M-Audio Firewire 410 doesn't like China mics?

[bensommerfeld]

Hi guys,

I have a little problem with the M-Audio FW 410. I have 3 mics here to test with this device: Studio Projects B1, MXL V6 and AKG C3000B. I run them through the onboard preamps of the FW410. So far, so good.

But: With the B1 and V6 I get a "whistle" in the recorded signal, as soon as the Phantom power is turned on. Here's an example:

http://gload.de/files/e39003533c76d249599850be1.mp3

With the C3000B - no whistling! I can push the gain of the preamps to the top, but there's no whistling with the C3000B.

Can anybody tell me why my china mics are "whistling" with the FW410? Is this a matter of "quality" cause the C3000B is built in Austria / has better electronic parts integrated? Maybe a problem with the preamp impendance of the FW410?

Regards, Ben


EDIT: I also have the following infos:

Studio Projects B1: Current consumption 3 mA
MXL V6: Current consumption: 2,5 mA
AKG C3000B: Current consumption < 2 mA

And another thing about the C3000B:

"Back-electret mics require very high-impedance electronics, and AKG have coated the entire preamp with a specially formulated insulating varnish, which should improve reliability in humid environments."


Maybe it has to do with the power consumption of the mics and that the bus-powered FW410 can't provide enough phantom power?
I could test to run the FW410 with the external power supply - until now I run the device bus powered through my onboard firewire port.

On the other hand on the M-Audio page they say: "If you are connecting your M-Audio FireWire device to a 6-pin connector on your computer, the unit will be powerered through the FireWire cable - do NOT use the provided power supply when using a 6-pin connection!"

So I shouldn't use the external power supply...........:(

[rolo95]

Originally Posted by bensommerfeld

Hi guys,

I
Studio Projects B1: Current consumption 3 mA
MXL V6: Current consumption: 2,5 mA
AKG C3000B: Current consumption < 2 mA

......:(

Ahaaaa
that must be the reason...
if you see....
the akg is the less power hungry of the bunch...

so i figure that the phantom power circuit of the MAUDIO interface...

cant suport the correct voltage value at that current consuption value...

if you can i will be interested if you can measure the voltage
on the phantom power with the 3 mics...

and see what you get...
the other solution its to use an external phantom power supply
and see if the whistle have gone ( i think yes... )

Greets
Rolo.

[rolo95]

bump

[username]

sounds like you have a racist pre amp

[bensommerfeld]

THanks for your answers, guys.

I talked to M-Audio support and they had no idea what the problem could be - in their tests the unit worked with several cheap condenser mics.

I returned the Firewire 410 and got a Focusrite Saffire - no whistling there

Regards, B.