I assume you've checked all input and output connections? Do you have another preamp you can substitute to verify?
AUDIO RESEARCH PH7 troubleshooting
Hello I've got a problem with my PH7, the right chanel becomes more and more noisy. Of course I changed all tubes, but the noise is still there. I ve heard about a probleme with some resistors on this preamp that became noisy , is there someone who has this problem and solves it ?Thanx