Audioprism Mantissa tube preamp buzz

Try playing around with the input selector knob...it may not be seated properly. Or, try another input?

My Mantissa will buzz if the selector does not seat...a wiggle of the knob and it's gone. (the Mantissa are getting old)

Other than that...

good luck,

Dave

Is there a buzz coming from the outboard power supply? Perhaps there's a grounding issue there if it is (i.e. transformer hum).

Does it sound like a buzz or a hummmmm? In other words, did you perhaps disconnect a wire from the RCA's while you were in there? Check that all of the wires inside are connected at both ends and nothing is floating free.

Are the tube sockets solidly connected or did you perhaps loosen one up when pulling out a tube? Does the buzz switch from left to right when you swap tubes, or is it in both channels?

Bob

I would take it to a tech if the above mentioned fail