Dynaco ST-35 Hum in One Channel

[petertub]

Change what ? There is no Se diode in St35 !!

 

[rayma]

The HV diodes for the B+ are certainly not selenium. And there is no bias supply diode, since there is no bias supply,
the Stereo 35 being self-biased

 

[MarkC568]

Also replace the oversize pcb capacitors with ones that fit on the board properly.

Got my Digi-Key order today, so replaced the oversized 1990-era "WonderCaps". Much better!

Also figured out the PAS3 hum issue. The PAS chassis is designed to connect the output RCA grounds to the chassis, but this can sometimes cause a ground loop.

Isolating those RCAs from the chassis eliminated the right channel hum. It's back to being delightfully silent.