Re: MicroTrack again
- From: "David Satz" <DSatz@xxxxxxx>
- Date: 29 Sep 2005 08:33:29 -0700
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).
If you like the MicroTrack well enough in all other respects, my advice
would be to use an outboard phantom power supply with it, such as the
Denecke PS-1A or PS-2. That will also keep the phantom supply from
decreasing the battery life of your recorder. And if the MicroTrack has
coupling capacitors at its microphone inputs, as I suspect that it
must, you could bypass the output capacitors which the Denecke supplies
have; the way the circuit board is laid out makes that relatively easy.
--best regards
.
- References:
- MicroTrack again
- From: Pawel Kusmierek
- MicroTrack again
- Prev by Date: 9 volts is 12 volts is 8 volts etc.
- Next by Date: Re: Stereo Line to Mono line.
- Previous by thread: Re: MicroTrack again: what is the *right* way to get 48V?
- Next by thread: synth->amp & house mix feed
- Index(es):
Relevant Pages
|
Loading
