Twin Reverb Reverb buzz?

[NorCalTuna]

I worked on a twin for a friend that came out amazing, except for a minor buzz that seems to follow the reverb. The amp is a Silverface master volume with the pull boost, which when pulled seems to diminish the buzz slightly.

I pulled the reverb return cable and it didn't do anything, I pulled the reverb send cable (and tube as I didn't want it to not have a load) and it went away entirely. Is this what the 560pf cap from the plate to gnd is supposed to suppress? I didn't test this cap, but it was there.

I'm gonna try a new tank and cables since I have one on hand... so i'll report shortly!

thanks forum~

[52 Bill]

Is this one of the models that used some of the reverb drive signal to overdrive the preamp?

You could be getting some signal bleed coming through the pull switch or related wiring. Check all of the grounds on the shielded cables.

[Euthymia]

The first thing I check when I see an old Fender with a buzzy reverb is how the tank is oriented.

The tank output should be on the end of the cabinet further from the power transformer. In other words, the jacks on the tank should be facing the front baffle of the amp.

This is to get the noise from the power transformer away from the reverb pickup.

One might think that the tank is far enough away, down at the bottom of the cab, for it not to matter, but it makes a big difference in the amount of background buzz in the reverb.