Hi again guys,
I have an Aphex 107 'Tubessence' pre amp that is giving my friend problems.
The gain pots on both channels are very scratchy, and the 'scratchiness' increases for a period of time when phantom power is applied.
I measure .59VDC from ground to any leg of the gain pots. When phantom is applied this spikes to around 1VDC, before ramping dwn to .59v again. I am under the impression that no DC should be present on a pot.
When measuring pin 2 of the mic input with phantom power engaged, I get 44.3VDC.
Does anyone have a schematic I could use to troubleshoot? I guess I am looking for a leaky capacitor somewhere close to the potentiometer.
Advice is appreciated.