Topic: M-Audio's response to 48v phantom power bug

[Jonny Durango]

Here's a copy of an email I sent to M-Audio. Please send email to sales@m-audio.com and/or info@m-audio.com if you are also concerned about this problem.

<<

A rep from your company recently addressed the list of bugs associated with the Microtrack 2496. Among them, was the underperforming phantom power supply. Here is a copy of the reply as posted to rec.audio.pro and rec.arts.movies.production.sound

"BUG:
- 30v max on Phantom on stead of advertised 48v

ANSWER:

I believe our marketing mentions "Phantom Power", but never states
48v.  We took a prototype down to an equipment rental store, and they
let us go through their mic closet.  The MicroTrack provided enough
power for everything we tried, from the U87 to Sennheiser shotgun mics
and some esoterics.   So, is this a complaint that a mic didn't work,
or is it a complaint that the Volt-Ohm meter needle didn't go where
they wanted?"



In fact, your marketting DOES specifically state 48v phantom power as is apparent from page 6 of your own 2005 Product Guide.

http://www.m-audio.com/images/global/media/M-Audio2005Catalog.pdf

Likewise, every retailer and M-Audio dealer's website had advertised 48v phantom power before the MT's release (while they were still taking pre-orders) and most still advertise it even though it has been found that the unit may only deliver 30v of phantom power (according to Len Moskowitz of core-sound.com and others, see taperssection.com archives).

http://www.bhphotovideo.com/bnh/controller/home?O=NavBar&A=getItemDetail&Q=&sku=389807&is=REG&si=feat#goto_itemInfo
http://66.102.7.104/search?q=cache:aKjfIljToEUJ:www.audiomidi.com/Micro-Track-24-96-P6906.aspx+microtrack+48v&hl=en
http://66.102.7.104/search?q=cache:YUjbMmFMSFgJ:www.sweetwater.com/store/detail/MicroTrack/+microtrack+48v&hl=en
http://66.102.7.104/search?q=cache:EbZh4NftKBYJ:www.minidisco.com/microtrack.html+microtrack+48v&hl=en
http://72.14.207.104/search?q=cache:gqAJ7pUb-X4J:www.bananas.com/productdetail.asp/PID_8927+m-audio+microtrack+2496+48v&hl=en
http://72.14.207.104/search?q=cache:4SWOO0xgbGgJ:www.torcomp.com/products/product_detail.cfm%3Fproductid%3D48251%26ProductPriceID%3D208734+m-audio+microtrack+2496+48v&hl=en

Even such major retailers as Sweetwater, BH Photo Video and AudioMidi.com are advertising 48v Phantom Power.

As such, I believe this is a product defect that should be fixed and addressed in later revisions. Despite what your own testing indicates, it is true that many mics will not function properly with highly underrated phantom power supplies. Schoeps has confirmed that it's 12-48v phantom mics will only operate properly when powered by 12v OR 48v, not 12 TO 48v..

I'd like to thank you for making such a great product. I'm sure if you can work out most of the firmware bugs, and bring the phantom power supply up to it's rated voltage, it will be a VERY succesful machine. Please let me know how, or if you plan to address this issue. Thankyou!

--

Jonny Durango

www.jdurango.com

"If the key of C is the people's key, what is the key of the bourgeoisie?"

>>

Will post more when/if I get a response.

Jonny Durango

[it-goes-to-eleven]

Well done!

[Brian Skalinder]

Nicely written, Johnny, good stuff.

[pfife]

I'd love to see someone with some influence at M-Audio join this board.   I have a feeling he/she would get completely swamped though!

Good letter man.

[blackmikito]

"We took a prototype down to an equipment rental store, and they
let us go through their mic closet.  The MicroTrack provided enough
power for everything we tried, from the U87 to Sennheiser shotgun mics
and some esoterics."

You would think that a company dedicated to manufacturing audio recording equipment would have their own set of microphones to test with...

[pfife]

And would know that the amount of power probably affects the performance of the mics.

[musicsherlock]

"Works great with these mics! Let's release it!"

[blackmikito]

I can just see the next response....

"We're sorry, we couldn't update the firmware on our website because we can't get to a computer. The internet cafe down the street is closed on Thursdays."  

[BLOODYJACK]

This is a common problem on many budget sound boards and Especially on battery powered equipment, has anyone checked the other portable devices? eg R1 UA5 etc
http://www.rycote.com/products/pdf/The%20Feeble%20Phantom.pdf

[it-goes-to-eleven]

Excellent article, thanks!

[scb]

You would think that a company dedicated to manufacturing audio recording equipment would have their own set of microphones to test with...

what if this prototype fried every mic?  that would have sucked for them. 

i don't know how i'd feel as the rental place being the guinea pig for things like this

[wbrisette]

Here's a copy of an email I sent to M-Audio. Please send email to sales@m-audio.com and/or info@m-audio.com if you are also concerned about this problem.

<<

A rep from your company recently addressed the list of bugs associated with the Microtrack 2496. Among them, was the underperforming phantom power supply. Here is a copy of the reply as posted to rec.audio.pro and rec.arts.movies.production.sound

"BUG:
- 30v max on Phantom on stead of advertised 48v

ANSWER:

I believe our marketing mentions "Phantom Power", but never states
48v.  We took a prototype down to an equipment rental store, and they
let us go through their mic closet.  The MicroTrack provided enough
power for everything we tried, from the U87 to Sennheiser shotgun mics
and some esoterics.   So, is this a complaint that a mic didn't work,
or is it a complaint that the Volt-Ohm meter needle didn't go where
they wanted?"

As has been pointed out here already by way of that excellent article BloodyJack posted, there is a lot more to phantom power than 48v. OK, so they give me 30v, but what sort of current draw can I expect. I already ran into a problem with a piece of professional gear that couldn't give me the full 10mA that my Earthworks mic required. Is the MicroTrack going to give me 10mA at 30V? Anybody seen specs or tests on the current draw?

Wayne

[F.O.Bean]

great point wayne

[oleg]

Here's a copy of an email I sent to M-Audio. Please send email to sales@m-audio.com and/or info@m-audio.com if you are also concerned about this problem.

<<

A rep from your company recently addressed the list of bugs associated with the Microtrack 2496. Among them, was the underperforming phantom power supply. Here is a copy of the reply as posted to rec.audio.pro and rec.arts.movies.production.sound

"BUG:
- 30v max on Phantom on stead of advertised 48v

ANSWER:

I believe our marketing mentions "Phantom Power", but never states
48v.  We took a prototype down to an equipment rental store, and they
let us go through their mic closet.  The MicroTrack provided enough
power for everything we tried, from the U87 to Sennheiser shotgun mics
and some esoterics.   So, is this a complaint that a mic didn't work,
or is it a complaint that the Volt-Ohm meter needle didn't go where
they wanted?"

As has been pointed out here already by way of that excellent article BloodyJack posted, there is a lot more to phantom power than 48v. OK, so they give me 30v, but what sort of current draw can I expect. I already ran into a problem with a piece of professional gear that couldn't give me the full 10mA that my Earthworks mic required. Is the MicroTrack going to give me 10mA at 30V? Anybody seen specs or tests on the current draw?

Wayne

didnt you read , they did check some" esoterics"
might work , probably not :-)

[wbrisette]

didnt you read , they did check some" esoterics"
might work , probably not :-)

yeah. I'm holding my breath (right!) since my esoteric QTC1 and SR-77 mics aren't owned by a single person other than a handful of people in NH who make them and me. 

Actually if they would simply fix the digital input problem I would buy one simply so I could do a rough down and dirty two-track mix in the field from the Deva IV ... Of course this also assumes that it will handle a real AES signal.

Wayne

[nic]

didnt you read , they did check some" esoterics"
might work , probably not :-)

yeah. I'm holding my breath (right!) since my esoteric QTC1 and SR-77 mics aren't owned by a single person other than a handful of people in NH who make them and me. 

Actually if they would simply fix the digital input problem I would buy one simply so I could do a rough down and dirty two-track mix in the field from the Deva IV ... Of course this also assumes that it will handle a real AES signal.

Wayne

I think ToddR said he fed his Microtrack from the AES2(pro) line on his V3...

[oleg]

didnt you read , they did check some" esoterics"
might work , probably not :-)

Actually if they would simply fix the digital input problem I would buy one simply so I could do a rough down and dirty two-track mix in the field from the Deva IV ... Of course this also assumes that it will handle a real AES signal.

Wayne

it would make your deva, deva 5 :-)

[Jonny Durango]

Here's another one fired off today:

-------

As posted to rec.audio.pro by David Satz

<<
Pawel, please do not try to use the Schoeps CMC 6-- amplifier (whether
it is the xt version or not) with a power supply that offers neither
standard 12 Volt phantom powering nor standard 48 Volt phantom
powering. What will very likely occur with a 30-Volt supply is that the
voltage received by the microphone's circuitry will be in the 20s or
lower (because of the 6.8 kOhm supply resistors), and the microphone
will switch over to its 12 Volt mode.

In that mode, however, the microphone draws about 10 mA and that will
very likely bring down the power supply regulator in the recording
device, quite possibly causing damage to the MicroTrack if its circuit
is not protected. I have personally seen that occur with another
lightweight, portable preamp/ADC in which the "phantom power" supply
was not up to standard.

M Audio should certainly know about this issue; they experienced it in
the design of the DMP3 preamp, since its predecessor the DMP2 could not
properly power a pair of modern condenser microphones--not even
Neumanns at 2 - 3 mA apiece, let alone a Schoeps (4 - 4.5 mA) or any of
the types that require more current, such as the Shure KSM series (5 -
6 mA), the original AKG C 451 (6 mA), the CAD Equiteks (8 mA) or
Earthworks (10 mA). I had an email exchange with the designers, and the
eventual model DMP3 was a definite improvement (also in regard to its
input overload margins).

>>

Also posted to sci.electronics

<<

Actually a repair problem for a low noise microphone pre-amp but seems to be
a general design flaw.
Pre-amp uses a Burr Brown INA103 very low noise instrumentation op-amp.
In this M-Audio Omni i/o preamp and an outline design application in the
Burr Brown book show much the same circuitry.
The 48Volt phantom supply to the mike is protected by 6.8K limiter
resistors.
But to block the 48V DC to the op-amp there is a 10uF/100V electrolytic in
each line directly to the inv & non-inv i/p of the op-amp .

If , as seems in this case, a balanced line microphone with a short to
ground is connected to such a system
then the +48V / 0V across the elecrolytic will instantneously go to 0V
/ -48V with -48V
directly connected to the op-amp i/p powered from +-15V rails and according
to the databook
can be taken to only +-12V.

Blown input to this op-amp due to just the owner connecting a microphone.
Anyone familiar with this, adding limiting diode pair at each input ?
I see no point in replacing this 15 GBP/ 25 USD IC until this design flaw
is attended to or it will happen again should a fault to ground develop in a
mike or lead while the 48V power is on.

>>


I hope this is helpful in troubleshooting this problem. Please let me know when/if you plan to address this issue in a later revision of the Microtrack. Thanks!

--

Jonny Durango

www.jdurango.com

"If the key of C is the people's key, what is the key of the bourgeoisie?"

[oleg]

http://www.m-audio.com/index.php?do=products.list&ID=microphones
check the power requirement for m-audio mikes , isn't it strange :-)

[F.O.Bean]

this problem is minimal in my uses w/ it anyway

whats up w/ the damn auto-split

[rdvdijk]

whats up w/ the damn auto-split

M-Audio said they would look at it, but they have other bugs to fix / requests to grant which have a higher priority (for them). Let's wait and see how first firmware turns out..

Roel

[Jonny Durango]

Here's one of the initially released pics of the MT. Anybody notice anything strange?



Thanks cmoorevt!

Jonny Durango

[John R]

based on the photos and lit presented by m-audio, this could possibly become a very expensive glitch for them.  there are a lot more people out there receiving this thing than frequent this or any geek board.  what's going to happen when joe newsroom of bill homerecorder plugs his 48v mics into it and things need ot be replaced/repaired?

jr

[Colin Liston]

So if I plugged in my DPA 4023's did I screw them up?   

[it-goes-to-eleven]

You might want to contact DPA and ask them about powering at 30v.

[keepongoin]

i don't think you are going to fuck up your mics with less than 48 v.  some mics won't work.  others won't put out levels like they would normally.  that is what jon (jklabs) told a year ago after i plugged in my battery to my ps-2 with the polarity reversed and it would only put out 36 v.

[eric.B]

as long as this thing will sucessfully record bit perfect 16 44,48 and 24 44,48,96(when the firmware is updated) over spidiff..  this box is a winner..  I dont much care if this thing even takes a line in/mic in signal or has phantom power.. 

[Ed.]

as long as this thing will sucessfully record bit perfect 16 44,48 and 24 44,48,96(when the firmware is updated) over spidiff..  this box is a winner..  I dont much care if this thing even takes a line in/mic in signal or has phantom power.. 

i'm with ya on that one.

[BayTaynt3d]

I just got a B&H Pro Audio catalog in the mail last night. It had the MT in it, and right there in your face was "48v Phantom" listed as a feature...

[wbrisette]

you know just because they removed 48V from their claim of Phantom Power, that doesn't mean they are off the hook. If they followed the spec, then they are either at 12V, 24V, or 48V @ 10mA. They aren't going to be able to provide that amount of current at 30v, so they really are still in trouble.

Wayne

[cmoorevt]

Hopefully some of the larger customers (BH, Sweetwater and Guitar Center) can help get this straightened out, although I can't see how it could be fixed without the creation of a second version of the device or a major recall.

Also, apparently if you order this from M-Audio France or the M-Audio Spanish site, 48v is still an option.  No need for a translation on this:

"double préampli micro avec alimentation fantôme 48 V pour les micros de studio"
http://www.m-audio.com/products/fr_fr/MicroTrack2496-focus.html

-and-

"previos de micro duales con alimentación phantom de 48V para micrófonos de estudio "
http://www.m-audio.com/index.php?do=products.focus&ID=e592504d50209547321a128eec573913&FORCESTATICPAGE=1&setlocale=es_la

-and-

M-Audio Germany still has the photo showing the 48v button.  http://www.m-audio.de/us/MicroTrack-side-L.jpg

[BLOODYJACK]

I guess There will not be a recall Creative Nomad was on revision 3 before it became usefull to tapers

[F.O.Bean]

Hopefully some of the larger customers (BH, Sweetwater and Guitar Center) can help get this straightened out, although I can't see how it could be fixed without the creation of a second version of the device or a major recall.

Also, apparently if you order this from M-Audio France or the M-Audio Spanish site, 48v is still an option.  No need for a translation on this:

"double préampli micro avec alimentation fantôme 48 V pour les micros de studio"
http://www.m-audio.com/products/fr_fr/MicroTrack2496-focus.html

-and-

"previos de micro duales con alimentación phantom de 48V para micrófonos de estudio "
http://www.m-audio.com/index.php?do=products.focus&ID=e592504d50209547321a128eec573913&FORCESTATICPAGE=1&setlocale=es_la

-and-

M-Audio Germany still has the photo showing the 48v button.  http://www.m-audio.de/us/MicroTrack-side-L.jpg

i would email that directly to m-audio

[oleg]

http://www.neumann.com/forums/view.php?bn=neumann_mictec&key=1128358820&v=f
for 100+xx tappers

[bdasilva]

Most phantom powering units regulate the voltage that goes to the capsule to around 10 v...    The whole 48v is a starting point. My Oktavas  and my TLs both run fine with this unit... This 30v thing is no dealbreaker.

[Brian Skalinder]

This 30v thing is no dealbreaker.

For some mics, perhaps not others.  But as others have mentioned, we don't yet know how much current the MT is able to provide to the mics.  That could prove the deal breaker for certain power-hungry mics.

Me, I don't care - bit-transparent 24/48 S/PDIF input and I'm thrilled!

[it-goes-to-eleven]

Most phantom powering units regulate the voltage that goes to the capsule to around 10 v...    The whole 48v is a starting point. My Oktavas  and my TLs both run fine with this unit... This 30v thing is no dealbreaker.

48v isn't a starting point, it is an international spec.  Have you done any frequency response tests at 30v?

I believe the Schoeps capsules see 60 volts.

[Colin Liston]

I tried my 4023's.  I couldn't get a decent level. 

[mmedley.]

...as far as 48V being an "international spec" that is almost laughable...."phantom power" has always been ambiguous.....

While I agree it is certainly ambiguous and left wide open to interpretation...it is definitely a "standard."

IEC 268-15/DIN45596

[eric.B]

This 30v thing is no dealbreaker.

For some mics, perhaps not others.  But as others have mentioned, we don't yet know how much current the MT is able to provide to the mics.  That could prove the deal breaker for certain power-hungry mics.

Me, I don't care - bit-transparent 24/48 S/PDIF input and I'm thrilled!

yup   

[mmedley.]

This 30v thing is no dealbreaker.

For some mics, perhaps not others.  But as others have mentioned, we don't yet know how much current the MT is able to provide to the mics.  That could prove the deal breaker for certain power-hungry mics.

Me, I don't care - bit-transparent 24/48 S/PDIF input and I'm thrilled!

yup   

Yep, except 24/96.   I never plan to use phantom on this thing so I could really care less. I don't even have my MT yet. I had one on pre-order, but had to cancel due to some family circumstances. I should be picking one up in the next week though. Come on new firmware!

[anhisr]

my new note from Neumann
Dear Mr. Meyer,

thanks for the information. I'll put the M-Audio Microtrack 24/96 on my "problem list".
It is amazing how many manufacturers think they can save money, and design effort, by economizing in the wrong places. It's just like they would expect their TV to work perfectly with only 70 V, instead of 110V or 230 V.
And, the phantom power standard specifying 12V, 24V or 48V has been around since the 1960s....., so it's not that new.

Best regards,
Martin Schneider
Neumann Mic Development 

[John R]

my new note from Neumann
Dear Mr. Meyer,

thanks for the information. I'll put the M-Audio Microtrack 24/96 on my "problem list".
It is amazing how many manufacturers think they can save money, and design effort, by economizing in the wrong places. It's just like they would expect their TV to work perfectly with only 70 V, instead of 110V or 230 V.
And, the phantom power standard specifying 12V, 24V or 48V has been around since the 1960s....., so it's not that new.

Best regards,
Martin Schneider
Neumann Mic Development 

love that dry, German humor

[pietje]

In essence, it is a bit difficult to predict what happens with powering systems that simply do not follow the international standards.
...
It's just like they would expect their TV to work perfectly with only 70 V, instead of 110V or 230 V.
Best regards,
Martin Schneider
Neumann Mic Development 

love that dry, German humor

Funny, but exactly zero information. With a circuit diagram, that Neumann does not supply, it is not to difficult to predict what the effect is.  The effect can range from working propperly to not working at all. The customer who bought this expensive Neumann microphone asked for this specific information and got nothing. Electronics do not depend on international standards but on laws of physic.

[anhisr]

This was the first note he sent. 
Dear Mr. Meyer,

I'm afraid there is no defined behaviour for the KM140s with only 30 V. And for testing, one would have to simulate the complete setup: not only the voltage, but also the current resources etc etc. In essence, it is a bit difficult to predict what happens with powering systems that simply do not follow the international standards.

The KM140s might work fine; the maximum level they can handle before distorting could be relevantly lower; the internal circuit might make strange noises when it doesn't get enough current; in the worst case a minimal mains power voltage change might happen during recording, causing the microphone to stop working...

Out of curiosity, and for my files: which preamp or console are you using, that provides only 30 V.

Best regards,
Martin Schneider / Neumann Mic. Development 

[pietje]

This was the first note he sent

There was a simple question: I just wanted to know if I could damage the mics using only 30v phantom power.

This question was not answered, although the answer was funny.

[Colin Liston]

in the worst case a minimal mains power voltage change might happen during recording, causing the microphone to stop working...

Best regards,
Martin Schneider / Neumann Mic. Development 

Lovely.....

[nickgregory]

In essence, it is a bit difficult to predict what happens with powering systems that simply do not follow the international standards.
...
It's just like they would expect their TV to work perfectly with only 70 V, instead of 110V or 230 V.
Best regards,
Martin Schneider
Neumann Mic Development 

love that dry, German humor

Funny, but exactly zero information. With a circuit diagram, that Neumann does not supply, it is not to difficult to predict what the effect is.  The effect can range from working propperly to not working at all. The customer who bought this expensive Neumann microphone asked for this specific information and got nothing. Electronics do not depend on international standards but on laws of physic.

huh?  neumann sold their product to work with a standard.  they have no obligation to make it work with a non standard.  kind of like a tv manufacturer where their unit was manuf to be used wtih 110V AC, but you want to power it with DC...up to you to figure it out

[pietje]

huh?  neumann sold their product to work with a standard.  they have no obligation to make it work with a non standard.  kind of like a tv manufacturer where their unit was manuf to be used wtih 110V AC, but you want to power it with DC...up to you to figure it out

That is a good example. The question was: I just wanted to know if I could damage the mics using only 30v phantom power.
If the TV starts with a mains transformer the answer is: "Yes, you will see smoke coming from your TV"

For this microphone it is hard for the owner to figure out what happens, as there is no cirquit diagram available, For Neumann, with the cirquit diagram at hand it would be not to difficult to say something like: "The KM140 can be used on lower phantom voltages then 48 volts but the specs are then no longer guaranteed." Then the owner can start figuring out.

You are right, there is no obligation to answer, but I prefer vendors that do answer customers.

[F.O.Bean]

well, yinz are looking too depply into this IMO, if ya need phantom that freakin bad, buy a fuckin phantom power box, done deal

m-audio screwed up bigtime on this, the pics we saw said 48v and they didnt deliver, if neumann says the mics may be damaged, i'd start to figure out a way to pwer them the right way, like w/ phantom power boxes neumann and akg make nic phantom units and cheaper ones can also be found

ya'll cant expect this to change, just figure out a way around it

[it-goes-to-eleven]

You are right, there is no obligation to answer, but I prefer vendors that do answer customers.

in the worst case a minimal mains power voltage change might happen during recording, causing the microphone to stop working..

That seemed like an answer.  I assume that the 'stop working' bit would be only temporary and that he would be more specific if there was a chance of damaging the microphone.  But "stop working" can be interpreted in ways that would scare most mic owners..

[anhisr]

Oh,
   I have a V3 to work around it.  I was just finding out what Neumann had to say about it.  Not just what people thought or what other companies said about thier mics. That way if in a pinch or if I ever decided to stealth, I would know if there is a chance it would blow my mics. Information is king

[eric.B]

well, yinz are looking too depply into this IMO, if ya need phantom that freakin bad, buy a fuckin phantom power box, done deal

m-audio screwed up bigtime on this, the pics we saw said 48v and they didnt deliver, if neumann says the mics may be damaged, i'd start to figure out a way to pwer them the right way, like w/ phantom power boxes neumann and akg make nic phantom units and cheaper ones can also be found

ya'll cant expect this to change, just figure out a way around it

I agree...

Q:  What is required to power the Neumann km140?
A:  48 V ± 4 V

Q:  What are the specs on the MT2496 in terms of phantom power?
A:  Well, It was stated in early specs that the MT2496 put out 48v phantom, but upon testing, it only puts out 30v.

48 V ± 4 V   does not equal     30 V

edit:  also.. I dont blame Neumann for not giving you a direct answer..   They list specific specs for their power needs.. 

[pfife]

well, yinz are looking too depply into this IMO, if ya need phantom that freakin bad, buy a fuckin phantom power box, done deal

m-audio screwed up bigtime on this, the pics we saw said 48v and they didnt deliver, if neumann says the mics may be damaged, i'd start to figure out a way to pwer them the right way, like w/ phantom power boxes neumann and akg make nic phantom units and cheaper ones can also be found

ya'll cant expect this to change, just figure out a way around it

This is the correct answer.  Not to mention, it'll probably be 3 days and everyone will want to run a pre in front of this thing anyways... I don't forsee everyone abandoning their +$1000 preamps for the preamps/A/D in a $400 consumer/prosumer product.  Not at all.

I'd also like to add that even if it were +48v phantom power, you'd then have even worse problems with the battery life.

I know it sucks, and seems like they are pulling a fast one w/ some false advertising and shit, but I don't see this being fixed...

[F.O.Bean]

well, yinz are looking too depply into this IMO, if ya need phantom that freakin bad, buy a fuckin phantom power box, done deal

m-audio screwed up bigtime on this, the pics we saw said 48v and they didnt deliver, if neumann says the mics may be damaged, i'd start to figure out a way to pwer them the right way, like w/ phantom power boxes neumann and akg make nic phantom units and cheaper ones can also be found

ya'll cant expect this to change, just figure out a way around it

This is the correct answer.  Not to mention, it'll probably be 3 days and everyone will want to run a pre in front of this thing anyways... I don't forsee everyone abandoning their +$1000 preamps for the preamps/A/D in a $400 consumer/prosumer product.  Not at all.

I'd also like to add that even if it were +48v phantom power, you'd then have even worse problems with the battery life.

I know it sucks, and seems like they are pulling a fast one w/ some false advertising and shit, but I don't see this being fixed...

GREAT point w/ the battery point

maybe they had a choice:
1. put the full 48v phantom in and have HORRIBLE battery life, or
2. just leave it at 30v, where most mics would work, and have a little better battery life?

as a company, i probably would have left it at 30v as well, i mean its not hard to come by true 48v phantom, granted it is another box or two, at least you know youre mics are not gonna get ruined

also, sucks for you stealthers, but most stealth mics are powered off of battery boxes anyway so.......

[F.O.Bean]

also, having 2 battery boxes>mt is still about the same size as prolly mp2>d7/8 or even mp2>sbm1>d7/8

[it-goes-to-eleven]

I'd also like to add that even if it were +48v phantom power, you'd then have even worse problems with the battery life.

I would expect that the mic will still require the same amount of power and the battery drain will be comparable. So if Schoeps require 4 mA at 48 volts, they'll want around 6.4 mA at 30v.  So I wouldn't expect savings there.  Some might even draw more because they're outside the design spec.

It is very possible that the 48v supply would be less efficient than a 30v circuit. I agree that there must have been a reason they couldn't do 48v

Regardless, I'd rather supply the MT with more juice via a USB power pack than put another device (which also requires power) in my audio signal chain.

[pfife]

I'd also like to add that even if it were +48v phantom power, you'd then have even worse problems with the battery life.

I would expect that the mic will still require the same amount of power and the battery drain will be comparable. So if Schoeps require 4 mA at 48 volts, they'll want around 6.4 mA at 30v.  So I wouldn't expect savings there.  Some might even draw more because they're outside the design spec.

It is very possible that the 48v supply would be less efficient than a 30v circuit. I agree that there must have been a reason they couldn't do 48v

I'll go with it bro!  You know way more about this stuff than I... It just seemed logical to me.

[Colin Liston]

I wrote DPA about the 48 volt issue, and got this repsonse:

Hi Colin,

You should have no problem.  The mics will reach full performance down
to 28 volts, and can not be damaged by low voltage.

Best Regards,
 

DPA Microphones, Inc.
691 Gray Mountain Drive
Lyons, CO  80540
303-823-5830 (fax)
www.dpamicrophones.com


Hell yeah bitches!

[nickgregory]

the response on the DPA 406x line?

[Simp-Dawg]

dpa has an office right nearby in lyons?  maybe i need to audition some mics

[Colin Liston]

the response on the DPA 406x line?

Sorry about that.  I asked about my 4023's, nothing else. 

[nickgregory]

the response on the DPA 406x line?

Sorry about that.  I asked about my 4023's, nothing else. 

cool, good to know as I have the 4022s

[pjdavep]

the response on the DPA 406x line?

Bruce from DPA sent me this info the other day -
"The typical range of voltage we recommend is between 4.5V and 9V with
the spec set at 6V. No caution needs to be taken at these levels.
No significant change in specs occurs when varying the voltage. Voltages
below 4.5V are insufficient to power the mic.

However:
It is more about amperage than voltage.
DPA minimic's are actually designed to handle a maximum current
of 7 mA. The incorporated 6.8 kOhm resistors on a standard
P48 V systems limits the current draw to exactly 7 mA.
When calculating the correct series resistor to be utilized with
a minimic, we always consider 1 mA as the normal current draw
in order to supply the mic. satisfactorily. You'll NOT gain any
better performance from the mic. by raising the current up to the
maximum of 7 mA."

Since the Microtrack puts out 4.5v (instead of the advertised 5v) on it's mic input, I'm a little worried that the voltage will dip below 4.5v after an hour or two of usage.  I'm talking about using something like the dongle that "Freelunch" made (see Rig Pictures section).  I need to run some tests to make sure it doesn't go below 4.5v at any point.

Later,
   pjdavep

[BayTaynt3d]

I wrote DPA about the 48 volt issue, and got this repsonse:

Hi Colin,

You should have no problem.  The mics will reach full performance down
to 28 volts, and can not be damaged by low voltage.

Best Regards,
 

DPA Microphones, Inc.
691 Gray Mountain Drive
Lyons, CO  80540
303-823-5830 (fax)
www.dpamicrophones.com


Hell yeah bitches!

On a mic-by-mic basis maybe...

[cmoorevt]

I heard back from M-Audio today about this issue. Here is the email:

I have forwarded your email to our developer, but at this point I cannot offer you a solution. We are working on a firmware upgrade, but are not made aware yet by the developer if the phantom power will be upped to 48 volts or not in a hardware upgrade. We apologize for the inconvenience, but we do ask that you try out your microphones and the supplied phantom power should provide enough power for them.

Please let us know if you need further assistance.

Not sure if anyone else has received similar responses but this is the first I have heard about a hardware upgrade.  Not to imply that one is imminent but at least they seem aware of the issue(and are not denying that 48v was part of the initial marketing), and seem to be making attempts to fix it.

[anhisr]

M-Audio called me today about an email I sent them.  I quoted the Neumann response to the 30V question.  They asked who I talked to and they are now going to call them and see if there will be a problem for Neumann mics.  Looks like they are at least trying to find out if it really is a problem for all or some.  I know they should take care of all but, that doesn't seem to be the road they are taking.

[Kevinlane]

I just bought some Studio Projects C4s,
Called them to ask what minmum voltage they'd operate at since it was not in the specs or on the site.
The tech (I forgot his name) told me that they would go down to 20v
Just tryin to save someone else the call

[Martinusb]

Dear MT-Friends,

there are 3 different types of phantom power:
48V (+-4V), using 6,8k feeding resistors
24V (+-4V), using 1,2k feeding resistors
12V (+-3V) using 680 Ohm feeding resistors.

The 30V are pretty close to the upper limit of the 24V type, 1.2k feeding resistors would be right.
Has anyone of you measured what feeding resistors the MT uses ?
I don´t have the device yet, so I can´t do the measurement at this time.
You cannot measure this in a direct way, but you have to draw a certain current and measure the voltage drop.

Many thanks for your help.

Best regards

Martinusb

[jpschust]

I just bought some Studio Projects C4s,
Called them to ask what minmum voltage they'd operate at since it was not in the specs or on the site.
The tech (I forgot his name) told me that they would go down to 20v
Just tryin to save someone else the call

you talked to alan im almost absolutely sure.

[jcme262]

waking this thread up again....

Anybody running AT853/933's  with Ph power? and if so what kinda batt life are you getting..

 I'm pretty much stealth and I'd like to terminate my mics over to mini xlr but if the battery life sucks I'll bag it cause I don't want pack around a charger as well..

Thanks

[Judderbar]

waking this thread up again....

Anybody running AT853/933's  with Ph power? and if so what kinda batt life are you getting..

 I'm pretty much stealth and I'd like to terminate my mics over to mini xlr but if the battery life sucks I'll bag it cause I don't want pack around a charger as well..

Thanks

Funny you should ask... the 4th time out with my MT and a gig over 2 hours, I remembered to leave it running afterwards as a proper recording time test:

AT853>Samson PM4>MT @ 24/48

File 1 (main set): 1:44:02
File 2: (Encores): 0:25:20
File 3: (Ambient noise after gig): 1:20:17

Total: 3:29:39

The max SPL capability seems unaffected by the lower phantom voltage too...


 
 

[jcme262]

The max SPL capability seems unaffected by the lower phantom voltage too...

Good news on the spl = bonus,  the other reason

Hey, funny I just located your post from a while back......I just pm'ed you
Seems like pretty good run times considering some of the thing's I've read, and although I've never lost power it seems like I'm getting about the same or not much more runtimes without Phantom.

 

thanks & +T

[Zaphod Beeblebrox]

I e-mailed Sennheiser regarding its compatability with my P48 416 shotgun microphone.  They told me that it should operate fine on 30 V.  I have not tested this since my first MT was dead out of the box.  I will probably never use the phantom power of the MT since I typically use a Sound Devices 442 as a front end and plan to use the MT as merely a backup in a worst case scenario backup situation.  It's good to know that I shouldn't try to use my Neumann Km-150 with the MT considering it costs 4 times as much as the MT.  I'm also hesitant to plug in my 416 since it also costs 3 times that of the MT.

-Zaphod

[branas]

quote from an email early in the thread:

"...since its predecessor the DMP2 could not properly power a pair of modern condenser microphones--not even Neumanns at 2 - 3 mA apiece, let alone a Schoeps (4 - 4.5 mA) or any of the types that require more current, such as the Shure KSM series (5 - 6 mA)"...

Just letting people know, I successfully ran (with phantom power from the MT) a KSM32 with zero problems for about 4 hours the other night (I had external power to the MT though).

[it-goes-to-eleven]

Here's a copy of an email I sent to M-Audio. Please send email to sales@m-audio.com and/or info@m-audio.com if you are also concerned about this problem.

<<

A rep from your company recently addressed the list of bugs associated with the Microtrack 2496. Among them, was the underperforming phantom power supply. Here is a copy of the reply as posted to rec.audio.pro and rec.arts.movies.production.sound

"BUG:
- 30v max on Phantom on stead of advertised 48v

ANSWER:

I believe our marketing mentions "Phantom Power", but never states
48v.  We took a prototype down to an equipment rental store, and they
let us go through their mic closet.  The MicroTrack provided enough
power for everything we tried, from the U87 to Sennheiser shotgun mics
and some esoterics.   So, is this a complaint that a mic didn't work,
or is it a complaint that the Volt-Ohm meter needle didn't go where
they wanted?"



In fact, your marketting DOES specifically state 48v phantom power as is apparent from page 6 of your own 2005 Product Guide.

http://www.m-audio.com/images/global/media/M-Audio2005Catalog.pdf

Likewise, every retailer and M-Audio dealer's website had advertised 48v phantom power before the MT's release (while they were still taking pre-orders) and most still advertise it even though it has been found that the unit may only deliver 30v of phantom power (according to Len Moskowitz of core-sound.com and others, see taperssection.com archives).

http://www.bhphotovideo.com/bnh/controller/home?O=NavBar&A=getItemDetail&Q=&sku=389807&is=REG&si=feat#goto_itemInfo
http://66.102.7.104/search?q=cache:aKjfIljToEUJ:www.audiomidi.com/Micro-Track-24-96-P6906.aspx+microtrack+48v&hl=en
http://66.102.7.104/search?q=cache:YUjbMmFMSFgJ:www.sweetwater.com/store/detail/MicroTrack/+microtrack+48v&hl=en
http://66.102.7.104/search?q=cache:EbZh4NftKBYJ:www.minidisco.com/microtrack.html+microtrack+48v&hl=en
http://72.14.207.104/search?q=cache:gqAJ7pUb-X4J:www.bananas.com/productdetail.asp/PID_8927+m-audio+microtrack+2496+48v&hl=en
http://72.14.207.104/search?q=cache:4SWOO0xgbGgJ:www.torcomp.com/products/product_detail.cfm%3Fproductid%3D48251%26ProductPriceID%3D208734+m-audio+microtrack+2496+48v&hl=en

Even such major retailers as Sweetwater, BH Photo Video and AudioMidi.com are advertising 48v Phantom Power.

As such, I believe this is a product defect that should be fixed and addressed in later revisions. Despite what your own testing indicates, it is true that many mics will not function properly with highly underrated phantom power supplies. Schoeps has confirmed that it's 12-48v phantom mics will only operate properly when powered by 12v OR 48v, not 12 TO 48v..

I'd like to thank you for making such a great product. I'm sure if you can work out most of the firmware bugs, and bring the phantom power supply up to it's rated voltage, it will be a VERY succesful machine. Please let me know how, or if you plan to address this issue. Thankyou!

--

Jonny Durango

www.jdurango.com

"If the key of C is the people's key, what is the key of the bourgeoisie?"

>>

Will post more when/if I get a response.

Jonny Durango

Suck it M-Audio!