early 60's 6g2 brown Princeton circuit

[mort]

Just fired up a fresh build of this circuit and need a little nudge in the right direction.. Getting great guitar sound and the vibrato works, but there are a couple minor issues.

Even with the intensity and speed all the way down, there's some crackle/distortion at the peak of the pulse. I know the effect is going to be audible even when turned all the way down, but this is unwanted noise not just normal "swell".

And also, when I insert a shorted rca plug end into the footswitch jack, there's a loud BRBRBRBRBRBRBR noise instead of just turning the effect off. Seems all is wired correctly but I'll keep double checking... thoughts?

note: the one deviation from the schematic was that I didn't have a .005 for the tone pot so I subbed in a .002

[loudthud]

Edit, Enzo is right, The shorted plug should turn the tremolo off. Check the wiring until you find the mistake.

[Enzo]

You sure, LT? In this one the FS grounds the phase feedback loop in its center.

[mort]

found that if the V2 P2 grid wire is moved away from the footswitch lead then the distortion at peak vibrato goes away.

Still looks like all wiring is correct, but still getting loud noise when footswitch jack is grounded.

One other difference from the original circuit is that I used an OT with 4/8/16 ohm taps and wired 3 individual [open] jacks and connected the NFB to the 4 ohm tap. I don't think ths has any bearing on the situation but thought I would mention it anyway.

[mort]

I'm not sure if this is normal or not, but I'm reading 4.8vac on the footswitch lead. Is that what I'm hearing when the footswitch is grounded?


It's also got 0-2vdc swinging back and forth (this part I would consider normal).

[loudthud]

I'm not sure if this is normal or not, but I'm reading 4.8vac on the footswitch lead. Is that what I'm hearing when the footswitch is grounded?

It's also got 0-2vdc swinging back and forth (this part I would consider normal).

That sounds normal. Do you have a good ground on the speaker jacks?

[mort]

That sounds normal. Do you have a good ground on the speaker jacks?

The sleeves are all connected together and grounded through the bodies, all of them wrenched very tightly.

[mort]

Just wrapped up the footswitch jack issue. Installed a shielded/grounded lead to the V2 P2 grid and the noise went away. Fender never used one and my layout is very similar but for some reason it was picking up garbage.