hum even after input to preamp is disconnected

[eagles33]

eagles33

It will be the power supply,I had the same problem,I opened up the preamp disconnected the mains transformer wired in a new power supply plug in wall type and no more buzz,if you cannot get into the preamp then bin it and buy a new one is only option.

After so many tests I am convinced that it is the preamp. I replace other sources to the input where the preamp was and all was well. I also connected the preamp where other sources were and the hum just followed. Any feed back on what i concluded?

 

[trev57]

No no feedback as we all concluded that it was the preamp