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Behringer Xenyx 302 USB "fried" my AT2020? Mixers (Analog)
Old 15th July 2014
  #1
Here for the gear
 

Behringer Xenyx 302 USB "fried" my AT2020?

If this isn't the right place to post this thread, please excuse my ignorance. I'm as new as they come, so I looked around and this seemed like the best fit.

I'm trying to get a podcast started with a friend who lives 1k+ miles away. I bought (used) 2 AT2020's and a Xenyx 802 (non-USB) mixer, tested everything out in my home through a UCA-222/Audacity, and everything worked fine.

I shipped one mic and one XLR cable up to my friend in NY, who said "just get me what you have so we sound the same". To simplify things, I tell him to buy a 302USB and hook the mic and his computer up to that.

He bought the 302USB and we were able to record audio twice for over half an hour each time (if I recall correctly). He sounded fine both on Skype and in the mp3 he sent me. On the third try, his mic absolutely would not produce sound, though I could hear occasional clicking/static from him fiddling with every control on the 302 USB.

Today he took it to a Sam Ash and they said that the AT is "fried." Their explanation is that the 302 USB doesn't put out enough phantom voltage for the AT and that this condition ruined the mic.

Does that sound right? I know the 802 I'm using is a (slightly) more robust board, but this thing worked on both the 802 and the 302USB, albeit only twice in the latter case.
Old 15th July 2014
  #2
Gear Maniac
 

That sounds highly unlikely. Reports of dead AT2020 mics pop up on this forum from time to time, in my opinion it's more likely that if Sam Ash tested the mic and it didn't work then it has probably gone faulty for another reason.
Old 15th July 2014
  #3
Here for the gear
 

Thanks, Fardly. If you don't mind, could you explain why that's unlikely?
Old 16th July 2014
  #4
Gear Maniac
 

Low phantom voltage wouldn't fry anything, it would just cease to work. The fact that it worked fine for several hours means that the phantom power was ok - if there was an issue with insufficient power it would have never worked properly. This info from Rane corp explains a bit about it - Pro Audio Reference P
Old 16th July 2014
  #5
Quote:
Originally Posted by The Vix View Post
...Today he took it to a Sam Ash and they said that the AT is "fried." Their explanation is that the 302 USB doesn't put out enough phantom voltage for the AT and that this condition ruined the mic. ...
Using the term "fried" inplys that some components in the mic were burned out or otherwise damaged because the voltage may have been too low.

The IEC standard the specifies how phantom power circuits are wired provides for specific values of resistors for the (3) usual Phantom power specifications; P48 (by far the most common, P-24 rarely used, and P-12 sometimes used.

The Behringer 302 USB mixer does not meet the IEC phantom power standard, I recall they use a 15 volt system with non-standard series resistors. I haven't seen the Behringer schematic for a couple of years and don't have a copy handy, but I vaguely recall that the input may unbalanced (XLR pin3 is grounded?), and that they use an unbalanced PP system on pin-2 only. The AC powered Behringer uses a correct P48 system.

In a normal IEC standard PP system, having low phantom power voltage with the correct series current limiting resistors cannot result in any mic damage if the PP voltage is too low.

That is not the case with the weird and non-standard input of the 302USB.

It is a strange system and I would not be at all surprised if it could very well damage some mic circuits.
Old 17th July 2014
  #6
Gear Maniac
 

Thanks Lotus. I knew I shouldn't have assumed the mic input was in any way 'standard' - apologies to the OP for the misguided suggestions. It does make it more likely that the mixer could cause problems, but very hard to be sure without a post-mortem.
Old 17th July 2014
  #7
I wouldn't go beyond saying "I wouldn't be surprised" without examining the mic and the mixer. I remember being very surprised by the PP circuit. The only small mixer that I've seen that was even worse was a little Rolls which also had a non-standard set up and had a 3.5 mm jack for powering computer electret mics at 10 volts in connected in parallel with an unbalanced XLR through a dropping resistor.

In this case, the problem may very well be simply a bad AT2020, but there may also be a small possibility that the San Ash verdict is correct as bizarre as it sounds.

I don't recall the resistor values in the Behringer, but if they are low enough and allow too much current to flow, that could cause a possible component failure.

The strange part of all this is that the mic worked at all, since it is rated for operation at 48 volts only.

I also downloaded the 302 "Quick Start guide, and noted some changes since the last time i looked at one . I remember the old 302 Gude stated the 302 had switchible phantom power and could run at either +15 volts or at +48 volts. That was a clear error in the Guide, since there were (2) models of the Behringer 302. The plain "302" which has an external power supply, and in fact had +48 volt phantom power, and the 302 USB bus powered version that had +15 volts on the XLR input at all times There was no "switchable" version.

The current Guide makes no mention of the PP voltage at all and the mixer itself simply has "Phantom Power" printed on the front panel near the connector. I'm guessing that Behringer continues to produce the 15 volt version, USB bus powered version, but who knows since the don't specify anything related to PP on this unit anymore.
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