Topic: Cheap and compact... AT853 as your only mics....

[bdasilva]

For you tapers that have run these... Could a set of AT853s w/ phantom power and all the caps be good enough to be your only set of mics?

[The Kilted Taper]

I wouldn't see why not. You could do a lot worse.

[poorlyconditioned]

For you tapers that have run these... Could a set of AT853s w/ phantom power and all the caps be good enough to be your only set of mics?

I'm using my AT853's a lot, and my answer is yes.  You can either use phantom power, or "three wire" battery power.  (I use a home-made battery box for this.)  Standard two wire power (eg., Soundprofessionals) will distort.

But you should probably be a little more careful about placement.  I've gotten great results running up close, either stack tapes,
or wearing them close up in the crowd.  Sometimes these are the best places to be anyway, eg., when you've got a bad room.  If you're taping farther away, like from the section, they don't sound as good (IMO).  I don't know why.  Anyway, in this case I'd try to get a board feed to compensate.  Mixed together it will sound great though!

  Richard

[Sanjay]

For you tapers that have run these... Could a set of AT853s w/ phantom power and all the caps be good enough to be your only set of mics?

I'm using my AT853's a lot, and my answer is yes.  You can either use phantom power, or "three wire" battery power.  (I use a home-made battery box for this.)  Standard two wire power (eg., Soundprofessionals) will distort.

how would such three wire battery power be done?  Is there a diagram around for this?

[poorlyconditioned]

For you tapers that have run these... Could a set of AT853s w/ phantom power and all the caps be good enough to be your only set of mics?

I'm using my AT853's a lot, and my answer is yes.  You can either use phantom power, or "three wire" battery power.  (I use a home-made battery box for this.)  Standard two wire power (eg., Soundprofessionals) will distort.

how would such three wire battery power be done?  Is there a diagram around for this?

There is a thread about this:
 http://taperssection.com/index.php?topic=18846.0;all
but this is for connecting the Samson adapters.  But I don't really trust the Samson quality.  I would try to use AT adapters only.

My homemade box is as follows:

There are three wires on each mic: Red, Yellow and Shield.  (Well, red and yellow are really a twisted pair, both containing the
same signal.)

Connect Red on each mic to + on a 9V battery.  Shields to battery negative terminal.
Put a load resistor (say 22K or 27K) between yellow and shield for each mic (two resistors).
Put a capacitor (say 2.2uF metal film) from the yellow wire to audio output (two capacitors).
Take audio outputs from the film capacitor (side opposite yellow wire) and from ground.
That's it!

Note: I soldered everything to avoid connectors between the batt. box and the mics.  I glued all the parts on top of a battery holder.  I run a single 3.5mm stereo plug out to minidisc/dat/etc.

The battery holder is about $5 at Newark.com (P/N 92C3807).
 
To start the power, just insert 9V battery on sliding tray.  Remove after show.

I'll post pictures of this if I can.  Well, the problem is after glueing I wrapped everything in shrinkwrap so you can't see the wiring.

  Richard

[Sanjay]

sweet and a big +T 

I have done the mod with the samson adapters before, piece of cake, but I wanted to make a box without the samson adapters and still achieve the same sound result.

So basically with your battery box, your AT's sound like the phantom powered mics but they don't have to use phantom or the stupid adapters do they?

If so this is exactly what I need, and i may put in a stepped gain stage in my box too.  I'll be plugging the mini xlr's into it

thanks thanks thanks again.
-sanjay

[spyder9]

Get the AT853RX and fahgeddaboutdit!  Great for stealth and very good for open in the TS. Won't compete w/ the TS mics (AKGs, Schoeps, or Neumanns), but if you are the only taper, your recordings will be the schnizzle!   Guaranteed. 

[poorlyconditioned]

Get the AT853RX and fahgeddaboutdit!  Great for stealth and very good for open in the TS. Won't compete w/ the TS mics (AKGs, Schoeps, or Neumanns), but if you are the only taper, your recordings will be the schnizzle!   Guaranteed. 

I agree, AT853Rx are great.  For convenience, just plug into phantom power.

But if you want to do both stealth *and* open, having a small battery box and no phantom adapter and power module is even better.  It saves money too *if* you can bodies and capsules cheaper (eg., Ebay).  But you'll have to look pretty hard to beat the killer AT853Rx prices though ($145 each at alphasoundandlighting.com).

I've tried both configurations (proper 3-wire batt box vs. phantom) and don't notice any difference in sound quality.

  Richard

PS: If you've recording quiet stuff, like acoustic or unamplified music, you are going to notice a small amount of noise on the AT853's though.  Not terrible, but if that's your gig, you'll want something better.

  Richard

[jeromejello]

i'll fluff the at853's as well.  personally i think they are the best set of under 800/pair mics out there.

richard... you need to put up some pics of that 3 wire battery box. 

i would love to ditch both the ps-2 and the spsb-7 for a well crafted 3 wire battery box.  ideally in an otterbox (although i would consider something else smaller) with mini xlr inputs and stepped gain would be nice (say 10-15-20 db)

[Sanjay]

i'll fluff the at853's as well.  personally i think they are the best set of under 800/pair mics out there.

richard... you need to put up some pics of that 3 wire battery box. 

i would love to ditch both the ps-2 and the spsb-7 for a well crafted 3 wire battery box.  ideally in an otterbox (although i would consider something else smaller) with mini xlr inputs and stepped gain would be nice (say 10-15-20 db)

I've got a prototype built already, built one this afternoon, I had the gain stages built previously, and I was working on a 48v phantom circuit for the adapters to integrate into one box, but if there is no quality difference between 3 wire and phantom I will simply do a 3 wire part.  Right now I have it built into a metal box about the size of a pack of cigarettes.  However I plan to make it smaller.

[Chad817]

this is pretty interesting.  so if i'm hearing this right, one of these 3 wire batt box jobs could give the performance benefits of phantom power without modding the cables?  I have a pair of soundpro cmc-4's that I've been meaning to get phantom modded, but maybe this would be an easier solution to bump up their performance.

[poorlyconditioned]

this is pretty interesting.  so if i'm hearing this right, one of these 3 wire batt box jobs could give the performance benefits of phantom power without modding the cables?  I have a pair of soundpro cmc-4's that I've been meaning to get phantom modded, but maybe this would be an easier solution to bump up their performance.

Yeah, I would give it a try.  For new users, go ahead and score the cheap ($145) AT853rx.  But for those who already have the SP or other ones, go ahead and try a 3-wire box.

By the way, there is no gain here.  In fact, in 3-wire mode, the mics will output a little *less* than the standard (SP, etc) batt. box.
Maybe something like 3 or 6dB less.  Anyway, there is no gain (or attenuation) in my unit.  Just power.

Photos coming...

  Richard

[Ray76]

i'll fluff the at853's as well.  personally i think they are the best set of under 800/pair mics out there.

richard... you need to put up some pics of that 3 wire battery box. 

i would love to ditch both the ps-2 and the spsb-7 for a well crafted 3 wire battery box.  ideally in an otterbox (although i would consider something else smaller) with mini xlr inputs and stepped gain would be nice (say 10-15-20 db)

Dang , you Indian folks are smart!

I've got a prototype built already, built one this afternoon, I had the gain stages built previously, and I was working on a 48v phantom circuit for the adapters to integrate into one box, but if there is no quality difference between 3 wire and phantom I will simply do a 3 wire part.  Right now I have it built into a metal box about the size of a pack of cigarettes.  However I plan to make it smaller.

[poorlyconditioned]

i'll fluff the at853's as well.  personally i think they are the best set of under 800/pair mics out there.

richard... you need to put up some pics of that 3 wire battery box. 

i would love to ditch both the ps-2 and the spsb-7 for a well crafted 3 wire battery box.  ideally in an otterbox (although i would consider something else smaller) with mini xlr inputs and stepped gain would be nice (say 10-15-20 db)

I've got a prototype built already, built one this afternoon, I had the gain stages built previously, and I was working on a 48v phantom circuit for the adapters to integrate into one box, but if there is no quality difference between 3 wire and phantom I will simply do a 3 wire part.  Right now I have it built into a metal box about the size of a pack of cigarettes.  However I plan to make it smaller.

You're using an opamp for gain, right?  If so, what chip are you using?  I built a simple circuit using an OPA2134 chip.

OK, I just took some photos:


My full AT853 rig, including a headphone mount (bought from Soundprofessionals.com, modified by me to wear around neck), a home-made battery box (3-wire), a home-made preamp, a minidisc, and a set of Shure E3 in-ear monitors.


Battery box and preamp box.


Battery box circuit.  (Preamp not shown, but standard design.)


Wearing the mics.


Removed windscreens, elements are approx. 90deg apart.

   Richard

[Humbug]

+t, and again in 12.

Lots of effort there, particularly liked the "mad prof" style blackboard circuit diagram.

[setboy]

Sanjay, poorlyconditioned keep us updated on this. i was going to phantom mod mine but if this sounds just as good (or close) i may do this


Raphael

[Zaphod]

+t, and again in 12.

Lots of effort there, particularly liked the "mad prof" style blackboard circuit diagram.

Heh that's funny because he is a professor! +T Richard that looks like a solid stealth setup!

[mattb]

Yeah, very cool! +T

[thunderbroom]

Could you modify this to have a 9V for each mic? I  I've searched around the forum for this a while ago, but I remember reading that you couldn't/shouldn't run 18V to both mics through a mini.  I would think that if you had two mini XLRs it would increase performance.  If not, why?

[setboy]

Could you modify this to have a 9V for each mic? I  I've searched around the forum for this a while ago, but I remember reading that you couldn't/shouldn't run 18V to both mics through a mini.  I would think that if you had two mini XLRs it would increase performance.  If not, why?

i think if you run 18v into them you are going to kill them

you can only run so much into them


Raphael

[Sanjay]

You can only run up to 10v into these mics before they fry, i'm wiring it with 1 9v to send 9v to each mic.  There is no reason to have to 9v's when one will go for quite awhile.

[thunderbroom]

So a 9v battery will send 9v of power to each mic?  I was thinking that the voltage would split between the two.

[Brendan]

i'll fluff the at853's as well.  personally i think they are the best set of under 800/pair mics out there.

richard... you need to put up some pics of that 3 wire battery box. 

i would love to ditch both the ps-2 and the spsb-7 for a well crafted 3 wire battery box.  ideally in an otterbox (although i would consider something else smaller) with mini xlr inputs and stepped gain would be nice (say 10-15-20 db)

I've got a prototype built already, built one this afternoon, I had the gain stages built previously, and I was working on a 48v phantom circuit for the adapters to integrate into one box, but if there is no quality difference between 3 wire and phantom I will simply do a 3 wire part.  Right now I have it built into a metal box about the size of a pack of cigarettes.  However I plan to make it smaller.

You're using an opamp for gain, right?  If so, what chip are you using?  I built a simple circuit using an OPA2134 chip.

OK, I just took some photos:


My full AT853 rig, including a headphone mount (bought from Soundprofessionals.com, modified by me to wear around neck), a home-made battery box (3-wire), a home-made preamp, a minidisc, and a set of Shure E3 in-ear monitors.


Battery box and preamp box.


Battery box circuit.  (Preamp not shown, but standard design.)


Wearing the mics.


Removed windscreens, elements are approx. 90deg apart.

   Richard

hey i was wondering how you modded those headphones to place the mics how you did? Any details? thanks alot

[poorlyconditioned]

hey i was wondering how you modded those headphones to place the mics how you did? Any details? thanks alot

I did not do the original headphone mount.  They are from SoundProfesionals.com, something like shown here:
  http://www.soundprofessionals.com/cgi-bin/gold/item/ISI-HMAB-1
(Those have a battery box too, mine just had the AT853 mics.)  These are just Sony "MD-101" headphones ($10 retail) with the speakers removed, a hole cut in the side and the mics glued (hot melt glue) in the space the speakers would occupy.  The cushions act as windscreens and cover the mic.  The only trick is you have to let the mic protrude a bit so the "vents" on the capsule are outside the plastic ear cap.  (This also allows you to change capsules.)  A final note: inside were AT933 bodies + adapters, then AT853 caps.  I'm not sure if the 933 body + adapter is smaller than the 853 body.  I think they are both about the same size.

So, you're supposed to wear those over your ears, and the mics will point forward.  But that looks wacky.  So I took a heat gun and bent/molded the headband so the mics point forward when you put them around your neck.  This is much more natural looking (who listens headphones at a concert anyway?) and also allows more natural movement (you can move your head as long as you keep your body facing the stage).

A funny point to this story.  I originally bought the headphone mount because they were on clearance and much cheaper than a plain AT853 pair.  But once I started wearing them I was hooked.

  Richard

[pfife]

I loved the stealth-mics in headphones as well...

[poorlyconditioned]

I loved the stealth-mics in headphones as well...

OK by popular demand here is the schematic for my variable gain preamp.  It is a simple modification of the one at:
  http://www.geocities.com/ferocious_1999/md/micpreamp2.html

Schematic:


It is based on a single 8pin DIP chip, like NE5532, OPA2134, LM833N, etc.  The voltage gain is from 2..11.  That is 3 to 10.5dB voltage gain, or 6 to 21dB power gain.  You can easily add more gain, but I don't really need it with the AT853 mics (and recording from a PA).

I'm interested to hear what others have to say about this amp.  I haven't used it much.  I usually just run line in on my MD or mic in on a UA5 or Presonus Firepod (eight inputs!).  The circuit was just a hacking exercise.

  Richard


  Richard

[lordbelial]

Thanks dude! You rock.

[lordbelial]

I guess I'm goona go this way.

Since my mics (CMC-4) terminate in mini plug end, I'll need to wire the two outputs to a single mini plug female, am I right?

[lordbelial]

hi!

Just to say that I recorded three heavy metal bands yesterday with the CMC4 in Hat, placed in X-Y config and the recording came out really amazing!

I'll post photos of my hat and my rig later.

Thanks everybody for the effort.

[Sanjay]

The 3 wire version battery box based off of poorlyconditioned circuit diagram is complete.  It isn't too pretty on the inside but its nice on the outside.  Mics connect with minixlr's and have a 1/8" output. 

Pictures coming later tonight or tom.

Box #1 is going overseas to Humbug.
Box #2 stays with me.

I have materials to build a few more and I could be enticed to make some.

[setboy]

I have materials to build a few more and I could be enticed to make some.

i may want one PM sent

[poorlyconditioned]

The 3 wire version battery box based off of poorlyconditioned circuit diagram is complete.  It isn't too pretty on the inside but its nice on the outside.  Mics connect with minixlr's and have a 1/8" output. 

Pictures coming later tonight or tom.

Box #1 is going overseas to Humbug.
Box #2 stays with me.

I have materials to build a few more and I could be enticed to make some.

Dear Sanjay,

Please include pictures/details of your preamp as well.  I always like to see home made gear!

  Richard

[Sanjay]

The 3 wire version battery box based off of poorlyconditioned circuit diagram is complete.  It isn't too pretty on the inside but its nice on the outside.  Mics connect with minixlr's and have a 1/8" output. 

Pictures coming later tonight or tom.

Box #1 is going overseas to Humbug.
Box #2 stays with me.

I have materials to build a few more and I could be enticed to make some.

Dear Sanjay,

Please include pictures/details of your preamp as well.  I always like to see home made gear!

  Richard

Hey,

The preamp is not done yet, I can tell you its a variation of the two channel preamp found on the jenson transformers page. The difference between that and this is that with mine you variably trim the gain from 0-60 anywhere inbetween instead of stops.  In addition opamps I am experimenting with are: LM2904m, lm2902n, motorola mc33558pt.  Also I have several varieties of twin pot pentometers.

I can't spell for shit.

Its half done but now that the boxes are done im gonna wait a bit to continue, i've spent too mcuh time on the battery boxes alone.  Plus im curious as to how good the microtrack pre is, and if this will do anything better.

[lordbelial]

PM Sent on the boxes and the preamp! I'm dying in whishes to see your work!

[Sanjay]

Alrighty as promised pictures, This is of the battery box, preamp still under construction.  soldering those tiny things is a bitch, and my burnt hands can attest to it.  And secondly mini xlr shit is so expensive, its smaller than regulars why is it more!

ok here you all are.

[Sanjay]

in hindsight it looks so simple but man oh man it was hard to get right.

[lordbelial]

Alrighty as promised pictures, This is of the battery box, preamp still under construction.  soldering those tiny things is a bitch, and my burnt hands can attest to it.  And secondly mini xlr shit is so expensive, its smaller than regulars why is it more!

ok here you all are.

+T for the Battery Box.

I'm dying in wishes to see the Preamp!

[thunderbroom]

I'm going to try making this on the weekend.  Thanks for the information!

[Weazel]

let me know how it goes. im studying this schematic all evening. will this work on at-933s too?
i see the red wire  (+)  goes straight to the mic this won't fry it?
and is it possible to use female 3,5 socket?. if i count 1=ground to mic 2=+ to mic 3= yellow left mic 4= yellow right mic. and 3,5 socket only has 3 solder points. so i need xlr?

[thunderbroom]

Put a load resistor (say 22K or 27K) between yellow and shield for each mic (two resistors).

What will the difference be between the 22k and 27k resistor?  I can only find the 27k if I buy a 100 pack assortment of resistors.


That's the only thing I need to put this together.

Thanks for this great info!
Thanks!

[poorlyconditioned]

Put a load resistor (say 22K or 27K) between yellow and shield for each mic (two resistors).

What will the difference be between the 22k and 27k resistor?  I can only find the 27k if I buy a 100 pack assortment of resistors.


That's the only thing I need to put this together.

Thanks for this great info!
Thanks!

I think either 22K or 27K is fine.  I forget what I used in fact.  When you fire it up, measure the voltage across the 22/27K resistor.  It should be approx. 1/2 of the battery voltage.  But anything between 2 and 5 volts is probably OK.  You just need room for a large voltage swing, ie., no overloading.

Enjoy...

  Richard

[lordbelial]

Yesterday I built my first battery box. No roll off because I only had 2,2 uF capacitors at home, but they were electrolytic capacitors. Will they work?

I know tantalum capacitors works better with audio applications. Anyway I'm gonna buy some tantalum capacitors, desolder the electrolytic ones and solder the tantalum ones again.

I used 1% 10k resistors instead of 22k or 27k

[poorlyconditioned]

Yesterday I built my first battery box. No roll off because I only had 2,2 uF capacitors at home, but they were electrolytic capacitors. Will they work?

I know tantalum capacitors works better with audio applications. Anyway I'm gonna buy some tantalum capacitors, desolder the electrolytic ones and solder the tantalum ones again.

I used 1% 10k resistors instead of 22k or 27k

Did it work for you?  Note; do *not* use tantalum for audio.  Electrolytics are actually OK (watch the polarity), but you probably want polyester or metal film.  At least that is what the 'golden ear' people say

  Richard

[M]

What is the estimated battery life in one of these 3 wire batt boxes?

Thanks

[lordbelial]

Yesterday I built my first battery box. No roll off because I only had 2,2 uF capacitors at home, but they were electrolytic capacitors. Will they work?

I know tantalum capacitors works better with audio applications. Anyway I'm gonna buy some tantalum capacitors, desolder the electrolytic ones and solder the tantalum ones again.

I used 1% 10k resistors instead of 22k or 27k

Did it work for you?  Note; do *not* use tantalum for audio.  Electrolytics are actually OK (watch the polarity), but you probably want polyester or metal film.  At least that is what the 'golden ear' people say


  Richard

Well, I think it worked, but it was strange becasue between the resistor I measured different voltages. Aprox 2 V in one and 1,75 V in other. Both resistors are 10kohm 1%, so I don't know what can cause this difference between the two voltages.

At this point, I think i'm powering the channels different. I mean, I'm powering one channel with 2 volts (0.2 mA aprox) and the other one with 1,75 V (0.175 mA aprox).

[poorlyconditioned]

Yesterday I built my first battery box. No roll off because I only had 2,2 uF capacitors at home, but they were electrolytic capacitors. Will they work?

I know tantalum capacitors works better with audio applications. Anyway I'm gonna buy some tantalum capacitors, desolder the electrolytic ones and solder the tantalum ones again.

I used 1% 10k resistors instead of 22k or 27k

Did it work for you?  Note; do *not* use tantalum for audio.  Electrolytics are actually OK (watch the polarity), but you probably want polyester or metal film.  At least that is what the 'golden ear' people say


  Richard

Well, I think it worked, but it was strange becasue between the resistor I measured different voltages. Aprox 2 V in one and 1,75 V in other. Both resistors are 10kohm 1%, so I don't know what can cause this difference between the two voltages.

At this point, I think i'm powering the channels different. I mean, I'm powering one channel with 2 volts (0.2 mA aprox) and the other one with 1,75 V (0.175 mA aprox).

That is close enough, just make sure they sound OK.  Try them out at a loud concert.  The mics can have different current draws (different FETs in the mics).

  Richard

[lordbelial]

Yesterday I built my first battery box. No roll off because I only had 2,2 uF capacitors at home, but they were electrolytic capacitors. Will they work?

I know tantalum capacitors works better with audio applications. Anyway I'm gonna buy some tantalum capacitors, desolder the electrolytic ones and solder the tantalum ones again.

I used 1% 10k resistors instead of 22k or 27k

Did it work for you?  Note; do *not* use tantalum for audio.  Electrolytics are actually OK (watch the polarity), but you probably want polyester or metal film.  At least that is what the 'golden ear' people say


  Richard

Well, I think it worked, but it was strange becasue between the resistor I measured different voltages. Aprox 2 V in one and 1,75 V in other. Both resistors are 10kohm 1%, so I don't know what can cause this difference between the two voltages.

At this point, I think i'm powering the channels different. I mean, I'm powering one channel with 2 volts (0.2 mA aprox) and the other one with 1,75 V (0.175 mA aprox).

That is close enough, just make sure they sound OK.  Try them out at a loud concert.  The mics can have different current draws (different FETs in the mics).

  Richard

Well, anyway, today I'm gonna buy some metal film capacitors and some gold 1/8'' jack plugs (male and female) and some good cable. Quality does matter. I really don't want crappy noises from the Battery Box because of the cables or/and plugs.

I'll let you know as soon as I 've build the second battery box prototype.

Thanks for the info and the effort.

[lordbelial]

Here are the photos from my brand new homemade battery box customiced for MZ N707 Sony MD recorder















haven't tried it yet on live recording. I made it yesterday night.

[Weazel]

nice work lord

[lordbelial]

nice work lord

Thanks dude!

Now I'm working in a selectable bass roll-off and a PCB design for the battery box.

[Weazel]

did you seen mine, with no bass roll off
http://taperssection.com/index.php?topic=38094.0

[lordbelial]

did you seen mine, with no bass roll off
http://taperssection.com/index.php?topic=38094.0

Yes I saw the topic some days ago, but I did not remember that you were the builder 

Nice BB.

[MLKLuke]

hi guys,
I'm quite a newbie of the taping world but I would like to start to make my own recordings

I willprobably buy new/used AT853 or AT933/943 mics and run them with a JB3

the problem is the battery box. I've seen you're realizing 9v 3 wire battery boxes for your equipments...my question is: would one of them succesfully replace a Sound Pro SP-SPSB-6 box with bass rolloff option? if yes...is it possible that some of you can realize one for me? I know it can seem bad to ask other people to do a thing for you and you should think "hey guy...do it by yourself!"...but I'm not an expert of electronic parts at all  so...can someone give me precise infos of what I would precisely need to correctly supply mics and if I would still need a bass rolloff option with a 3 wire homemade batterybox? thanks in advance

[lordbelial]

hi guys,
I'm quite a newbie of the taping world but I would like to start to make my own recordings

I willprobably buy new/used AT853 or AT933/943 mics and run them with a JB3

the problem is the battery box. I've seen you're realizing 9v 3 wire battery boxes for your equipments...my question is: would one of them succesfully replace a Sound Pro SP-SPSB-6 box with bass rolloff option? if yes...is it possible that some of you can realize one for me? I know it can seem bad to ask other people to do a thing for you and you should think "hey guy...do it by yourself!"...but I'm not an expert of electronic parts at all  so...can someone give me precise infos of what I would precisely need to correctly supply mics and if I would still need a bass rolloff option with a 3 wire homemade batterybox? thanks in advance

Hi!

If you're gonna run AT853 or AT933/943 a battery box should be enough. No need to do a 3-wire battery box. That would make you cut down the wires of the mini plug termination of your mics, and, if you're not an electronics mid or advanced user... better don't do it!

I'm running AT853 with SP-SPSB-1 with selectable bass rolloff and I'm quite happy with my recordings. Those mics can handle the most louder shows. I build myself a battery box but haven't used it yet. guess I need to build a new one because the miniplug connector in the end of my battery box does not fit with the miniplug connector (female) on my minidisc (my belowed extra gear).

[thunderbroom]

I finally got around to making this.  It turned out well, but I was quite suprised about the volume drop.  I think that you said about a 6db decrease, but I think it is a little more with this box.

Thanks for the help on this one.  If I can put this one together, any of you can build it!

I'll be getting a digital camera soon, so I'll put up some pics soon.

[Weazel]

you mean a 3 wire box?

[thunderbroom]

Yes, the three wire box.

[Weazel]

will the dynamics increased with a 3 wire box?

[poorlyconditioned]

I finally got around to making this.  It turned out well, but I was quite suprised about the volume drop.  I think that you said about a 6db decrease, but I think it is a little more with this box.

Thanks for the help on this one.  If I can put this one together, any of you can build it!

I'll be getting a digital camera soon, so I'll put up some pics soon.

Yeah, I never thought too much about the volume drop.  This might be a problem for NJB3 or other users, who are trying to go line in.

If you've got a preamp though, this will sound great.  I'm using this wiring into an Edirol UA5 and a Sony HiMD (mic in, low sens).  Results are great.

Oh yeah, this is not recommended unless you're familiar with some basic electronics.  Not much, but some knowledge is needed.  Like making cables, it is simple, but it takes some practice to make nice connections, get the wiring right, etc.  It is rewarding though .  Some sense of satisfaction, and better than paying $50 or more...

  Richard

[cybermansrev]

I finally got around to making this.  It turned out well, but I was quite suprised about the volume drop.  I think that you said about a 6db decrease, but I think it is a little more with this box.

Yeah, I agree recorded my first gigs with the 12V 3 Wire Bat Box this weekend, I've found about a 12db decrease. Certainly surprised me quite what a decrease, however as I had significant tinnitus the following day despite wearing earplugs I'm sure the mics would have previously distorted significantly with the 2 wire box from SP.
I think my next step is too rethink my design and make it interchangeable 2 or 3 wire powering.

[thunderbroom]

I ran it last night on a couple of local bands.  It was far quieter than 12db.  I looked at it in Audition and it was -35db or so, and that is with the gain on the JB3 at +12db.  Looks like I'm going to have to figure out the preamp as well.

[cgresq192]

What mods would I need to make to allow this to work on a JB3?

Basically I would like to use this as my battery box/preamp solution

[poorlyconditioned]

I ran it last night on a couple of local bands.  It was far quieter than 12db.  I looked at it in Audition and it was -35db or so, and that is with the gain on the JB3 at +12db.  Looks like I'm going to have to figure out the preamp as well.

That sounds *way* too low.  Hmm.  Not sure if something wrong there.  (I'm the one who sold you the battery box, right???)

  Richard

[thunderbroom]

No, I didn't buy it from you.  I rewired the box using a mix of the two different 3wire BB diagrams that have been offered up and modded it into an AD-20 and everything is cool now.  I don't know what happened with the first one I made...

[poorlyconditioned]

No, I didn't buy it from you.  I rewired the box using a mix of the two different 3wire BB diagrams that have been offered up and modded it into an AD-20 and everything is cool now.  I don't know what happened with the first one I made...

OK, well take a look at the figures/schematics/files in:
  www.cs.uwaterloo.ca/~mannr/AT853

I'm pretty sure there is something wrong with your setup.  It might be a few (like 10 or max 20)dB down, but not that much...

  Richard

[Sanjay]

maybe bad solder joints, this has happened to me before

[Humbug]

This probably is a daft question, but if I was to record an unamplified classical show, could I run:

AT933 > 3wbb > SPSPSB1 > Nomad JB3

To try and get some gain on the recording?

Or would the Sound Pro Box do nothing to boost the gain?

[poorlyconditioned]

This probably is a daft question, but if I was to record an unamplified classical show, could I run:

AT933 > 3wbb > SPSPSB1 > Nomad JB3

To try and get some gain on the recording?

Or would the Sound Pro Box do nothing to boost the gain?

The battery box does *nothing* to boost the gain.  In fact, a 3-wire box will have a bit less level, maybe 6-10dB less, than the regular (2 wire) battery box.

There are a lot of issues with gain.  Can you put mics directly into *line* input?  If you have a loud show, maybe.
- if you have "hot" mics, ie., sensitive mics output larger voltage for same sound level
    (generally condensers are about 20dB "hotter" than dynamic mics, and probably +-10dB variation in
     various condensors.  AT853 are medium hot.  Sennheiser MKE2 are a bit better.  Panasonic WM61A are
     *very hot*.  Panasonic WM60 are about -10dB colder than WM61, about equal to MKE2.)
- if you have *gain* on the line input

NJB3 does not have real gain.  It just boosts the *digital* signal, same as you would do in post.  So, don't bother.

Some other line inputs, like minidisc, have line gain, and quite a lot at that.  My old Sony MZ-R37 seems to have oodles of gain, I don't even need the mic input.  I *believe* Iriver has real gain on the inputs.

So, remember, battery box does not add gain.  Try the line input on your recorder.  If you can to within -12dB or so, you're fine.  If you're below -20dB or so, time to add a preamp.

  Richard

[Humbug]

So, remember, battery box does not add gain.  Try the line input on your recorder.  If you can to within -12dB or so, you're fine.  If you're below -20dB or so, time to add a preamp.

  Richard

Thats an excellent answer, thank you. At least I now know that running the two battery boxes together wont achieve anything.

I'm finding the AT933 > 3wbb runs around 12-13dB below the CMC2>SPSPSB1 recordings I make, when I'm running two rigs together.

For example at The Black Crowes a couple of weeks ago, I had to boost the recordings 16-18dB to bring them up to 0dB. For small club shows this is more like 12-14dB. I guess thats the tradeoff for the small size of the 3-wire battery box, but there might be a market for a 3 wire battery box + preamp all in one package.

[poorlyconditioned]

So, remember, battery box does not add gain.  Try the line input on your recorder.  If you can to within -12dB or so, you're fine.  If you're below -20dB or so, time to add a preamp.

  Richard

Thats an excellent answer, thank you. At least I now know that running the two battery boxes together wont achieve anything.

I'm finding the AT933 > 3wbb runs around 12-13dB below the CMC2>SPSPSB1 recordings I make, when I'm running two rigs together.

For example at The Black Crowes a couple of weeks ago, I had to boost the recordings 16-18dB to bring them up to 0dB. For small club shows this is more like 12-14dB. I guess thats the tradeoff for the small size of the 3-wire battery box, but there might be a market for a 3 wire battery box + preamp all in one package.

About 10dB is due to the battery box.  The other 6-10dB is probably due to the fact that CMC2 (AT831 or SP clone of same) is a bit "hotter" than the AT853/AT933/AT943.

Personally, I would ditch the NJB3 and record MD line in with line-in gain.  Even running compressed (ATRAC), I find the sound is very clean, and there are no random hard drive access noises that (some) people are experiencing.  But that is my own preference.

  Richard