Counterpoint SA-3000 Preamplifer


My preamplifier now has a his that I don't know where it's coming from.  Does anyone know what might cause this issue.  
Also does the tubes need to be biased? if so, does anyone know how to do it?

Thanks
chan-audio
The SA3000 has a single tube line stage.  Each triode in that tube is cathode-driven with a JFET input stage and the plate goes to an ancient old OpAmp as buffer.
The phono is also rather similar.  I would not spend much on it.
Thank you all for your suggestions.
I've hired a electronics' repair company to evaluate my SA-3000.  I'll let you know of his findings.
Counterpoint has a great reputation. Amazing gear. Get her upgraded, , replace caps / tubes. Enjoy another 20 years!

great stuff!
if it is in both channels, it is power supply related... if it is in one channel it’s a tube, resistor, or capacitor.