Tremolo oscillation squeal on Brownface Vibroverb build

[kanderson70]

Just built a 63 Brownface Vibroverb and everything is working great and sounding good EXCEPT.... with the Tremolo on and the intensity set over 3 or 4, I will get an oscillation/squeal.
My first thought is to replace the .01uF going to the Intensity pot.... or maybe the intensity pot itself?
I won't have time again to troubleshoot until next weekend, but wanted to get some of the expert's perspectives from you guys.

What are some of the things I should look at?

[xtian]

Lead dress on the wires running to the tremolo pots is critical. Push them around with a chopstick while running. Post photos if you can't sort it out.

[kanderson70]

Lead dress on the wires running to the tremolo pots is critical. Push them around with a chopstick while running. Post photos if you can't sort it out.

That's definitely a possibility. I know I didn't twist those two wires. Thanks I'll give that a shot.

[sluckey]

Disconnect the NFB wire from the speaker jack or board. Does it still squeal with the tremolo?

[kanderson70]

Disconnect the NFB wire from the speaker jack or board. Does it still squeal with the tremolo?

Thanks Steve... I'll try that too. Let's say it does stop the oscillations. Then what would I do?

[sluckey]

Swap the OT primary plate leads and report back.

[kanderson70]

Couldn't stand it. I had to tear into it tonight.

So I took Xtian's advice and tried the chopsticks... nothing. So I twisted the pair of wires from the Speed and Intensity. nothing.
Then I tried Steve's advice.
Bingo. Had to swap the two leads from the OT going to the power tubes.
Thank you Steve and Xtian! Working like a champ now, no oscillation squeals, and to tell you the truth... it even sounds better than before (even without the vibrato on).

Love this place

[xtian]

Steve wins.