if the internal battery dies.

Yes- the external power jack is active all the time. It accepts 8 - 16 volts
D.C. any polarity, any ground. As long as the external voltage is greater than
the battery voltage, the batteries are not discharged. Note that the power
switch only controls the internal batteries- the external jack is always on so
you would have to disconnect an external battery when not in use.

> 6.    Is there a on / off switch. For the pre.  I can’t really tell from your
photos on your website.  If so how easy is it to switch.  I don’t want to
accidentally turn it off if my bag gets moved or kicked.

Yes, there is a recessed slide switch on the back. It's pretty hard to change
accidentally. We can optionally ($25)  put a locking toggle switch on the front
instead of the 3.5 mm phone jack output- but that may not fit if you choose the
pots.


Thanks for the info bro :)
Title: Re: Aerco MP-2 preamp - Part 2
Post by: aaronji on March 09, 2012, 04:41:40 PM
Jerry told me the current wait is 1mo, but we shall see  >:D

He told me about three weeks (that was about three weeks ago); of course, my order lenghtens the queue! ;)  He said he hopes to ship next week, which is close enough for me...

Jerry shipped 3 weeks and 6 days after my wire transfer went through.  A little longer than the three weeks originally estimated, but not by much.  Personally, I don't mind a few extra days...Actually, much closer to the estimated delivery schedule than a couple of other transactions with popular equipment vendors here.

Also, what's the max dbu before clipping that the aerco can put out?

20V peak-to-peak...
Title: Re: Aerco MP-2 preamp - Part 2
Post by: Thom Joad on March 11, 2012, 07:33:23 AM
Has anyone inquired about a balanced out, say on a 6-pin mini-xlr or binder plug instead of the RCA jacks?

Mine is a bit older and has dual, pigtailed, 3-pin, XLR balanced outs.  Awesome for going into my 661.
Title: Re: Aerco MP-2 preamp - Part 2
Post by: page on March 11, 2012, 03:24:52 PM
Has anyone inquired about a balanced out, say on a 6-pin mini-xlr or binder plug instead of the RCA jacks?

Mine is a bit older and has dual, pigtailed, 3-pin, XLR balanced outs.  Awesome for going into my 661.

neato, so it is something he's at least willing to humor on occasion.

Also, what's the max dbu before clipping that the aerco can put out?

20V peak-to-peak...

awesome. thanks!
Title: Re: Aerco MP-2 preamp - Part 2
Post by: drewski1986 on March 11, 2012, 03:27:19 PM
I've go one on order so I'm going to need to order some interconnects.  What seems to work best with the aerco.  I'm thinking right angle rca's for the output and stubby xlr's exiting at 12:00 (which would be toward the bottom).  Anyone have any suggestions before I order?  Thanks.
Title: Re: Aerco MP-2 preamp - Part 2
Post by: spyder9 on March 11, 2012, 04:37:33 PM
I've go one on order so I'm going to need to order some interconnects.  What seems to work best with the aerco.  I'm thinking right angle rca's for the output and stubby xlr's exiting at 12:00 (which would be toward the bottom).  Anyone have any suggestions before I order?  Thanks.

Contact Ted Gakidis.  He made both cables for my Aerco: 

1) right angle stubby female XLR > straight stubby male XLR - pair of cables

2) right angle dual stubby RCA > right angle 3.5mm stereo - Y cable

Title: Re: Aerco MP-2 preamp - Part 2
Post by: aaronji on March 13, 2012, 05:15:08 PM
^^^ I also got chopped straight males for the Aerco end.  They stick out (more or less) the same amount as the gain knobs...
Title: Re: Aerco MP-2 preamp - Part 2
Post by: drewski1986 on March 13, 2012, 07:38:44 PM
^^Thanks. I'm going with straight stubbies into the aerco.  At first I thought r/a stubbies but now after looking at it, straight stubbies will be fine.  r/a rca's out to stubby xlr's into my r-44 and I'm all set.
Title: Re: Aerco MP-2 preamp - Part 2
Post by: stober on March 13, 2012, 08:35:58 PM
^^Thanks. I'm going with straight stubbies into the aerco.  At first I thought r/a stubbies but now after looking at it, straight stubbies will be fine.  r/a rca's out to stubby xlr's into my r-44 and I'm all set.
Nice move Drew getting an Aerco.
Title: Re: Aerco MP-2 preamp - Part 2
Post by: spyder9 on April 03, 2012, 10:11:45 AM
Jerry's new email address:

jerry@jchamkis.com


His old address will be ending soon.  Please update your personal contact list.
Title: Re: Aerco MP-2 preamp - Part 2
Post by: spyder9 on April 08, 2012, 11:21:08 AM
My Aerco is on its way back from Jerry, with the new lithium mod.  Just in time for Wanee.  I'll up pictures of the mod later in the week. 
Title: Re: Aerco MP-2 preamp - Part 2
Post by: acidjack on April 10, 2012, 02:03:03 PM
My Aerco is on its way back from Jerry, with the new lithium mod.  Just in time for Wanee.  I'll up pictures of the mod later in the week.

Just got mine.  Sure is pretty.  And nice and compact. The only not-compact component is the enormous AC adapter... It's like 2x the size of the unit!  But who cares - it works!

Also can be powered, per Jerry, through the input in the side of the MP-2, 9-12V, either polarity.  So in a pinch, I could stick a DVD batt or Tekkeon in there and keep going....

Title: Re: Aerco MP-2 preamp - Part 2
Post by: aaronji on April 10, 2012, 02:51:59 PM
^^^ He also said you can run it AC via the charger (although it is pretty huge).  Maybe you won't need external power too often, though.  I haven't done a full battery test, but I did run it for 6.5 hours on the lithium polymers with no problems (P48, 2.8 mA per channel)...
Title: Re: Aerco MP-2 preamp - Part 2
Post by: spyder9 on April 13, 2012, 07:50:34 AM
Pictures of the Lithium mod.  The AC adapter is custom made and larger than the MP-2.  Jerry added the charging connector on the back, so the batteries never leave the unit. 
Title: Re: Aerco MP-2 preamp - Part 2
Post by: spyder9 on April 13, 2012, 07:52:08 AM
A few more....
Title: Re: Aerco MP-2 preamp - Part 2
Post by: aaronji on April 13, 2012, 09:15:56 AM
^^^ What is the switch protruding from the left-hand side (with the knobs facing you)? 
Title: Re: Aerco MP-2 preamp - Part 2
Post by: spyder9 on April 13, 2012, 09:20:22 AM
^^^ What is the switch protruding from the left-hand side (with the knobs facing you)?

3 way switch for turning off the phantom power, so I can operate as a straight preamp.  Comes in handy when your transferring tapes, recording off the SBD, etc.
Title: Re: Aerco MP-2 preamp - Part 2
Post by: Myco on April 13, 2012, 09:43:23 AM
I'm curious about what you really gain with this lithium battery mod? I've been running my Aerco with internal 9V's connected as a backup, but using a lithium dvd battery connected as the main power source, and I've been able to run for an entire weekend festival without any concern for battery power. I see no benefit to this if it is only to get rid of using alkaline batteries. I've suffered no dropouts, noise introduced to my recordings, or anything negative in using it the way that I have been using it. It's not that much bigger a footprint in actual use, and much smaller that that big charger block for house power, just a wal-wart cord that plugs into the dvd battery for charging.
Title: Re: Aerco MP-2 preamp - Part 2
Post by: spyder9 on April 13, 2012, 09:56:03 AM
The external bat connector on my Aerco is unreliable.  The Ratshack connectors don't provide a tight connection for me.  So I've been running the Aerco on alkalines for past couple of years.  That said, I hate buying alkalines and using bat snaps.  Pain in the arse.  I do like the convenience of having 1 less thing in the bag to connect, like an external battery.  So, this mod provides me a "peace of mind."  I can also run in the smallest bag possible.           
Title: Re: Aerco MP-2 preamp - Part 2
Post by: it-goes-to-eleven on April 13, 2012, 10:00:01 AM
Thanks for the pics.  Obviously, not a trivial mod for Jerry to add.

I also run on a dvd battery.  I haven't had any noise issues, but the regulators in those batteries do generate noise - some probably more than others.

My external power jack has been fine. I use a bit of gaffer tape to hold the plug in.  I haven't done the v3 rubberband mod, but may be I should...
Title: Re: Aerco MP-2 preamp - Part 2
Post by: Myco on April 13, 2012, 10:04:04 AM
The external bat connector on my Aerco is unreliable.  The Ratshack connectors don't provide a tight connection for me.  So I've been running the Aerco on alkalines for past couple of years.  That said, I hate buying alkalines and using bat snaps.  Pain in the arse.  I do like the convenience of have 1 less thing in the bag to connect (external battery).  So, this mod provides me a "peace of mind."  I can also run in the smallest bag possible.         

Ahh, ok, it's a personal preference type of thing. I use a right angle connector on the power cord, then I put a small piece of gaffers tape over the end of it and tape it to the MP-2 to hold it tight, just in case. I do get a tight connection on mine though. I leave the taped power cable connected to the MP-2 and just disconnect it from the dvd battery when not in use. That way there is never any unnecessary power draw on the internal 9V alkaline backups.
Title: Re: Aerco MP-2 preamp - Part 2
Post by: aaronji on April 13, 2012, 10:04:19 AM
^^^ What is the switch protruding from the left-hand side (with the knobs facing you)?

3 way switch for turning off the phantom power, so I can operate as a straight preamp.  Comes in handy when your transferring tapes, recording off the SBD, etc.

Cool...I kind of figured it might be related to power when I saw that you have a piece of tape where the normal on/off switch is located!

I'm curious about what you really gain with this lithium battery mod? I've been running my Aerco with internal 9V's connected as a backup, but using a lithium dvd battery connected as a main source, and I've been able to run for an entire weekend festival without any concern for battery power. I see no benefit to this if it is only to get rid of using alkaline batteries. I've suffered no dropouts, noise introduced to my recordings, or anything negative in using it the way that I have been using it. It's not that much bigger a footprint in actual use, and much smaller that that big charger block for house power, just a wal-wart cord that plugs into the dvd battery for charging.

Really, the advantage is not having to run through all of those alkalines (and not having to open the case to change them).  Plus Jerry says the run-times are longer than with alkalines.

As for external powering, you can still run it the same way as with a non-lithium Aerco.  The charge connector and the external power connector are separate; Jerry says there is no problem using them in any combination...

Title: Re: Aerco MP-2 preamp - Part 2
Post by: spyder9 on April 13, 2012, 10:34:15 AM
The external bat connector on my Aerco is unreliable.  The Ratshack connectors don't provide a tight connection for me.  So I've been running the Aerco on alkalines for past couple of years.  That said, I hate buying alkalines and using bat snaps.  Pain in the arse.  I do like the convenience of have 1 less thing in the bag to connect (external battery).  So, this mod provides me a "peace of mind."  I can also run in the smallest bag possible.         

Ahh, ok, it's a personal preference type of thing. I use a right angle connector on the power cord, then I put a small piece of gaffers tape over the end of it and tape it to the MP-2 to hold it tight, just in case. I do get a tight connection on mine though. I leave the taped power cable connected to the MP-2 and just disconnect it from the dvd battery when not in use. That way there is never any unnecessary power draw on the internal 9V alkaline backups.

Which bat connector do you use to connect to the Aerco?  Ratshack connector or what came with the DVD battery?

You are correct on disconnecting the dvd battery.  Jerry says that the unit is always on when connected to an external battery.  The on/off switch does not work for external battery setup.
Title: Re: Aerco MP-2 preamp - Part 2
Post by: Myco on April 13, 2012, 10:35:41 AM
The external bat connector on my Aerco is unreliable.  The Ratshack connectors don't provide a tight connection for me.  So I've been running the Aerco on alkalines for past couple of years.  That said, I hate buying alkalines and using bat snaps.  Pain in the arse.  I do like the convenience of have 1 less thing in the bag to connect (external battery).  So, this mod provides me a "peace of mind."  I can also run in the smallest bag possible.         

Ahh, ok, it's a personal preference type of thing. I use a right angle connector on the power cord, then I put a small piece of gaffers tape over the end of it and tape it to the MP-2 to hold it tight, just in case. I do get a tight connection on mine though. I leave the taped power cable connected to the MP-2 and just disconnect it from the dvd battery when not in use. That way there is never any unnecessary power draw on the internal 9V alkaline backups.

Which bat connector do you use to connect to the Aerco?  Ratshack connector or what came with the DVD battery?

Just a RatShack "M" tip I believe, I can check for you once I get home.
Title: Re: Aerco MP-2 preamp - Part 2
Post by: spyder9 on April 13, 2012, 10:50:50 AM
BTW,  I upgraded the RCA connectors last year to Neutrik NYS367.  I bought them from Dale Pro Audio for $12.25 shipped.  I did the soldering myself.  The original connectors were of a chinese variety and became worn over time.  The Neutriks are a little longer than the originals and provided a tighter connection.   
Title: Re: Aerco MP-2 preamp - Part 2
Post by: Myco on April 13, 2012, 11:03:54 AM
BTW,  I upgraded the RCA connectors last year to Neutrik NYS367.  I bought them from Dale Pro Audio for $12.25 shipped.  I did the soldering myself.  The original connectors were of a chinese variety and became worn over time.  The Neutriks are a little longer than the originals and provided a tighter connection.   

Thanks for the info spyder. I don't have a need for them now, but may in the future.  :coolguy:
Title: Re: Aerco MP-2 preamp - Part 2
Post by: spyder9 on April 23, 2012, 02:50:20 PM
Everything went well at the Wanee festival this weekend.  Recorded 8 hours of music on the Peach Stage each day, with no issues.

Hot blazing sun did not affect the LIPO bats. 

Charging time is approximately 4 1/2 hours.


I am  :) with my purchase.   
Title: Re: Aerco MP-2 preamp - Part 2
Post by: drewski1986 on April 28, 2012, 11:38:50 AM
Received my aerco this week.  I can't believe how tight it is in the case.  Putting in and taking out the 9V batts is really tight.  I can't get them in without moving the power supply board a little bit.  Hoping this won't hurt anything.  I tried all of my tips that came with my tekkeons and can't seem to get a good tight fit with any of them.  Any suggestions on getting the tekkeon to work well with the aerco?  My original plan was to just use the 9 volt batteries, but I don't know if I want to change them a lot if I'm going to be moving stuff around on the inside each time I change batteries.
Title: Re: Aerco MP-2 preamp - Part 2
Post by: it-goes-to-eleven on April 28, 2012, 12:11:57 PM
I just use a piece of gaffer tape to hold the power plug in, and never had a problem.  It has been more reliable than the flawed screw-in design on the v3.  It's the same size tip as the v3 and psp2.
Title: Re: Aerco MP-2 preamp - Part 2
Post by: spyder9 on April 29, 2012, 09:50:56 AM
The bat snap Jerry uses for the 9Vs are cheap and difficult to pry apart.  I agree with that.  I had upgraded mine, at one time, to a hard plastic snap.  The only drawback of this snap was positioning the batteries in the case to get the cover on.  The HD snaps take up a tiny bit of head room, because they are inflexible.   
Title: Re: Aerco MP-2 preamp - Part 2
Post by: cashandkerouac on May 17, 2012, 01:52:51 PM
one more shameless plug for the Aerco MP-2.  boy oh boy, do i LOOOOOOOOOOOOVE my MP-2!   ;D
Title: Re: Aerco MP-2 preamp - Part 2
Post by: drewski1986 on May 23, 2012, 04:30:10 PM
I contacted Jerry about not being able to fit 3 9 volts in my aerco correctly.  I sent it back to him and he found the screws that were used for the xlr's were too long and got in the way of the main board causing the open space for the batteries to be too small.  He fixed it very quickly and when I got it back he also enclosed a check to cover my end of the shipping.  Everything is good now.  I also had Ted make a power cable for my tekkeon.  He modified a straight cable into a right angle cable and it will work fine.  Now I have both options for powering the aerco.  I'll run it for Kimock next Friday for the first time.
Title: Re: Aerco MP-2 preamp - Part 2
Post by: twoodruff on May 31, 2012, 07:20:03 PM
which tekkeon are people using?
Title: Re: Aerco MP-2 preamp - Part 2
Post by: Myco on May 31, 2012, 08:04:33 PM
which tekkeon are people using?

I've used the 3350 & 3450 with it. No issues really because it accepts variable voltages.
Title: Re: Aerco MP-2 preamp - Part 2
Post by: F.O.Bean on May 31, 2012, 09:00:24 PM
I want an MP-2 too :( ;D
Title: Re: Aerco MP-2 preamp - Part 2
Post by: twoodruff on June 01, 2012, 12:31:41 AM
I want an MP-2 too :( ;D

trade you one for your sax, if you just want to try one.
Title: Re: Aerco MP-2 preamp - Part 2
Post by: yug du nord on June 01, 2012, 09:15:09 AM
which tekkeon are people using?

the 9volt DVD batteries work great too.
Title: Re: Aerco MP-2 preamp - Part 2
Post by: acidjack on June 01, 2012, 03:35:38 PM
which tekkeon are people using?

I've used the 3350 & 3450 with it. No issues really because it accepts variable voltages.

Yup. Jerry also claims it can even accept either polarity (i.e., an R-44 DVD batt cable or a normal one)
Title: Re: Aerco MP-2 preamp - Part 2
Post by: aaronji on June 06, 2012, 08:32:17 AM
I contacted Jerry about not being able to fit 3 9 volts in my aerco correctly.  I sent it back to him and he found the screws that were used for the xlr's were too long and got in the way of the main board causing the open space for the batteries to be too small.  He fixed it very quickly and when I got it back he also enclosed a check to cover my end of the shipping.  Everything is good now.  I also had Ted make a power cable for my tekkeon.  He modified a straight cable into a right angle cable and it will work fine.  Now I have both options for powering the aerco.  I'll run it for Kimock next Friday for the first time.

Jerry seems like a pretty good guy.  It's nice to hear that he fixed your problem so quickly!  When I got my Aerco, he quoted me a shipping price that ended up being about half of the actual cost (and it was a lot).  He didn't even mention the increase, let alone ask for more money; I only noticed it when I got the package...I basically had to force him to take some more cash (he felt that he should honor his quote, whereas I, having dealt with a bunch of these international shipments, expect some fluctuations with shipping costs)...
Title: Re: Aerco MP-2 preamp - Part 2
Post by: F.O.Bean on June 07, 2012, 08:08:55 PM
I want an MP-2 too :( ;D

trade you one for your sax, if you just want to try one.

Cant do it, sorry Trey! I just love my mk41>Sax sound :)
Title: Re: Aerco MP-2 preamp - Part 2
Post by: drewski1986 on June 20, 2012, 11:47:11 AM
still learning how to use this preamp.  brickwalled at phish last night.  Gonna turn it down a bit tonight.  I wish it had an overload light on it.
Title: Re: Aerco MP-2 preamp - Part 2
Post by: acidjack on June 20, 2012, 12:43:49 PM
still learning how to use this preamp.  brickwalled at phish last night.  Gonna turn it down a bit tonight.  I wish it had an overload light on it.

Anecdotally, I'd very careful ever going over 20dB gain, and consider using 10. When I run it at 20 for most shows, I have to turn the R-44 input gain to 9 o'clock (i.e., pretty far down).

But yes, an overload light would be nice.
Title: Re: Aerco MP-2 preamp - Part 2
Post by: aaronji on June 20, 2012, 02:01:40 PM
It's probably worth measuring how much gain you are actually adding at each step of the way too.  I forget the exact explanation (I'll try to find the e-mail), but Jerry told me that the pots have uneven gain steps.  Close together at the low end and further apart at the high end.  The markings on the front are for the switches.  I did measure this when I first got mine; I'll try to find that too...
Title: Re: Aerco MP-2 preamp - Part 2
Post by: Craig T on June 20, 2012, 04:29:20 PM
still learning how to use this preamp.  brickwalled at phish last night.  Gonna turn it down a bit tonight.  I wish it had an overload light on it.

Brickwalled the recorder's input or overloaded the Aerco?  You may have had plenty of headroom left on the Aerco but still brickwalled your recorder's input - in this case an overload light on th Aerco doesn't help you.  What's the rig?
Title: Re: Aerco MP-2 preamp - Part 2
Post by: drewski1986 on June 21, 2012, 08:22:53 AM
I'm running neumann ak 40/50's > aerco > (ocm) R-44.  Last night I ran it at about 25 and still had slight brickwalling.  I have a single variable gain pot on my aerco as well as a balance knob.  It looks to me as if the right channel is worse than the left.  I am thinking that I am overloading the pre since I never saw the overload indicators on the R-44 light up.  Trying to figure out how to post a screen shot of the wav files in audacity but haven't figured it out yet.  Forgot to add that the R-44 was one click up from the bottom (outer knob -2, inner knob at 12:00)
Title: Re: Aerco MP-2 preamp - Part 2
Post by: it-goes-to-eleven on June 21, 2012, 09:42:59 AM
What was the show/material?  How loud was it?

I am surprised you would have this issue with the Aerco.  I've run my Aerco in pretty crazy-loud situations on stage, etc.
Title: Re: Aerco MP-2 preamp - Part 2
Post by: drewski1986 on June 21, 2012, 10:04:41 AM
Phish shows the last two nights.  It was loud.
Title: Re: Aerco MP-2 preamp - Part 2
Post by: bhadella on June 21, 2012, 10:14:50 AM
If your connecting the rca outputs of the MP-2 to the XLR inputs of the R44, you will need to increase the gain on the R44 (-8 db would be a good start) to insure that the R44 and MP-2 will clip (or be in the tapers world definition of unity) at the same levels.   A typical  consumer rca signal is 10-14 db lower than full XLR signal (like that which the R44 can receive). 
Title: Re: Aerco MP-2 preamp - Part 2
Post by: acidjack on June 21, 2012, 11:50:42 AM
If your connecting the rca outputs of the MP-2 to the XLR inputs of the R44, you will need to increase the gain on the R44 (-8 db would be a good start) to insure that the R44 and MP-2 will clip (or be in the tapers world definition of unity) at the same levels.   A typical  consumer rca signal is 10-14 db lower than full XLR signal (like that which the R44 can receive).

I'm not sure what you mean by "increase" the gain on the -44?

When I run the Aerco for any kind of rock music, I basically have three options:

10dB gain/R-44 at its default 12 o'clock or maybe down at 10 or 11 o'clock to get not-too-hot levels (I don't recall without looking at it what these gain settings are, but any -44 owners will know what I mean).
20dB gain/R-44 at 9 o'clock or 8 o'clock to get not-too-hot levels
30dB gain pretty much only if it's acoustic or less-amplified stuff.  For example, I've recorded a few shows at Joe's Pub in NYC, like The Wandering, where I ran the Aerco up to +30dB into the M10 with the M10 at 4 on the level knob, yielding levels that peaked around -6dB.

I can't imagine adding yet more gain to the R-44 on its end; your levels would go way over.  Also, I would think the point of running the MP-2 would be to get gain from the pre and not the -44, so wouldn't the better method be to turn DOWN the -44 until you get decent levels?
Title: Re: Aerco MP-2 preamp - Part 2
Post by: drewski1986 on June 21, 2012, 11:52:59 AM
Thanks for all of the input.  I am not really up on the technical details of this hobby.  After looking at the waveforms closer, I don't think I did brickwall.  My levels came out much lower than usual.  I have been running a V3 and seem to be able to dial that pre in pretty easily.  Still learning with the aerco.  Anyway, I amplified my wav files about 5 db and I can see that there are peaks above what I thought was brickwalling.  Again, I could be using the wrong terms here and I apologize for my ignorance.  I am going to try to raise the R-44 to -8 as suggested and see how that works out.  Thanks again for all of the knowledge.
Title: Re: Aerco MP-2 preamp - Part 2
Post by: drewski1986 on June 21, 2012, 11:55:31 AM
-8 on the R-44 is at 9:00 (outer knob) I think.
Title: Re: Aerco MP-2 preamp - Part 2
Post by: justink on June 21, 2012, 02:18:01 PM
I'm running neumann ak 40/50's > aerco > (ocm) R-44.  Last night I ran it at about 25 and still had slight brickwalling.  I have a single variable gain pot on my aerco as well as a balance knob.  It looks to me as if the right channel is worse than the left.  I am thinking that I am overloading the pre since I never saw the overload indicators on the R-44 light up.  Trying to figure out how to post a screen shot of the wav files in audacity but haven't figured it out yet.  Forgot to add that the R-44 was one click up from the bottom (outer knob -2, inner knob at 12:00)

imho, ditch the aerco.  you've got an OCM R-44.  the aerco is an un-needed liability in the chain.

just use it for stealthy shows.
Title: Re: Aerco MP-2 preamp - Part 2
Post by: Todd R on June 21, 2012, 03:52:36 PM
Brickwalling seems to be the term around here for getting unwanted distortion.  Whether that is a correct usage, I don't know.  Also, it is never clear whether the distortion is because the SPLs are too high and the mic distorts, or if the external preamp distorts on it input (mic input too hot), or the preamp distorts on its output (preamp trying to send a louder signal than it is designed for, due to gain levels being set too high), or whether the recorder is distorting on its analog input since the signal coming from the preamp is too high, or if the recorder is distorting since you are trying to go above 0dbFS (db Full Scale -- digital 1's and 0's can only be negative or get up to 0 max, beyond that isn't possible and you have clipping).

If you brickwalled -- ie, ended up with a distorted recording -- it could have come from any of the above. 

Or even one more option: when I had the OCM R44, one thing I didn't like is that the inner variable gain goes from -infinity (no signal) to max signal, and then the outer stepped ring provided the single gain setting, much like the V3.  But if you have the outer gain set too high, and then dial back the inner variable gain, the R44 can distort, but you don't know it since there are no clip meters to tell you it's happening and your levels aren't hitting 0dbFS.

I had this problem once or twice.  I forgot now what the solution is.  I think it's something like you should never go lower than 12:00 on the inner variable gain setting, and if your levels are too hot and you're clipping (trying to go above 0dbFS), then you should dial back the stepped gain.  If you keep the stepped gain where it is and go below a certain point on the variable gain (9:00, 10:00, 11:00?? I don't recall anymore) you can get brickwalling/distortion.
Title: Re: Aerco MP-2 preamp - Part 2
Post by: aaronji on June 21, 2012, 04:17:15 PM
^^^ It's kind of hard to overload the Aerco's input, I think.  I recently recorded a deafeningly loud show with quite sensitive (40 mV/Pa) mics and had no problems.  The output can do 20V peak-to-peak; I am pretty sure I could have distorted that if I had added a bunch of gain on the pre.  I would probably have been overloading the recorder input (or been close) with that sort of gain setting, though.

As I mentioned in my previous post, here is what Jerry said about the gain pots in response to my question about how the gain settings correspond to the pot detents and the stickers on the front of the pre:

Quote from: Jerry
It's because the pots have a linear slope which causes uneven gain steps. The markings on the front are for the switches, only 180 degrees of rotation. The gain is different for each step but the steps are closely spaced at the low end and widely spaced at the high end. The other commonly available slope for potentiometers is audio (logarithmic) slope which would be much worse.
Title: Re: Aerco MP-2 preamp - Part 2
Post by: twoodruff on September 25, 2012, 09:08:25 AM
Anyone know if Jerry will look over a unit and give it a "clean bill of health", I am trading mine to someone who will get more use out of it.
Title: Re: Aerco MP-2 preamp - Part 2
Post by: twoodruff on September 25, 2012, 09:57:51 AM
Anyone know if Jerry will look over a unit and give it a "clean bill of health", I am trading mine to someone who will get more use out of it.

Nevermind, i received a response from Jerry. FYI he is asking $25 plus shipping for this service which seems very reasonable to me.
Title: Re: Aerco MP-2 preamp - Part 2
Post by: Myco on September 26, 2012, 07:46:50 AM
The Aerco and the R-44 don't play well together, the Aerco overwhelms the R-44's input very easily. I had the same issues when I ran a R-44. Never got it fully worked out.
Title: Re: Aerco MP-2 preamp - Part 2
Post by: spyder9 on September 26, 2012, 08:59:22 AM
Same thing happened to Gutbucket a few weeks ago when he used my Aerco with his R44. 
Title: Re: Aerco MP-2 preamp - Part 2
Post by: Myco on September 26, 2012, 10:38:20 AM
I wonder if it has to do with the fact that R-44 is a negative polarity powered unit, while almost everything else that we typically use is powered using positive polarity?
Title: Re: Aerco MP-2 preamp - Part 2
Post by: page on September 26, 2012, 10:48:18 AM
I wonder if it has to do with the fact that R-44 is a negative polarity powered unit, while almost everything else that we typically use is powered using positive polarity?

that should only affect sharing a battery.
Title: Re: Aerco MP-2 preamp - Part 2
Post by: Gutbucket on September 26, 2012, 10:59:54 AM
Same thing happened to Gutbucket a few weeks ago when he used my Aerco with his R44. 

Thanks for lending me the pre, Dan.

I was running it into the DR-680 actually (MG M94/MV692 > Areco > DR-680 line-in ch5/6).  I suspect the problem was gain staging between the two, but I'm not certain.  It was the only time I've run the Aerco or really taken a good look at one so I'm not that familiar with it.  It was a pretty quick setup and roll situation and I simply set the Aerco gain right in the middle of it's adjustment range and then adjusted line-input gain on the 680 to get decent levels.  I didn't record what that gain setting on the 680 was, but it was somewhere below the middle '0' setting, but not by a lot (DR-680's gain trim adjustment is +/- from 0).  I assumed that would be a safe setting on both devices, but the resulting recording has some not overly severe but audible distortion, and the visual display of the waveform showed uniformly compressed/flattened peaks at a specific level well below 0 DBFS which looked similar to classic brickwall behaviour.  Could be heavy saturation of the Aerco's output transformers I suppose, but I don't own any transformer output preamps so I'm not sure.

[edit- I also wondered about the state of charge of the battery in the Aerco, but Spyder assured me that wasn't the problem.  This was on-stage for an instrumental jazz trio, amplified but no PA, neither overly quiet nor crushingly loud] 
Title: Re: Aerco MP-2 preamp - Part 2
Post by: acidjack on September 26, 2012, 11:07:57 AM
I run Aerco>R-44 (ocm) regularly with no issues. Usually set the 44 to 9 o'clock and run the Aerco at 10 or 20dB gain. Most of my stuff is loud.
Title: Re: Aerco MP-2 preamp - Part 2
Post by: cashandkerouac on September 26, 2012, 04:47:35 PM
i also run my Aerco MP-2 into an R-44 sometimes and have never had a problem.  you have to set the gain on the R-44 first, then set the level on the Aerco.  it may seem counter-intuitive, but it works.  i always start with the outer and inner knobs of the R-44 set to 12 Noon and then will adjust the levels on the Aerco.  configured with the R-44 the levels on the Aerco are always extremely low. 

someone else in this thread recommended not using the Aerco with the R-44 (since it has the Oade OCM), and that is a perfectly viable strategy.  i don't think you sacrifice anything going that route, as the R-44 OCM sounds great without the use of an external pre.  my use of the Aerco with the R-44 is primarily for the "flavor" of the Aerco.  i suppose it's not terribly different from putting grated parmesan cheese on your pasta.  the pasta doesn't necessarily need it to taste good, but you may just prefer it with cheese.  in my opinion Jerry Chamkis makes great cheese!!!   ;D       
Title: Re: Aerco MP-2 preamp - Part 2
Post by: Gutbucket on September 26, 2012, 04:52:39 PM
I run Aerco>R-44 (ocm) regularly with no issues. Usually set the 44 to 9 o'clock and run the Aerco at 10 or 20dB gain. Most of my stuff is loud.

To aproximately what clock position does the gain knob point for +10-20dB?
Title: Re: Aerco MP-2 preamp - Part 2
Post by: cashandkerouac on September 26, 2012, 05:36:51 PM
I run Aerco>R-44 (ocm) regularly with no issues. Usually set the 44 to 9 o'clock and run the Aerco at 10 or 20dB gain. Most of my stuff is loud.

To aproximately what clock position does the gain knob point for +10-20dB?

on my unit i have a continuous gain knob (no steps).  i always set pre-amp gain agianst levels on the recorder.  the "marker" on the gain knob of the Aerco is in a random location (in other words at "0" gain the knob marker does not point to 12 Noon) so i never have any idea how many db of gain are being provided by the Aerco.  however, i do know for sure that I have never opened up the gain on the Aerco past 50%.  and when using it with the R-44 i'm probably only using 10% of available gain from the Aerco.  gain knobs on the R-44 are almost always set to 12 Noon and levels peak at around -6 db on the R-44. 
Title: Re: Aerco MP-2 preamp - Part 2
Post by: Gutbucket on September 26, 2012, 10:17:31 PM
Assuming the center digital trim knob is kept at 12:00, the R-44's input sensitivity is adjustable from +4 to -56dBu.  With the outer knob at 12:00 its -26dBu.

The DR-680 input stage is switchable between Mic & Line sensitivity.  Switched to Line-in mode it's range is +24 to -27.5dBu, and set at 12:00 its +4dBu.  The 680 line-in should be able to take a really hot input, though I haven't tested it with anything super hot.

I dialed the 680 back a bit from 12:00 so I probably had set to ~ +10dBu or so.  That was after setting the Aerco to the dead center of it's gain range, which was higher than Spyder's normal setting (at least what it was set to when he handed it to me) but still well within the comfort zone of the 680.  I probably should have left the Aerco set where Spyder typically uses it into his M10, but the whole idea of borrowing it was to checkout the influence of its output transformers on my Gefells so I figured mid-way on the dial would be safe to get that touch of trafo color.
 
This all leads me to assume it was the Aerco was doing the distorting in my case for whatever reason. [shrug]
Title: Re: Aerco MP-2 preamp - Part 2
Post by: it-goes-to-eleven on September 27, 2012, 09:26:49 AM
but the whole idea of borrowing it was to checkout the influence of its output transformers on my Gefells so I figured mid-way on the dial would be safe to get that touch of trafo color.
 
This all leads me to assume it was the Aerco was doing the distorting in my case for whatever reason.

The transformers in the AERCO are input, not output.

Based on experiences recording dino jr, and high signal level bench testing, it is unlikely the aerco distorted. That is not to suggest that it won't if turned up too high, and that may have been what happened.  But I think your recorder would clip way before the aerco.

This is another example of why I prefer stepped pots or switches for gain control.
Title: Re: Aerco MP-2 preamp - Part 2
Post by: Gutbucket on September 27, 2012, 11:20:13 AM
I'll have to check the 680 to determine it's real overload point as opposed to the published specs, but I've run other signals line-in at similar input gain settings without issue, so I sort of doubt that the recorder input stage was the culprit but won't rule it out.

Maybe the batteries in the Aerco actually were less charged than suspected, and setting it for more gain than Spyder typically uses, though well within is capability with a full charge, may have pushed it past the available supply rail voltage with a less than fully charged battery.   Just guessing though.
Title: Re: Aerco MP-2 preamp - Part 2
Post by: aaronji on September 27, 2012, 11:31:11 AM
Per Jerry, the output of the Aerco can handle 20 V peak-to-peak.  I am not exactly sure what the sensitivity of the Gefells is (maybe 14 mV/Pa), but you'd have to add a lot of gain to a fairly loud signal to clip it.  At 25 dB gain (that's half of the Aerco's range), you'd need SPLs around 124 dB to hit that point (assuming that 14 mV/Pa is correct).  Like it-goes-to-eleven mentioned, I have recorded very loud music (Tortoise) with very sensitive mics (40 mV/Pa) with no problems.  Not much gain on the Aerco there, though.

Also worth bearing in mind that the gain markings on the Aerco sticker are for the switches; those numbers don't relate to the detented variable pots...
Title: Re: Aerco MP-2 preamp - Part 2
Post by: Gutbucket on September 27, 2012, 12:34:02 PM
I am not exactly sure what the sensitivity of the Gefells is (maybe 14 mV/Pa)

The M94s caps have a sensitivity of 12mv/Pa, so even slighlty less than that (no pad or LPF engaged on the MV692s BTW).  The cause of the distortion is mostly speculation on my part at this point really, but thanks to everyone here for the input on figuring it out.  You regular users must be familiar with the Aerco's behavior when it runs low on juice, no?  What's the typical result in that case?

I'll try and post some waveform images if I get the time.  I should be able to also post comparative waveform images of  the same mics going direct into the 680 and through the V3, same band and on-stage setup, different nights.
Title: Re: Aerco MP-2 preamp - Part 2
Post by: acidjack on September 27, 2012, 01:19:10 PM
I run Aerco>R-44 (ocm) regularly with no issues. Usually set the 44 to 9 o'clock and run the Aerco at 10 or 20dB gain. Most of my stuff is loud.

To aproximately what clock position does the gain knob point for +10-20dB?

On mine it's marked.... I can't recall exactly, but it's clearly labeled. It's a stepped-gain unit, mine at least.
Title: Re: Aerco MP-2 preamp - Part 2
Post by: cashandkerouac on September 27, 2012, 02:01:51 PM
I am not exactly sure what the sensitivity of the Gefells is (maybe 14 mV/Pa)

The M94s caps have a sensitivity of 12mv/Pa, so even slighlty less than that (no pad or LPF engaged on the MV692s BTW).  The cause of the distortion is mostly speculation on my part at this point really, but thanks to everyone here for the input on figuring it out. You regular users must be familiar with the Aerco's behavior when it runs low on juice, no?  What's the typical result in that case?

I'll try and post some waveform images if I get the time.  I should be able to also post comparative waveform images of  the same mics going direct into the 680 and through the V3, same band and on-stage setup, different nights.

my unit has an internal lithium-ion rechargeable battery and i've never been in a situation where it was running low on juice.  if i'm at a festival i power the Aerco with a Tekkeon 3450 set to 7.4v* and i can easily run it all weekend without issue.  if i'm just going to a regular show that is about 3-4 hours in length i just use the internal charge on the battery and i've never come close to running out of juice.  so, in a nutshell, i have no idea how it behaves when the battery is low.... and that's a beautiful thing! 

*i've powered the Aerco with 9v and 7.4v with no audible difference in quality.  Jerry even confirmed that the unit will function just fine with power anywhere betwen 7.4v and 12.v.
         
Title: Re: Aerco MP-2 preamp - Part 2
Post by: Myco on September 27, 2012, 02:03:22 PM
Per Jerry, the output of the Aerco can handle 20 V peak-to-peak.  I am not exactly sure what the sensitivity of the Gefells is (maybe 14 mV/Pa), but you'd have to add a lot of gain to a fairly loud signal to clip it.  At 25 dB gain (that's half of the Aerco's range), you'd need SPLs around 124 dB to hit that point (assuming that 14 mV/Pa is correct).  Like it-goes-to-eleven mentioned, I have recorded very loud music (Tortoise) with very sensitive mics (40 mV/Pa) with no problems.  Not much gain on the Aerco there, though.

Also worth bearing in mind that the gain markings on the Aerco sticker are for the switches; those numbers don't relate to the detented variable pots...

On a non-scientific note, I have used my same Gefell > Aerco setup going into my DR-680 (using the exact same levels as the R-44) and it did not distort on the 680. On the R-44, I'd have had distortion, so this is what leads me to believe it has something to do with the R-44's inputs, rather than with the Aerco's outputs.
Title: Re: Aerco MP-2 preamp - Part 2
Post by: aaronji on September 27, 2012, 04:55:28 PM
On mine it's marked.... I can't recall exactly, but it's clearly labeled. It's a stepped-gain unit, mine at least.

Those labels are for the Aercos with gain switches; the numbers don't match up for the ones with variable pots...
Title: Re: Aerco MP-2 preamp - Part 2
Post by: acidjack on October 01, 2012, 11:06:23 AM
On mine it's marked.... I can't recall exactly, but it's clearly labeled. It's a stepped-gain unit, mine at least.

Those labels are for the Aercos with gain switches; the numbers don't match up for the ones with variable pots...

Yeah, I gathered that.  It would seem that if you have variable gain, you have to be a bit more careful about how hot you're running it.

That said, I still can't see how people are overloading an R-44 with one unless they're running the Aerco way too hot.  One of my favorite things about the 44 is being able to easily drop the digital input gain with that outer clickwheel on each level control.  Running it at 9 o'clock with the Aerco (which is lower than I do with other analog inputs) I have never had an issue.   With my mics I'm usually running at least one or two positions higher, depending on the mic and situation.
Title: Re: Aerco MP-2 preamp - Part 2
Post by: hi and lo on October 01, 2012, 03:05:03 PM
How do the 'clickies' work on the R-44? Is attenuation applied if they're turned to their lowest setting (i.e. no signal is passed)?
Title: Re: Aerco MP-2 preamp - Part 2
Post by: acidjack on October 01, 2012, 03:29:24 PM
How do the 'clickies' work on the R-44? Is attenuation applied if they're turned to their lowest setting (i.e. no signal is passed)?

It will still register levels if the clickies are all the way down; the clickies, as I understand them, change the sensitivity of the deck's inputs.  You know that I'm completely non-knowledgable about the electrical engineering aspects of this, but when the clicky is all the way down, the sensitivity reads as +4.  As you turn it up, it moves into negative numbers.  I don't know why it goes from positive to negative as you make it more sensitive, but I am sure you do.

The analog in the 680 is the "MIC" versus "LINE" setting on the top of the unit; the -44 just implements it more incrementally.  The clickwheel sensitivity settings are one of the features I like a lot more about the R-44 (and the meters).
Title: Re: Aerco MP-2 preamp - Part 2
Post by: drewski1986 on January 12, 2013, 07:57:33 AM
Has anyone used the 3.5mm headphone jack as a line out to a small recorder?  If so, was there any noticeable noise associated with this output jack compared to the rca outs?  Thanks for any information on this.
Title: Re: Aerco MP-2 preamp - Part 2
Post by: it-goes-to-eleven on January 12, 2013, 09:54:47 AM
I have used it.  It works fine. It connects to the same circuit as the RCA's.  Assuming your plug is not strained, etc, there should be no issue.

I tend to use the RCA's because I consider them more robust, but that is debatable and very dependent on the particular cable used.

For anyone interested who may not have seen it, I have an AERCO for sale in the yard.

Edit: there is a performance consideration.  The RCA outputs allow you to keep both channels more isolated, each in its own shield, potentially reducing crosstalk.  Most 1/8" jack cables don't do that, and the off the shield stuff is often poorly shielded.
Title: Re: Aerco MP-2 preamp - Part 2
Post by: cashandkerouac on January 28, 2013, 11:59:27 AM
I have used it.  It works fine. It connects to the same circuit as the RCA's.  Assuming your plug is not strained, etc, there should be no issue.

I tend to use the RCA's because I consider them more robust, but that is debatable and very dependent on the particular cable used.

For anyone interested who may not have seen it, I have an AERCO for sale in the yard.

Edit: there is a performance consideration.  The RCA outputs allow you to keep both channels more isolated, each in its own shield, potentially reducing crosstalk.  Most 1/8" jack cables don't do that, and the off the shield stuff is often poorly shielded.

i have also used the mini jack with good results, but prefer using the RCA jacks.  the MP-2 rocks!!! and Jerry is awesome do deal with!!!
Title: Re: Aerco MP-2 preamp - Part 2
Post by: Todd R on January 28, 2013, 12:33:53 PM
I've used the mini out, and now I wish I could remember what show it was for (so I could correct it).  In doing some testing with my Aerco this weekend, I realized that the mini out is wired backwards for the typical stereo minijack -- left and right channel are swapped (meaning technically, the tip is the right signal and ring is the left signal on the jack).

At least it is on my Aerco, not sure if this is the standard Jerry used for all the Aerco's.
Title: Re: Aerco MP-2 preamp - Part 2
Post by: cashandkerouac on January 30, 2013, 02:41:10 PM
^^^ my L-R channels are the same whether i use the RCA outs or the mini out.
Title: Re: Aerco MP-2 preamp - Part 2
Post by: drewski1986 on February 01, 2013, 04:51:57 PM
Thanks for the replies.  For the record, my L-R are the same also whether using rca's or mini jack out.
Title: Re: Aerco MP-2 preamp - Part 2
Post by: jbell on March 02, 2013, 11:58:23 AM
Anyone using rechargeable 9v's in their MP-2??  I'm curious what the run times are with rechargeable batteries.  Thanks
Title: Re: Aerco MP-2 preamp - Part 2
Post by: markrsmith on March 02, 2013, 02:41:35 PM
I don't think they fit.  That is why I did not buy one.  I emailed Jerry about it, and he said they did not fit.  For what ever reason, I do not know.
Title: Re: Aerco MP-2 preamp - Part 2
Post by: larrysellers on March 02, 2013, 04:16:10 PM
They fit fine in my Aerco. I got around 4 hours going mk4->cable->pfa-> aerco but I am sure it could have ran longer.
Title: Re: Aerco MP-2 preamp - Part 2
Post by: jbell on March 02, 2013, 04:18:12 PM
Thanks!  What brand did you use??

They fit fine in my Aerco. I got around 4 hours going mk4->cable->pfa-> aerco but I am sure it could have ran longer.
Title: Re: Aerco MP-2 preamp - Part 2
Post by: larrysellers on March 02, 2013, 04:28:50 PM
POWEREX - Make sure they are marked 9.6v. I don't know if the Aerco is as picky as the nbox. It may run fine with regular 9v(8.4) rechargables but I have never tried it.
Title: Re: Aerco MP-2 preamp - Part 2
Post by: F.O.Bean on March 03, 2013, 12:01:31 AM
Anyone using rechargeable 9v's in their MP-2??  I'm curious what the run times are with rechargeable batteries.  Thanks

Congrats on the Aerco buddy ;) When/where did u score it? I ran one for awhile WAY back in the day
Title: Re: Aerco MP-2 preamp - Part 2
Post by: jbell on March 03, 2013, 09:27:52 AM
Grabbed the one Brian was selling in the YS!

Anyone using rechargeable 9v's in their MP-2??  I'm curious what the run times are with rechargeable batteries.  Thanks

Congrats on the Aerco buddy ;) When/where did u score it? I ran one for awhile WAY back in the day
Title: Re: Aerco MP-2 preamp - Part 2
Post by: audBall on June 01, 2013, 07:39:10 PM
So, I took the (impulse) plunge and snagged a MP2 that was on eBay, of all places. It's unlike any type I've ever seen before...no gain knobs. It appears to be in fairly unused condition with very little wear at all. The gain range is 20-50db and is selected via internal selector switches that can be adjusted with a jeweler's screwdriver through the RCA outputs. I didn't realize until I completed the sale that is was from Jerry Bruck of Posthorn. I have a Tekkeon knock-off that has a handful of power connectors and one fit the unit quite well and it powered right up. Looking forward to giving it a test-drive here soon.

There are graphs included that are apparently from Vark Audio and are dated 9/26/91, so it's at least that old. Not a bad GD show that night.  ;)

Here are some pics:

(http://i14.photobucket.com/albums/a319/audioballer/Mics/MP2-3_zpse27feb3c.jpg)

(http://i14.photobucket.com/albums/a319/audioballer/Mics/MP2-2_zpsf1bfe0c9.jpg)

(http://i14.photobucket.com/albums/a319/audioballer/Mics/MP2-1_zps30c30deb.jpg)
Title: Re: Aerco MP-2 preamp - Part 2
Post by: larrysellers on June 01, 2013, 09:13:46 PM
Nice preamp.
Title: Re: Aerco MP-2 preamp - Part 2
Post by: Marshall7 on June 01, 2013, 11:28:48 PM
"The gain range is 20-50db and is selected via internal selector switches that can be adjusted with a jeweler's screwdriver through the RCA outputs."

Yeah, that's handy ::)
Title: Re: Aerco MP-2 preamp - Part 2
Post by: noahbickart on June 02, 2013, 02:52:39 AM
"The gain range is 20-50db and is selected via internal selector switches that can be adjusted with a jeweler's screwdriver through the RCA outputs."

Yeah, that's handy ::)

As long as the a>d converter has adjustable gain, what's the problem?
Title: Re: Aerco MP-2 preamp - Part 2
Post by: page on June 02, 2013, 09:46:22 AM
"The gain range is 20-50db and is selected via internal selector switches that can be adjusted with a jeweler's screwdriver through the RCA outputs."

Yeah, that's handy ::)

As long as the a>d converter has adjustable gain, what's the problem?

clipping the output of the aerco (or the input of your ADC further down the line) is the one issue I see. If you have a reasonably close idea of how loud it's going to be then it doesn't matter, but if you have dynamic material or will be in a situation which is unfamiliar, then it could be an issue.
Title: Re: Aerco MP-2 preamp - Part 2
Post by: audBall on June 02, 2013, 12:06:47 PM
Yeah, that's handy ::)

Actually, it is for me. I know my mics, my recorder and the situations I record in. I have been taping with fixed gain settings on the tinybox for a while now and it works just fine. But thanks for the input.

*3 snaps in a Z-formation*
Title: Re: Aerco MP-2 preamp - Part 2
Post by: Marshall7 on June 02, 2013, 01:54:35 PM
Well, that's just wonderful for YOU.  But for everyone in every case...not so much. 
Title: Re: Aerco MP-2 preamp - Part 2
Post by: larrysellers on June 02, 2013, 04:37:33 PM
My comment wasn't exactly making a contribution to this thread so I will take the mulligan. I own several fixed gain preamps and prefer them for how I record.
Title: Re: Aerco MP-2 preamp - Part 2
Post by: page on June 02, 2013, 05:20:57 PM
I wonder what transformers it uses.
Title: Re: Aerco MP-2 preamp - Part 2
Post by: audBall on June 02, 2013, 06:22:18 PM
The documentation provided states "Jensen (Reichenbach)" which seems ambiguous. Did one acquire the other at one point?
Title: Re: Aerco MP-2 preamp - Part 2
Post by: hi and lo on June 02, 2013, 06:45:38 PM
The documentation provided states "Jensen (Reichenbach)" which seems ambiguous. Did one acquire the other at one point?

I believe that Reichenbach was at one point an OEM manufacturer for Jensen.

Yeah, that's handy ::)

Actually, it is for me. I know my mics, my recorder and the situations I record in. I have been taping with fixed gain settings on the tinybox for a while now and it works just fine. But thanks for the input.

*3 snaps in a Z-formation*
Well, that's just wonderful for YOU.  But for everyone in every case...not so much. 

Not sure why this devolved into a snarkfest, but I much prefer fixed gain (or rather, not easily adjustable) if I have a good understanding of the gear and recording conditions I'll be in. Every knob, switch, or additional feature increases the likelihood of accidents or equipment failure, especially when working in the field. External gain knobs obviously have a purpose, but the lack of them on this unit is anything but poor design.


As long as the a>d converter has adjustable gain, what's the problem?

The purpose of an A/D isn't to provide gain. Althought there are all-in-one units that combine the functions of a preamp and a/d converter, a stand-alone A/D converter has an input sensitivity setting which is not meant to be used as on-the-fly gain. Its purpose is to calibrate the input sensitivity of the A/D so that it will visually clip 3-6 dB before the mic preamp.
Title: Re: Aerco MP-2 preamp - Part 2
Post by: it-goes-to-eleven on June 02, 2013, 09:18:32 PM
Tiny pots like those in the picture often aren't designed for lots of use or strain.  They might be prone to wearing out.

I'm not sure when Jerry started using stepped grayhill pots, but they are very robust and well-positioned.  I have some shows where gain changes must occur due to non-amplified encores, so the ability to change gain is an essential feature for me. Ideally that happens via a knob that can be rotated a certain amount in complete darkness, by feel alone.
Title: Re: Aerco MP-2 preamp - Part 2
Post by: scb on June 03, 2013, 09:53:57 AM
*3 snaps in a Z-formation*

Thank you for the In Living Color laugh
Title: Re: Aerco MP-2 preamp - Part 2
Post by: spyder9 on June 03, 2013, 10:35:06 AM
Welcome to Team Aerco, Horus.   ;D
Title: Re: Aerco MP-2 preamp - Part 2
Post by: audBall on June 03, 2013, 12:18:19 PM
Thanks for all the input guys.

As 11 mentioned, my only real concern is the durability of the switches over time. Rarely do I need anything other than 20-30db of gain for the situations I record in so I can't imagine they're going to get worked too hard. And if something ever happens I'll just contact Jerry and get the thing fixed...or see if he can mod it to have external knobs. Basically, I think of the thing as a tiny "brick" (m148) and can always adjust the input level of the m10 if needed. Unfortunately, I don't get to record in acoustic settings these days - jazz and whatnot - so massive dynamic changes are rare for me.
Title: Re: Aerco MP-2 preamp - Part 2
Post by: carlbeck on February 21, 2014, 04:55:26 PM
Figured I should say hi since I just unboxed my new to me Aerco!
Title: Re: Aerco MP-2 preamp - Part 2
Post by: axomxa on February 21, 2014, 05:56:09 PM
Nice Carl.  I guess you are now "all the way back"  ;D
Title: Re: Aerco MP-2 preamp - Part 2
Post by: carlbeck on February 21, 2014, 06:35:35 PM
Nice Carl.  I guess you are now "all the way back"  ;D
Hmmmm, maybe. I should wait until my 63's arrive & the C34 is fixed to be sure  >:D
Title: Re: Aerco MP-2 preamp - Part 2
Post by: deadheadcorey on April 01, 2014, 05:25:20 PM
can I run mics > mp-2 > r-09?
Title: Re: Aerco MP-2 preamp - Part 2
Post by: larrysellers on April 01, 2014, 05:29:15 PM
Yes, you would just need an rca to 3.5mm cable.

can I run mics > mp-2 > r-09?
Title: Re: Aerco MP-2 preamp - Part 2
Post by: yug du nord on April 01, 2014, 06:11:41 PM
Yes, you would just need an rca to 3.5mm cable.

can I run mics > mp-2 > r-09?

or just a 3.5mm > 3.5mm TRS cable if the aerco has a 3.5mm output.
Title: Re: Aerco MP-2 preamp - Part 2
Post by: deadheadcorey on April 01, 2014, 06:42:09 PM
Yes, you would just need an rca to 3.5mm cable.

can I run mics > mp-2 > r-09?

or just a 3.5mm > 3.5mm TRS cable if the aerco has a 3.5mm output.

okay same as I would do with the ua-5
Title: Re: Aerco MP-2 preamp - Part 2
Post by: cashandkerouac on April 01, 2014, 06:42:47 PM
Yes, you would just need an rca to 3.5mm cable.

can I run mics > mp-2 > r-09?

or just a 3.5mm > 3.5mm TRS cable if the aerco has a 3.5mm output.

i have used the RCA outs and 3.5mm stereo out with similar success.  i'm pretty sure the RCA outs send a slightly hotter signal, but that's the only difference that i'm aware of.   
Title: Re: Aerco MP-2 preamp - Part 2
Post by: gormenghast on April 14, 2014, 01:57:01 PM
 :yahoo:
Title: Re: Aerco MP-2 preamp - Part 2
Post by: audBall on April 14, 2014, 03:08:30 PM
That's cherry!  8)
Title: Re: Aerco MP-2 preamp - Part 2
Post by: spyder9 on April 14, 2014, 03:16:41 PM
What Brand did you use?  Part #?  I need you repaint mine.  Thanks for sharing.

Title: Re: Aerco MP-2 preamp - Part 2
Post by: gormenghast on April 14, 2014, 03:21:54 PM
What Brand did you use?  Part #?  I need you repaint mine.  Thanks for sharing.

It's a new pre made by Jerry at Aerco.  He sent me an email and said I could have my choice of color.  I didn't really care, but chose red.

"Your preamp is getting close!  The die-cast box I use is now available in colors. Beside the basic black, you can have a factory paint job in yellow, orange, red, green, or gray if you prefer."
Title: Re: Aerco MP-2 preamp - Part 2
Post by: aaronji on April 14, 2014, 03:43:20 PM
i have used the RCA outs and 3.5mm stereo out with similar success.  i'm pretty sure the RCA outs send a slightly hotter signal, but that's the only difference that i'm aware of.

I have also used both and the difference is indeed pretty slight.  I asked Jerry about this once and he replied that they were the same (but that you should carefully monitor the output from the 1/8" as they are the least reliable connectors in his opinion).  You can use both simultaneously too (I usually use the RCAs, but once I ran 1/8" > M10 and RCA > R-44 for a comp, which it suddenly occurs to me I never posted)...

gormenghast: what does the switch do?  Is it off/+20 dB?  Or 0 dB/+20 dB with the standard power switch on the back?  Also, did you do the paint job or did Jerry?
Title: Re: Aerco MP-2 preamp - Part 2
Post by: gormenghast on April 14, 2014, 04:32:01 PM
The pre is fixed at 20.  The switch is for off/on. 

Same exact size as the Nbox--most likely the same box.
Title: Re: Aerco MP-2 preamp - Part 2
Post by: aaronji on April 14, 2014, 04:43:19 PM
Interesting.  It definitely makes for a less busy front panel.  One thing I like about the Aerco is that Jerry will build it how you want it, if possible.  I have seen a lot of different variants at this point...
Title: Re: Aerco MP-2 preamp - Part 2
Post by: hi and lo on April 14, 2014, 04:57:53 PM
What Brand did you use?  Part #?  I need you repaint mine.  Thanks for sharing.

For reference, it's a Hammond 1590BB. Comes in Black, Cobalt Blue, Green, Light Gray, Orange, Purple, Red, and Yellow.

http://www.hammondmfg.com/dwg_SBVer.htm
Title: Re: Aerco MP-2 preamp - Part 2
Post by: twoodruff on April 21, 2014, 12:28:11 PM
What cables will I need to go:

From mics to mp2 (I imagine just xlr)
From mp2 to hsp82 (xlr inputs)
From mp2 to sony pcm-m10
Title: Re: Aerco MP-2 preamp - Part 2
Post by: aaronji on April 21, 2014, 01:33:29 PM
The "standard" Aerco has XLR inputs and both RCA and 1/8" outputs. So XLR cables between mics and pre (the way I run mine, I prefer stubbies at the pre end). Either RCA to XLR  or 1/8" to XLR for the HS-P82 and either RCA to 1/8" or 1/8" to 1/8" for the M10...
Title: Re: Aerco MP-2 preamp - Part 2
Post by: deadheadcorey on April 21, 2014, 08:00:44 PM
so who is the one that bought larry's mp-2 out of the yardsale?
Title: Re: Aerco MP-2 preamp - Part 2
Post by: twoodruff on April 22, 2014, 01:00:26 AM
so who is the one that bought larry's mp-2 out of the yardsale?

I traded for larry's who he got from me who I got from ted.
Title: Re: Aerco MP-2 preamp - Part 2
Post by: deadheadcorey on April 22, 2014, 02:42:46 AM
so who is the one that bought larry's mp-2 out of the yardsale?

I traded for larry's who he got from me who I got from ted.

nice i was gonna pull the trigger on it, but i am just so tight for cash right now i couldnt do it...  though in the near future i am gonna get one
Title: Re: Aerco MP-2 preamp - Part 2
Post by: it-goes-to-eleven on April 22, 2014, 09:56:50 AM
I traded for larry's who he got from me who I got from ted.

It needs to be like the Stanley Cup - each owner name engraved on side.
Title: Re: Aerco MP-2 preamp - Part 2
Post by: tgakidis on April 22, 2014, 06:03:29 PM
I traded for larry's who he got from me who I got from ted.

It needs to be like the Stanley Cup - each owner name engraved on side.

Ha, I didn't realize that was mine.  I almost bought it back myself!
Title: Re: Aerco MP-2 preamp - Part 2
Post by: cashandkerouac on April 23, 2014, 11:46:15 AM
I traded for larry's who he got from me who I got from ted.

It needs to be like the Stanley Cup - each owner name engraved on side.

Ha, I didn't realize that was mine.  I almost bought it back myself!

add me to the list of people with an itchy trigger finger for that Aerco.  great deal!  i was amazed how long it hung around unclaimed.  the Aerco was the first really good pre-amp that i purchased, and it is still the best one i've owned.  and in addition to it being a superb preamp, Jerry is wonderful and takes excellent care of his customers.
Title: Re: Aerco MP-2 preamp - Part 2
Post by: audBall on December 28, 2014, 11:32:58 PM
I wonder what transformers it uses.

Super late bump on this, Page (and all), but I was bored tonight and decided to take a closer look shining a flashlight down into the MP2 and noticed the transformers are stamped "RE 13K6-C". Not sure what sparked this interest tonight, but I've been reading old posts on TS related to Jensen/Reich transformers and was curious if anyone had a similar model.

Here is the Richenbach link for their 13K6-C:
http://www.technicalaudio.com/pdf/Jensen_Transformers/JE_RE_JT_Mic_Input_Transformers/Reichenbach_RE-13K6-C_mic_input_xfmr.pdf

(I noticed that some of the paperwork included with my Aerco is dated 1992 and the PDF above is dated 1991. This puts me in 4-5th grade when this thing was made, at the very latest.)

and Jensen's 13K6-C:
http://www.jensen-transformers.com/wp-content/uploads/2014/08/jt-13k6-c.pdf

I noticed on a previous page that gormenghast's pre has Jensen JT-MP-CPCA's.

Which kind do you have?
Title: Re: Aerco MP-2 preamp - Part 2
Post by: willndmb on December 29, 2014, 04:29:31 PM
The "standard" Aerco has XLR inputs and both RCA and 1/8" outputs. So XLR cables between mics and pre (the way I run mine, I prefer stubbies at the pre end). Either RCA to XLR  or 1/8" to XLR for the HS-P82 and either RCA to 1/8" or 1/8" to 1/8" for the M10...
are both outs active at once?
Title: Re: Aerco MP-2 preamp - Part 2
Post by: acidjack on December 29, 2014, 05:19:13 PM
The "standard" Aerco has XLR inputs and both RCA and 1/8" outputs. So XLR cables between mics and pre (the way I run mine, I prefer stubbies at the pre end). Either RCA to XLR  or 1/8" to XLR for the HS-P82 and either RCA to 1/8" or 1/8" to 1/8" for the M10...
are both outs active at once?

Yes
Title: Re: Aerco MP-2 preamp - Part 2
Post by: aaronji on December 29, 2014, 07:33:38 PM
I asked Jerry about this once, and he said that there is no problem, and no difference, using both outputs at the same time.  I did this at a show not too long ago, to comp the M10 and R44 line-inputs, but I never posted it.  I figured it wouldn't be of much interest, as they are such different recorders, but I can dig it up if anyone is interested (I think it was DPA2006C > Aerco (RCA) > R44 and DPA2006C > Aerco (1/8") > M10).

EDIT:  Re-reading the thread a bit, apologies for the double post:

I asked Jerry about this once and he replied that they were the same (but that you should carefully monitor the output from the 1/8" as they are the least reliable connectors in his opinion).  You can use both simultaneously too (I usually use the RCAs, but once I ran 1/8" > M10 and RCA > R-44 for a comp, which it suddenly occurs to me I never posted)...
Title: Re: Aerco MP-2 preamp - Part 2
Post by: gormenghast on March 30, 2015, 04:17:22 PM
A not crazy/crazy thought.

Not crazy.  I'm considering sending my Aerco to Jerry and have the battery mod done.  Rechargeable inside and option to use external battery.

Possibly crazy.  I'm also thinking about some other mods.  PFA's inside the box, EN3 connector for input and keep the RCA output and power switch.  Same 20db as I've come accustom to.

Actually combine not crazy and possibly crazy in the current box I have now. 

If you eliminate the XLR jacks that frees some room for the PFA boards.  Plenty of room for the rechargeables and a charging jack.  Basically, the box would look like a NBox but have Aerco guts and use rechargeable batteries.  Looking at the Hammond boxes there is one that is a little bit longer if there needs to be more room, but I prefer this size better. 



 
Title: Re: Aerco MP-2 preamp - Part 2
Post by: gormenghast on March 30, 2015, 05:17:35 PM
What would be the difference if the PFAs were in the box vs out.  They would would still be in the chain.  Wouldn't they?
Title: Re: Aerco MP-2 preamp - Part 2
Post by: jbosco on April 01, 2015, 01:44:48 PM
Skimmed this topic and damn I miss my Aerco!!!
Title: Re: Aerco MP-2 preamp - Part 2
Post by: carlbeck on May 06, 2015, 10:35:13 PM
If anyone is considering selling their Aerco please let me know, it would be the perfect match for my 440's  8)
Title: Re: Aerco MP-2 preamp - Part 2
Post by: tgakidis on May 07, 2015, 10:03:20 AM
If anyone is considering selling their Aerco please let me know, it would be the perfect match for my 440's  8)

You need to add a row to your signature:  Gear I have owned in the past that I wish I still had  :P
Title: Re: Aerco MP-2 preamp - Part 2
Post by: carlbeck on May 07, 2015, 02:46:10 PM
If anyone is considering selling their Aerco please let me know, it would be the perfect match for my 440's  8)

You need to add a row to your signature:  Gear I have owned in the past that I wish I still had  :P

Ha! I kind of already have that line but how was I to know my sluttieness would come back full bore the more I hung out with you?  :P
Title: Re: Aerco MP-2 preamp - Part 2
Post by: macdaddy on May 07, 2015, 02:54:56 PM
If anyone is considering selling their Aerco please let me know, it would be the perfect match for my 440's  8)
???

Title: Re: Aerco MP-2 preamp - Part 2
Post by: carlbeck on May 08, 2015, 12:55:27 PM
So I have read Part 1 & 2, any positive experience with 9v rechargeables? I have a pretty red Aerco coming soon but it doesn't have a jack for external batteries & as much as I don't mind sending it in for repair I also don't want to wait a month or so. I have an email into Jerry to ask if I can do the external jack myself but haven't heard back yet. If I can't do the jack I'll at least want rechargeable 9v's vs buying disposable batteries.
Title: Re: Aerco MP-2 preamp - Part 2
Post by: hi and lo on May 08, 2015, 01:36:43 PM
So I have read Part 1 & 2, any positive experience with 9v rechargeables? I have a pretty red Aerco coming soon but it doesn't have a jack for external batteries & as much as I don't mind sending it in for repair I also don't want to wait a month or so. I have an email into Jerry to ask if I can do the external jack myself but haven't heard back yet. If I can't do the jack I'll at least want rechargeable 9v's vs buying disposable batteries.

Low-Discharge Imedion 9v NiMH rechargable batteries are the shit. They make 8.4v and 9.6v versions, the former having slightly higher capacity but with lower output voltage that might not work for every device. I don't know the particulars of the Aerco, but the decision really has to do with the minimum voltage it will operate at. When the 8.4v versions discharge, they'll spend the majority of their discharge cycle, I believe, somewhere between 7-8vs and drop off below 7 when they're fading. Obviously, the 9.6v versions maintain a slightly higher voltage which makes some devices a lot happier.

I bought 10 9.6v batts about 2.5 years ago for use with Nbox / Reutelhuber devices and have probably run them through 150-200 cycles with no issues. Of the ten, one of them has started to warp a bit, so it's retired, but the rest are still going strong. This is interesting because the Nbox will discharge these to below 1v, which is supposedly horrible treatment for NiMH devices, but they always seem to bounce back.

Definitely don't be afraid of 9v rechargables. You're a real asshole if you continue to dump 9v coppertops in our landfill in 2015.
Title: Re: Aerco MP-2 preamp - Part 2
Post by: gormenghast on May 08, 2015, 02:00:58 PM
So I have read Part 1 & 2, any positive experience with 9v rechargeables? I have a pretty red Aerco coming soon but it doesn't have a jack for external batteries & as much as I don't mind sending it in for repair I also don't want to wait a month or so. I have an email into Jerry to ask if I can do the external jack myself but haven't heard back yet. If I can't do the jack I'll at least want rechargeable 9v's vs buying disposable batteries.

Low-Discharge Imedion 9v NiMH rechargable batteries are the shit. They make 8.4v and 9.6v versions, the former having slightly higher capacity but with lower output voltage that might not work for every device. I don't know the particulars of the Aerco, but the decision really has to do with the minimum voltage it will operate at. When the 8.4v versions discharge, they'll spend the majority of their discharge cycle, I believe, somewhere between 7-8vs and drop off below 7 when they're fading. Obviously, the 9.6v versions maintain a slightly higher voltage which makes some devices a lot happier.

I bought 10 9.6v batts about 2.5 years ago for use with Nbox / Reutelhuber devices and have probably run them through 150-200 cycles with no issues. Of the ten, one of them has started to warp a bit, so it's retired, but the rest are still going strong. This is interesting because the Nbox will discharge these to below 1v, which is supposedly horrible treatment for NiMH devices, but they always seem to bounce back.

Definitely don't be afraid of 9v rechargables. You're a real asshole if you continue to dump 9v coppertops in our landfill in 2015.

Good info on the rechargeables.  Thanks for sharing.

Title: Re: Aerco MP-2 preamp - Part 2
Post by: it-goes-to-eleven on May 08, 2015, 02:05:12 PM
I think you could make an external power connector using a 9v battery connector. You would plug it into one of the three existing battery connectors.  This is based on my recollection that the three 9v's in the AERCO are wired in parallel, but I could be mistaken. Ask Jerry.  And don't mess up the polarity ;)
Title: Re: Aerco MP-2 preamp - Part 2
Post by: carlbeck on May 08, 2015, 02:44:20 PM
I think you could make an external power connector using a 9v battery connector. You would plug it into one of the three existing battery connectors.  This is based on my recollection that the three 9v's in the AERCO are wired in parallel, but I could be mistaken. Ask Jerry.  And don't mess up the polarity ;)

They are wired in parallel & my original thought was maybe if I bought one of the 9v battery tabs that I could wire that to an external jack but I'm not sure if I'd need to do all three tabs to the power jack or not. I emailed him this morning & haven't heard back, hopefully by next week I will.
Title: Re: Aerco MP-2 preamp - Part 2
Post by: hi and lo on May 08, 2015, 03:08:48 PM
I think you could make an external power connector using a 9v battery connector. You would plug it into one of the three existing battery connectors.  This is based on my recollection that the three 9v's in the AERCO are wired in parallel, but I could be mistaken. Ask Jerry.  And don't mess up the polarity ;)

That's a great idea!
Title: Re: Aerco MP-2 preamp - Part 2
Post by: acidjack on May 09, 2015, 12:28:42 PM
I just put an Aerco in the YS. And I agree it'd pair nicely with your 440s.
Title: Re: Aerco MP-2 preamp - Part 2
Post by: Gutbucket on May 12, 2015, 03:59:51 PM
I think you could make an external power connector using a 9v battery connector. You would plug it into one of the three existing battery connectors.  This is based on my recollection that the three 9v's in the AERCO are wired in parallel, but I could be mistaken. Ask Jerry.  And don't mess up the polarity ;)

Remember to wire the 9V battery connector with opposite polarity to how it would normally used (red wire negative, black positive), as it will be taking the place of the the battery output terminals, rather than acting as the opposite gender equipment power input.  I made cables like this for two CA-UGLY preamps to run them for an entire multi day festival on one DVD battery, avoiding the need to change batteries.

Low-Discharge Imedion 9v NiMH rechargable batteries are the shit. [snip]

I bought 10 9.6v batts about 2.5 years ago for use with Nbox / Reutelhuber devices and have probably run them through 150-200 cycles with no issues. Of the ten, one of them has started to warp a bit, so it's retired, but the rest are still going strong. This is interesting because the Nbox will discharge these to below 1v, which is supposedly horrible treatment for NiMH devices, but they always seem to bounce back.

Watch them as they're probably about due for replacement.  Do so before they die during a recording.  My original set of Maha 9.6V batteries eventually died right around that age, after approximately that many cycles, and when they did I screwed up a few recordings before realizing what was going on.  I was checking voltage before and after use and they measured fine, yet I started getting 'low supply voltage' type distortion in the preamps halfway through shows.  Problem was that the batteries would recover enough afterwards to measure like a 'good' although discharged cells (say 7-8V) but under-load in the device they were dropping to something like 4V or less very quickly.  Moral of the story is to measure Voltage immediately after use while the battery is still in the device to determine it's true, sustainable 'under-load' voltage.  Without a load across the battery, or measuring after use, you risk a misleading reading.

No further problems after I realized that and I caught and replaced the second set just as they were beginning to die around the ~3yr old mark before loosing a recording.  By then Maha was making the LSD version of the 9.6V (black/grey case) which also had a higher mAhr rating and that second set lasted longer and retained their charge longer than the original (white case) non-LSD 9.6Vs.

I had one of the original 9.6Vs balloon out all warped and misshapen, called Thomas Distributing to order another, and they immediately shipped a replacement free of charge.
Title: Re: Aerco MP-2 preamp - Part 2
Post by: carlbeck on May 12, 2015, 04:37:13 PM
I think you could make an external power connector using a 9v battery connector. You would plug it into one of the three existing battery connectors.  This is based on my recollection that the three 9v's in the AERCO are wired in parallel, but I could be mistaken. Ask Jerry.  And don't mess up the polarity ;)

Remember to wire the 9V battery connector with opposite polarity to how it would normally used (red wire negative, black positive), as it will be taking the place of the the battery output terminals, rather than acting as the opposite gender equipment power input.  I made cables like this for two CA-UGLY preamps to run them for an entire multi day festival on one DVD battery, avoiding the need to change batteries.

Low-Discharge Imedion 9v NiMH rechargable batteries are the shit. [snip]

I bought 10 9.6v batts about 2.5 years ago for use with Nbox / Reutelhuber devices and have probably run them through 150-200 cycles with no issues. Of the ten, one of them has started to warp a bit, so it's retired, but the rest are still going strong. This is interesting because the Nbox will discharge these to below 1v, which is supposedly horrible treatment for NiMH devices, but they always seem to bounce back.

Watch them as they're probably about due for replacement.  Do so before they die during a recording.  My original set of Maha 9.6V batteries eventually died right around that age, after approximately that many cycles, and when they did I screwed up a few recordings before realizing what was going on.  I was checking voltage before and after use and they measured fine, yet I started getting 'low supply voltage' type distortion in the preamps halfway through shows.  Problem was that the batteries would recover enough afterwards to measure like a 'good' although discharged cells (say 7-8V) but under-load in the device they were dropping to something like 4V or less very quickly.  Moral of the story is to measure Voltage immediately after use while the battery is still in the device to determine it's true, sustainable 'under-load' voltage.  Without a load across the battery, or measuring after use, you risk a misleading reading.

No further problems after I realized that and I caught and replaced the second set just as they were beginning to die around the ~3yr old mark before loosing a recording.  By then Maha was making the LSD version of the 9.6V (black/grey case) which also had a higher mAhr rating and that second set lasted longer and retained their charge longer than the original (white case) non-LSD 9.6Vs.

I had one of the original 9.6Vs balloon out all warped and misshapen, called Thomas Distributing to order another, and they immediately shipped a replacement free of charge.

As always Lee you're a wealth of information, I still haven't heard back from Jerry which is a little disappointing but I'm sure he's just busy. My thought is to use the 9v connector but I'm still not sure if I need to use all three or not. Jerry mentions the power Jack he installs doesn't matter what polarity is used but with my plan is imagine polarity would be a concern. I considered rechargeables but I don't think I could bring the batteries down enough per use/charge cycle to justify. I know they have no memory effect but it seems like I would feel more comfortable charging them before & after each use which would limit lifespan. Is this a correct assumption? It's what I currently do with my Eneloops in the FP24.
Title: Re: Aerco MP-2 preamp - Part 2
Post by: hi and lo on May 12, 2015, 04:40:38 PM
Make sure you have the right contact info. IIRC, he maybe has a bad email published on his website or something? I don't remember the exact issue.
Title: Re: Aerco MP-2 preamp - Part 2
Post by: audBall on May 12, 2015, 04:41:36 PM
Not sure about current models (mine is the 1st configuration, according to Jerry), but it's external jack can accept any polarity. Granted, it was manufactured in ~1992.

edit : Out of curiosity, I asked him how many MP-2's are out there. He said ~150.

woops, had the email backwards. Was looking at old emails. See two posts down for his current email.
Title: Re: Aerco MP-2 preamp - Part 2
Post by: carlbeck on May 12, 2015, 04:43:39 PM
Make sure you have the right contact info. IIRC, he maybe has a bad email published on his website or something? I don't remember the exact issue.

Well then, that may be the problem since I used the link off of his webpage. Anyone have the correct address?
Title: Re: Aerco MP-2 preamp - Part 2
Post by: gormenghast on May 12, 2015, 05:41:26 PM
Make sure you have the right contact info. IIRC, he maybe has a bad email published on his website or something? I don't remember the exact issue.

Well then, that may be the problem since I used the link off of his webpage. Anyone have the correct address?

jerry@jchamkis.com

This is the one I've used recently.  He did have this to say:

"we're struggling with insane network issues"  Last contact was 5/5

Title: Re: Aerco MP-2 preamp - Part 2
Post by: Gutbucket on May 12, 2015, 06:03:02 PM
Should be able to determine if the three 9V connectors are wired parallel or series easily using an ohmmeter.

No problem recharging NiMH 9Vs after only minor drain, I recharge them after each use with no ill effect on run-time or longevity.  If you use the 9.6V version you need the special Maha charger designed specifically for them and not just any charger.  I have the 4-bay version and it's a good charger with a 'smart' routine and separate circuit for each battery.  No switches or controls, just an LED indicator for each bay.  Runs on 12VDC so you can use it in the car or off a deep cycle battery if away from AC power.
Title: Re: Aerco MP-2 preamp - Part 2
Post by: Hypnocracy on May 12, 2015, 06:06:28 PM
Joined the Club about a month ago...picked up topdog's MP-2 in the yard...Course Gain 10db steps on left...Fine Gain 2db steps on right...Internal Li-Ion rechargeable...external power jack too...

Bought it to run AKG CK63's-Naiant Coupling/PFA>MP-2>Tascam DR2D...I've been comparing that setup to the Gefell M200>Portico>DR680 to get a feel for running the DR2D (haven't ran a handheld other than iRiver and Sony D8 Dat days)

(http://i42.photobucket.com/albums/e348/EL_Deano/gear%20bag_zpsdwswzomh.jpg)

I pack two bags (big rig and small) trying to convince myself I'm not losing anything with the small bag...but have yet to run the Gefell's on the Aerco.

Anyone know how long the MP-2 runs off of a MP3450 Tekkeon...I will not drag the Portico to a festival...for multiple reasons.
Title: Re: Aerco MP-2 preamp - Part 2
Post by: Gutbucket on May 12, 2015, 06:29:50 PM
^^
Nice.

Only time I ran my Gefells Aerco>DR-680 was onstage for a jazz trio, but unfortunately the borrowed Aerco had problems and the recording distorted.  It's been fixed since but I haven't had a chance to try it again. 

Love to try the Portico/silk-mode with the Geffs sometime.
Title: Re: Aerco MP-2 preamp - Part 2
Post by: audBall on May 12, 2015, 06:40:20 PM
Anyone know how long the MP-2 runs off of a MP3450 Tekkeon...I will not drag the Portico to a festival...for multiple reasons.

I have a "MP3450" clone and running M2x>nBob>PFA can easily get 8-10 hours with only losing a bar or two on the battery. Never tested it all the way down, but I'd imagine at least 20 hours.
Title: Re: Aerco MP-2 preamp - Part 2
Post by: Hypnocracy on May 12, 2015, 07:38:29 PM
Thanks audball....that would be ideal at Lockn'

Gutbucket...Gefell > Portico Silk in a nice sounding room is magical....check out the "Girl from the North Country" on the Sam Bush Isis Music hall below...Yee Ha factor was somewhat in control on that one...

https://archive.org/details/sbb2015-04-10.Isis_Muisc_Hall_Gefell

If you come back to NC let me know...

Title: Re: Aerco MP-2 preamp - Part 2
Post by: carlbeck on May 12, 2015, 10:44:33 PM
Jerry got back to me this evening & told me exactly what needs to be done to install an external Jack including identifying the proper location when I sent him a picture of the inside. What a great guy, talk about excellent customer service.
Title: Re: Aerco MP-2 preamp - Part 2
Post by: gormenghast on May 13, 2015, 12:45:30 AM
Jerry got back to me this evening & told me exactly what needs to be done to install an external Jack including identifying the proper location when I sent him a picture of the inside. What a great guy, talk about excellent customer service.

He and I chatted about a mod I wanted done to the red Aerco.  But, something came up I'm excited for and am looking toward to.

Good to know you'll get the external jack you want. 
Title: Re: Aerco MP-2 preamp - Part 2
Post by: acidjack on May 23, 2015, 10:04:13 PM
Thanks audball....that would be ideal at Lockn'

Gutbucket...Gefell > Portico Silk in a nice sounding room is magical....check out the "Girl from the North Country" on the Sam Bush Isis Music hall below...Yee Ha factor was somewhat in control on that one...

https://archive.org/details/sbb2015-04-10.Isis_Muisc_Hall_Gefell

If you come back to NC let me know...

Fwiw I briefly owned Gefell 210s.  I really disliked them with the gear I had at the time but loved the Aerco recordings I heard with them. 200s aren't the same thing, but I do find the Aerco is a big help with the rather crispy sounding MBHO KA200s I have.
Title: Re: Aerco MP-2 preamp - Part 2
Post by: Hypnocracy on May 27, 2015, 09:16:49 AM
First outing with the Aerco and Gefell M200's

https://archive.org/download/ep2015-05-16.Pisgah_Gefell/ep20150516_PisgahBrewery_03.mp3

I'm lovin' it....
Title: Re: Aerco MP-2 preamp - Part 2
Post by: spyder9 on May 27, 2015, 10:20:27 AM
First outing with the Aerco and Gefell M200's

https://archive.org/download/ep2015-05-16.Pisgah_Gefell/ep20150516_PisgahBrewery_03.mp3

I'm lovin' it....

+T  Welcome to the team.   :)
Title: Re: Aerco MP-2 preamp - Part 2
Post by: OOK on May 27, 2015, 05:14:20 PM
First outing with the Aerco and Gefell M200's

https://archive.org/download/ep2015-05-16.Pisgah_Gefell/ep20150516_PisgahBrewery_03.mp3

I'm lovin' it....

+T  Welcome to the team.   :)

Of all that is holy...that is........    Phat!!!   I can only imagine what the lossless sounds like.
Title: Re: Aerco MP-2 preamp - Part 2
Post by: spyder9 on May 28, 2015, 04:59:31 PM
Update on Jerry:  The shop got flooded from the storms, so he's been dealing with cleanup. 

He's updating the external power jack on my Aerco, so I reached out to him last night and he replied this morning.  fyi   
Title: Re: Aerco MP-2 preamp - Part 2
Post by: carlbeck on May 28, 2015, 09:28:28 PM
First outing with the Aerco and Gefell M200's

https://archive.org/download/ep2015-05-16.Pisgah_Gefell/ep20150516_PisgahBrewery_03.mp3

I'm lovin' it....

+T  Welcome to the team.   :)

Of all that is holy...that is........    Phat!!!   I can only imagine what the lossless sounds like.

Indeed, that sounds awesome! Have you thought of running a splitter so you can run both the Portico & Aerco with your Gefells since you were concerned about losing the Portico? I did this recently with mine & the FP24 using my MBHO 440's. Since it was an onstage recording the differences were very slight but I plan on trying it in some different venues before I pass judgement.
Title: Re: Aerco MP-2 preamp - Part 2
Post by: OOK on May 29, 2015, 07:39:23 AM
I did this recently with mine & the FP24 using my MBHO 440's. Since it was an onstage recording the differences were very slight but I plan on trying it in some different venues before I pass judgement.

Now you can't drop a comment like that around another mbho owner and get away without saying what those differences were... :P
Title: Re: Aerco MP-2 preamp - Part 2
Post by: carlbeck on May 29, 2015, 10:35:15 AM
I did this recently with mine & the FP24 using my MBHO 440's. Since it was an onstage recording the differences were very slight but I plan on trying it in some different venues before I pass judgement.

Now you can't drop a comment like that around another mbho owner and get away without saying what those differences were... :P

Fair enough, I'll do one step better & put a comparison up later so you can decide for yourself  :)
Title: Re: Aerco MP-2 preamp - Part 2
Post by: carlbeck on May 29, 2015, 10:26:54 PM
I started a new thread with the comp of the Aerco vs the FP for those of you interested, you can decide for yourselves  :)
Title: Re: Aerco MP-2 preamp - Part 2
Post by: audBall on June 29, 2015, 01:21:28 PM
I am thinking about parting with my Aerco (seen here (http://taperssection.com/index.php?topic=123931.msg2041474#msg2041474)) and figured I would check with the team first here. It is in fantastic condition for its age. It was purchased from Jerry Bruck (Posthorn) on eBay back in 2013 and appeared to have never really been used. Mine is somewhat unusual compared to many of the current ones out there. According to Jerry, this preamp is the first MP-2 configuration. Paperwork included showing some tests on the unit are dated 09-1991. The gain adjustments are weird and have to be adjusted with a small jeweler's screwdriver through the RCA jacks, however, I've always left it set in the +20dB setting, effectively treating it as a fixed preamp. There is a small 1" SYF metal sticker on top of the unit now (not pictured). It's actually much cleaner looking on the outside than what's portrayed with using the flash in those pics. When I contacted Jerry about info this preamp and the possibility of replacing the parts, this is what he said:

-
That is indeed the very first configuration, the idea was to have maximum ruggedness as it was favorexd by news crews because at the time it was the only portable preamp that would power the Neuman RSM-190i matrix mic which they frequently used. None of the electronics wear or degrade in normal use- one transformer became noisy when it was immersed in water. Those transformers have spectacular performance but apparently imperfect potting. The switches are a nuisance if you change gain a lot but should be well suited to your mode of use- they are industrial grade and should last essentially forever. Connectors are always prone to wear but the Neutrik XLRs should last for many thousands of insertions / removals. The RCA connectors are more prone to wear but if you're not experiencing any problems there is no benefit in replacing them.  The 3.5 mm stereo connector is never reliable for serious use and is just there for a quick check with a pair of headphones.  With all that said, never hesitate to request service or advice- I take vicarious pleasure from your successful recordings.  :-)) 
-

The transformers are stamped "RE 13K6-C". Here's a link (http://www.technicalaudio.com/pdf/Jensen_Transformers/JE_RE_JT_Mic_Input_Transformers/Reichenbach_RE-13K6-C_mic_input_xfmr.pdf) to the Reichenbach specs for them.

I'd be looking to get exactly what I paid, $525 shipped. If interested, let me know.  SOLD
Title: Re: Aerco MP-2 preamp - Part 2
Post by: Hypnocracy on July 28, 2015, 07:43:20 PM
Gefell M200>Aerco MP2>Tascam DR2d

https://soundcloud.com/hypnocracy/rosalee-chris-robinson-brotherhood-live-2015-07-24

Lovin' It!

Quote
The 3.5 mm stereo connector is never reliable for serious use and is just there for a quick check with a pair of headphones.

I've heard noise from using the mini stereo out...rough movements...But since it was going to the DR2d I never considered the mini output on the Aerco to be suspect any more than the mini stereo recorder input...

Team Members do you go RCA > 1/8 Stereo?
Title: Re: Aerco MP-2 preamp - Part 2
Post by: spyder9 on July 29, 2015, 10:46:24 AM
Gefell M200>Aerco MP2>Tascam DR2d

https://soundcloud.com/hypnocracy/rosalee-chris-robinson-brotherhood-live-2015-07-24

Lovin' It!

Quote
The 3.5 mm stereo connector is never reliable for serious use and is just there for a quick check with a pair of headphones.

I've heard noise from using the mini stereo out...rough movements...But since it was going to the DR2d I never considered the mini output on the Aerco to be suspect any more than the mini stereo recorder input...

Team Members do you go RCA > 1/8 Stereo?

Yes, since day 1.  That 1/8 out is NOT a clean line-out.  As Jerry said, it was intended for headphones.  A good-ole-fashion Y cable from Ratshack or a custom jobbie from Ted Gakadis, has always been the best solution for me.  I've owned & operated my Aerco for 10 years.
Title: Re: Aerco MP-2 preamp - Part 2
Post by: aaronji on July 29, 2015, 04:34:45 PM
I would also recommend the RCA outs.  For my bag set-up, I have found that right angle RCAs work particularly well.  For the record, though, I have run the 1/8" out a couple of times and it sounded fine...
Title: Re: Aerco MP-2 preamp - Part 2
Post by: Hypnocracy on July 29, 2015, 08:37:09 PM
Yeah...I've had it out for three shows and ran just Mini out with no problems...message sent to Ted...need to get that and the latching power cable pigtail I have tied to a Tekkeon for Lockn'
Title: Re: Aerco MP-2 preamp - Part 2
Post by: easy jim on July 29, 2015, 11:01:20 PM
I've never had problems with the mini output on my Aerco, though the channels are inverted from the RCA outputs.
Title: Re: Aerco MP-2 preamp - Part 2
Post by: raoulduke on September 22, 2016, 09:54:36 AM
Does anyone have a current email address for Jerry? I emailed multiple addresses Monday with either no response or delivery errors.

jerry@chamkis.me
jerry@aerco.net
sales@aerco.net  (delivery failed)
jerry@jchamkis.com  (delivery delayed)

For anyone who has an Aerco outfitted with internal lithium poly batteries:
  Any recommendations on where to buy replacement batteries?
  Is it easy to swap them out? Do they snap in or is soldering involved?
Title: Re: Aerco MP-2 preamp - Part 2
Post by: aaronji on September 22, 2016, 10:33:11 AM
Maybe try jchamkis@bga.com.  That is one he has used with me in the past (in addition to jerry@aerco.net and jerry@jchamkis.com).

No idea about the battery, though.  If you find any information about replacing it, please post here!  Mine is still good to go, but I (and others) will surely face that issue at some point...
Title: Re: Aerco MP-2 preamp - Part 2
Post by: it-goes-to-eleven on September 22, 2016, 02:24:15 PM
Jerry sometimes does live sound production for films. Those gigs can have him isolated on site for days. So maybe that is where he is. Or on vacation.
Title: Re: Aerco MP-2 preamp - Part 2
Post by: spyder9 on September 22, 2016, 02:32:04 PM
The jerry@chamkis.me is the last known email address I used to communicate with him.  That was a year ago, August.

I found his phone #.  PM me if interested.
Title: Re: Aerco MP-2 preamp - Part 2
Post by: darby on September 22, 2016, 04:16:10 PM
The jerry@chamkis.me is the last known email address I used to communicate with him.  That was a year ago, August.

I found his phone #.  PM me if interested.

I'm having Jerry work on a box for me now, and that is the email I use to communicate with him.
He is not very fast, and sometimes takes a while to respond.
I'll touch base with him about the replacement battery and see what he suggests.

EDIT: I sent him an email this morning and will post any info he shares with me here.
Title: Re: Aerco MP-2 preamp - Part 2
Post by: spyder9 on September 23, 2016, 10:56:30 AM
The jerry@chamkis.me is the last known email address I used to communicate with him.  That was a year ago, August.

I found his phone #.  PM me if interested.

I'm having Jerry work on a box for me now, and that is the email I use to communicate with him.
He is not very fast, and sometimes takes a while to respond.
I'll touch base with him about the replacement battery and see what he suggests.

Nice!  It would be great hear if he found a good supplier.
Title: Re: Aerco MP-2 preamp - Part 2
Post by: darby on September 25, 2016, 07:06:16 AM
here is what Jerry said:

Hi Michael-
Batteries are available on the web, they're 7.4 volt 900 MaH helicopter batteries. However, since there are two in parallel it's very important to have a matched pair as any difference will reduce the lifetime significantly.

There are also slight variations in size and they're a tight fit so it's tricky to get ones that work well, I have lots of useless leftovers that get re-purposed for in-shop instruments and projects. I sell the matched pairs for $100 / pair plus shipping.

They plug in to a little board at the back of the case, no soldering is required. It is however delicate work in a tight place so I'll do the job if you pay the shipping both ways.

Regards-

Jerry
Title: Re: Aerco MP-2 preamp - Part 2
Post by: aaronji on September 28, 2016, 04:09:03 PM
There is a good picture of a battery that Jerry uses (or, at least, used) in this Yard Sale post (http://taperssection.com/index.php?topic=179045.msg2200886#msg2200886) (the next to last photo). 
Title: Re: Aerco MP-2 preamp - Part 2
Post by: achalsey on November 17, 2017, 06:50:10 PM
One of the knobs on my MP-2 fell off.  Has this happened to anyone before?  Do I just need to find the right screwdriver to tighten the little screws on the knob?  Is it even a screw?  An allen key doesn't fit.  Tiny torx maybe?

(https://i.imgur.com/4riZ9TS.jpg)

(https://i.imgur.com/k5UVRzp.jpg?1)
Title: Re: Aerco MP-2 preamp - Part 2
Post by: goodcooker on November 17, 2017, 07:22:06 PM
Mine fell off the second time I used it. Thought I had it tightened back down with a very small flathead screwdriver that seemed to fit then it fell off again and now I can't even find it,

Good thing I run it on +20dB all the time anyway  :-X
Title: Re: Aerco MP-2 preamp - Part 2
Post by: yug du nord on November 17, 2017, 07:44:55 PM
With my old Aerco, a knob would come loose.  I could tighten it with a small/tiny flat-head screw driver that was on my Leatherman multi-tool. 
It would eventually come loose again.. and I'd tighten it again.
Loved that box!!
Title: Re: Aerco MP-2 preamp - Part 2
Post by: audBall on November 17, 2017, 09:45:22 PM
One of the knobs on my MP-2 fell off.  Has this happened to anyone before?  Do I just need to find the right screwdriver to tighten the little screws on the knob?  Is it even a screw?  An allen key doesn't fit.  Tiny torx maybe?

A torx is essentially a notched allen. If the one you have doesn't fit, either the set screw is worn or you need metric vs standard, or otherwise.
Title: Re: Aerco MP-2 preamp - Part 2
Post by: goodcooker on February 17, 2018, 01:43:16 PM
My MP2 has been doing some squirelly stuff. Last night the recording was really hissy and had a couple of big distorted jumps. Opened it up today to see if I could see any loose wires or anything obvious and the batteries are starting to swell up- one of them looks ready to pop. Has anyone found a source of replacement batteries? Might just send it back to Jerry for a checkup anyway.

Edit - The local batteries plus store said they could put something together then they said they couldn't. They found some 7.4V LiPo packs just like the one's that Jerry used but one 7.4V pack instead of two 3.7V packs. I ordered a couple to see if they work.


Also thinking using an external will solve some problems - never have used the DC input. I have a ton of 5V batteries and don't want to buy any other voltage just to run the MP2 - anyone ever use a voltage up converter - you can get cheap ones to convert 5V to 9 or 12 V.
Title: Re: Aerco MP-2 preamp - Part 2
Post by: Hypnocracy on March 04, 2018, 10:17:43 AM
Sorry to hear that the internal Lipo has swelled up. It’s nice not to drag along external batteries. The only issue I had running external was with a voltage ranging Tekkeon that refused to send 9-12v to the MP2 and I got a brick walled signal on the DR2d...ran great on my other Tekkeons that set voltage with dip switch’s.
Title: Re: Aerco MP-2 preamp - Part 2
Post by: goodcooker on March 26, 2018, 12:18:00 PM


So I talked via email with Jerry about my MP2. He said that a 1/16ths allen wrench is what's needed to tighten the screws on the knobs that came loose.

About the batteries - he said he doesn't have any on hand and that trial and error with buying some and seeing if they will fit is the way to go - he would have to do the same thing as me so it would be cheaper and easier to do it myself.

I already bought some that don't fit the case. It's a really tight fit and has to accommodate the little breakout board that the batteries attach to. I haven't been able to find an exact replacement for the batteries that were in it to begin with.

Title: Re: Aerco MP-2 preamp - Part 2
Post by: goodcooker on April 08, 2018, 02:16:05 PM

Update for anyone who might be taking their MP2 off the shelf soon and the internal batteries are a little long in the tooth.

Found some suitable replacements for pretty cheap at ThinkRC.com. - http://www.thinkrc.com/product_reviews_write.php?products_id=2810 (http://www.thinkrc.com/product_reviews_write.php?products_id=2810) - lower capacity but they fit in the case which was the biggest challenge.

The weird news is that even though the batteries charged right up after installing them I couldn't get the pre to function. A few emails back and forth with Jerry and he recommended that I put power to the DC input jack since it is wired outside of the on/off switch circuit. Sure enough it works that way so that means the switch has failed. I'm fairly handy but I'm not sure if I'm up to the task of installing a new switch - it's right next to a double stack circuit card and everything is glued in.

Want to get this up and running again to use with the MBHO subcards. I think it will be a perfect match.

I'll give a further update on the replacement battery performance once I get a chance to get the switch fixed. Maybe I'll start by shooting some contact cleaner in there a couple times and working the switch back and forth to see if it's just really dirty....
Title: Re: Aerco MP-2 preamp - Part 2
Post by: dactylus on April 08, 2018, 02:19:34 PM
^Thanks for the update!
Title: Re: Aerco MP-2 preamp - Part 2
Post by: spyder9 on May 14, 2018, 12:15:47 PM
I just ran mine over the weekend for the first time in a long while.  Still in luv.....   :cheers:
Title: Re: Aerco MP-2 preamp - Part 2
Post by: jbosco on May 16, 2018, 08:30:13 AM
Damn I miss my Aerco, wish I never loaned it out  :banging head:
Title: Re: Aerco MP-2 preamp - Part 2
Post by: goodcooker on May 16, 2018, 09:19:16 AM

Still having some problems with my Aerco so it's going back to Jerry. Long story short - the internal batteries died a sudden death - one day it worked fine the next day weirdness - so I replaced them. Unit wouldn't power on so Jerry suggested that the switch had failed and told me the external power jack is not wired through the switch. Built a cable for a DVD battery and it powered right up and seemed fine in a home test. Took it out for a show last week and every kick drum hit was horribly distorted. It's going back for a once over and any necessary repairs.

Anyone else have any problems running the Aerco from a 9V wally battery through the external DC input?
Title: Re: Aerco MP-2 preamp - Part 2
Post by: yug du nord on May 16, 2018, 10:20:59 AM
Anyone else have any problems running the Aerco from a 9V wally battery through the external DC input?

This is how I ran my old Aerco for a few years...  zero problems.
I used a Radio Shack Adapta-Plug to connect it to a 9v DVD battery.

Personally, I would run an external battery all the time.  Relying on internal rechargeable batteries would stress me out.

And man, I also miss my Aerco.....
Title: Re: Aerco MP-2 preamp - Part 2
Post by: jbell on May 16, 2018, 10:25:09 AM
I'd scrap the internal rechargeable and go with 9v's!!  I always ran mine with an external as well it worked great.
Title: Re: Aerco MP-2 preamp - Part 2
Post by: spyder9 on May 16, 2018, 11:00:24 AM
The internal bat mod has been a blessing for me.  It made my rig smaller, bag much lighter, with no issues whatsoever.  I get the usual 9-10 hours, just like I did with alkalines.  :coolguy:
Title: Re: Aerco MP-2 preamp - Part 2
Post by: darby on May 16, 2018, 11:05:05 AM
Anyone else have any problems running the Aerco from a 9V wally battery through the external DC input?

I ran my first AERCO that way all the time
the second one I sent back a second time to Jerry to refit in a new box with internal rechargeables
after sending it in once to fix the circuit board... it took him 9 MONTHS!
by the time I got it back I was ready to sell it and move on to other boxes

good luck with this Roger

Title: Re: Aerco MP-2 preamp - Part 2
Post by: goodcooker on May 16, 2018, 12:08:30 PM
One of the selling points for me is the internal rechargeable batteries. Less stuff to carry and one less cable to route. The actual replacement of the internals was really simple - the hard part was finding batteries that fit.

Since the DC input isn't wired into the on/off switch when it's plugged in it's "always on". I left it plugged in after my last test and the next afternoon the old ass DVD battery still had 1 out of 3 lights - that's around 30 hours later on a 6000mAh DVD battery that's probably 10 years old by now. :o

I sure hope it doesn't take months to give it a checkup and any needed repairs...
Title: Re: Aerco MP-2 preamp - Part 2
Post by: spyder9 on August 09, 2018, 09:52:29 AM
Well, my LIPO's finally gave out when I was in Colorado last month.  95 degree heat will kill lithiums every time.  My bats lasted 6 years.

Any hoot, Jerry installed the following during the original mod:  Max Force 7.4V 900mah 25C 2S1P  Sadly, they're not made anymore.

Below is what I found on the 'net.  GoolRC 7.4V 900mah 25C 2S   They go for about $10/piece and are the exact same size as the Max Force.  They arrived yesterday and charged up fine during the overnight.  Maiden voyage is tonight. 
Title: Re: Aerco MP-2 preamp - Part 2
Post by: dactylus on August 09, 2018, 10:37:55 AM
^ Good luck on the maiden voyage!
Title: Re: Aerco MP-2 preamp - Part 2
Post by: goodcooker on August 09, 2018, 12:22:15 PM

I accidentally pulled out the wires from the PCB when I was replacing my LiPo batteries. I sent it back to Jerry and he compared fixing it to brain surgery. I may have been careless but be extra careful not to put any stress on the wires that go to the PCB when you are replacing the batteries. I think I messed mine up when I was trying to get some batteries that were just a millimeter or two too large to fit in the little space in the case.