6G11a vibrato too fast.

[pintail78]

I want to slow it just a little. It looks like changing the .02 (hard to read?) that goes to pin7 of V3 would work. Is that correct and what do I change it to? Thanks.

[soundguruman]

Just a few more details would be helpful.
Like what amp? and what schematic are you looking at?
Dammit Jim, I'm an amp tech, not a psychic friend network.

[Jazz P Bass]

The amplifier is a Fender Vibrolux.
You could try changing the 100K tail resistor on the speed pot.
A larger value should make the speed slower.

[soundguruman]

I think you wanna make the cap bigger not smaller, so the charge time is longer.

[pintail78]

its a 62 vibrolux 6G11a. so maybe a .03 on the cap or something like 130K on the resistor?

[Enzo]

There are three feedback caps, the .02 and a pair of .01s. I'd increase the .01s to also be .02uf. You cam replace them, or slap a couple more .o1uf in parallel with the existing ones.

The 100k resistor might help, but I worry that 100k is a very small part compared to the 3500k of the speed pot.

DOubling those two caps is my go-to for slowing Fender tems.

[pintail78]

There are three feedback caps, the .02 and a pair of .01s. I'd increase the .01s to also be .02uf. You cam replace them, or slap a couple more .o1uf in parallel with the existing ones.

The 100k resistor might help, but I worry that 100k is a very small part compared to the 3500k of the speed pot.

DOubling those two caps is my go-to for slowing Fender tems.

I doubled the .01 caps to .02, it slowed it some, I wonder if i go to .03's or .047's if it will slow some more? changing the .02 or the 100K resistor didn't do much at all.

[Enzo]

Each one of those RCs is a time constant. Changing a single cap or resistor won't do much. Sure you can increase the cap size some more. DOubling a .01 to .02 should be about the same thing as raising one of the 1 meg reistors to 2 meg.

[Jazz P Bass]

Try .047uf.

[pintail78]

Ok, doubling the .01 caps worked good in my 62 vibrolux, slowed it perfectly. I did the same on a 62 pro with the same vibrato circuit and it changed it a little but not very much, I may need to try the .047's as suggested. Thanks for the help everyone.

[Enzo]

At the same time, I don;t recall if we mentioned it, but the existing caps need to be healthy. Ancient caps may be part of your issue.