Weird 5F6A Bassman Clone problem - Treble = Volume?!

[nash076]

Hey folks, I have a weird issue and was looking for some assistance ...

Recently, I had to replace the filter caps on my 5F6A due to it blowing fuses. The filter cap replacement solved the problem, and the amp is running again, but something bizarre started happening: the Treble knob, when turned up, kills the volume.

So if I turn the treble knob toward 11, the volume from the entire amp goes dead. If I turn it back to zero, full volume, no problems. Bass, Mid and Presence all appear to be behaving properly, as are the Bright and Normal volumes.

Before the filter cap replacement, when the amp was running everything was fine. Any idea what could be causing this?

Also, if it makes any difference, my preamp tubes are all EH 12xa7's, the power tubes are Tung-Sol 5881 re-issues, and the rectifier is a JJ GZ34.

Any help or insight would be greatly appreciated.

[plexi50]

Double check your treble pot and other pot wiring

[nash076]

Double check your treble pot and other pot wiring

The wiring was correct, but there must have been a cold joint somewhere in the circuit.  I re-did all the joints in the chain from the pot to the board back to the tubes.  Problem solved.

[plexi50]

Excellentay!

[HotBluePlates]

Double check your treble pot and other pot wiring

The wiring was correct, but there must have been a cold joint somewhere in the circuit.  I re-did all the joints in the chain from the pot to the board back to the tubes.  Problem solved.

I wish Hoffman's Law wasn't right. But then I keep finding some silly wiring error I made in a new build, and then everything works perfectly.

Hoffman's Law (for a new build): If it was wired right, it would be working now.