DMP3 hums.....and it's not because it doesn't know the words....

S

Simmons

New member
When I engaged the phantom power (and crank the gain at about halfway) on my DMP3 I can hear a low level (and low freq) hum. It's barely audible, but after stacking a few tracks, it becomes more obvious....especially in quieter acoustic passages. When I use it without phantom power it's completely quiet.

Has anyone else experienced this with the DMP3?

Thanks,
Simmons
 
Simmons said:
When I engaged the phantom power (and crank the gain at about halfway) on my DMP3 I can hear a low level (and low freq) hum. It's barely audible, but after stacking a few tracks, it becomes more obvious....especially in quieter acoustic passages. When I use it without phantom power it's completely quiet.

Has anyone else experienced this with the DMP3?

Thanks,
Simmons [/QUOTE




Either you have a bad mic cable (wire not fully soldered) or the balanced connection in your DMP3 has a bad connection. The Hum is DC voltage being amplified. This should normally be nulled if the circuit is properly working. Chech your cable first.
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I would also check the cables, mic to pre and pre to card.
What mic are you using? Might try another also.
I've noted with another pre (MQ3) with a tube mic that I also get a 60Hz hum if the phantom power is left on.
 
Thanks for the answer guys.

I think it know the what the problem is. I'm using a power transformer to "step down" the current from 220v to the DMP3s North American transformer. I've just ordered an EU verison of the transformer for 30 Euros. In theory though, the transformer SHOULD be regulating the current correctly....with no audible hum, I mean.

To answer you questions directly...I'm using two brand new Moster cables, an SP C1 and 2 Oktava MK-012. The hum happens in any setup with any mic and it DOESN'T happen on my other pre-amps.

Simmons
 
Is that power transformer anywhere near the preamp or cables? It could be injecting hum by induction into the system.
 
the power transformer's no where near and cables or the pre...

Stranger yet...it seems to get a little worse after the unit's phantom power has been engaged for a few minutes....as if it needs to warm up......to hum.

...so I can assume no one else has had this problem. I feel pretty certain it's the transformer. I'll know in a couple of days when I get the EU version of the power transformer.
 
Simmons said:
Has anyone else experienced this with the DMP3?
Click to expand...
Yes, I have experienced the same situation. As there were no problems with cables/connections and power supply lines, I'm left in the dark as to figure it out, and left with the solution of not employing the phantom power. Other than that, it's a great pre!
 
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