Pre amp fault

[Addolff]

Need some help here please.

I have a Krell KSP 7B pre / KSA100S power amp which has recently been giving me problems

When I turn the combo on, most times it is fine, everything quiet. After a while though a high pitched 'white noise' type sound is heard - even with the volume muted.

In addition, sometimes there is a hum, apparent on all sources, but worst with the phono stage. It will be virtually silent, then this too suffers with hum.

When I use another pre amp, no problem.

Any help would be really appreciated.

[analog_sa]

These symptoms are not sufficient to pin-point a simple cause. What level of experience/abilities in electronics do you have?

[AndrewT]

one channel or both?
does it change channels when you swap interconnects?

[Addolff]

Thanks for your reply.

Very little electronics knowledge - I can use a multi meter to test the simple stuff and can use a soldering iron.

I just wondered if the symptoms may have been a dead giveaway to an experienced hand for a particular fault - leaking capacitors or something.

The thing that is intriguing me the most is that the 'white noise' I described is apparent even with the volume muted.

[Jan Dupont]

What your reply to Andrews question ??
It could brings us closer to the problem.....

Your volume sits in the front end of the circuit, so no mystery there......

I would first suspect a bad soldering, and properly a soldering to ground since you sometimes get hum.........