Audioprism Mantissa tube preamp buzz


Hello everybody, I've just re-tubed this preamp and after hooking everything back up I have a loud buzzing coming from the speakers. I tried a different amp and putting the old tubes back in but I still have the buzz. I've narrowed it down to preamp being the source of the problem. This piece also has an outboard power supply. Is there anything that I might try to fix the problem or should I just take it to a tech. I appreciate any suggestions. THANKS
superdav

Showing 1 response by sogood51

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