Faint 60-Cycle Hum

[Paul Birkeland]

Yes.  When the coarse and fine are all the way up, it's noisiest.  I will do as you've suggested.

But if fine is all the way up and coarse is all the way down, it's still quiet?

[jtori]

But if fine is all the way up and coarse is all the way down, it's still quiet?

Not present, or very, very faint.

[jtori]

Followed Paul's and Deke's guidance and desoldered at all the points on TwoQuiet where black leads land.  These connections are now clean.  With no signal, hum is nearly inaudible until -9dB on the coarse attenuator, where it becomes audible.  At 0dB, it is as before.  So, not sure where to go from here.  I defer the the sage wisdom of the most august members of this forum. 

[Paul Birkeland]

Is this still with shorted inputs?

[jtori]

Is this still with shorted inputs?

No.  Dead quiet with inputs shorted.

[Paul Birkeland]

No.  Dead quiet with inputs shorted.

Then your amp is working properly.