SOLVED Frost Drive Squeal

[BuddytheReow]

Finished up a frost drive with the Sherbert mods. When everything’s dimed there’s a super loud, high pitched squeal. Anybody had this issue? I’m assuming it’s coming from the gain section since it goes away when I dial it back along with the Hi Cut. I’ll probably increase C6 to 47p or maybe greater. Am I heading in the right direction?

 

[BuddytheReow]

Anyone?

 

[Robert]

It's been a long time since I built this one, and I'm not sure if I ever tried the various mods...

Do any of the other controls affect the pitch of the squeal?

 

[BuddytheReow]

Only the tone control and the 2 trimmers affect frequency of the squeal. In terms of the volume, I notice gain, level, mids, and high cut are the culprits. That’s with everything maxed out. Once the gain knob is turned down past 3 o’clock we’re good. I mean, it’s a tubescreamer and I plan more on stacking it with a rat or a muff so max gain isn’t really a deal breaker. It would just be nice to have full range of everything.

 

[Robert]

Does the squeal stop if you turn the guitar volume all the way down?

 

[benny_profane]

I’m assuming you’ve verified all the component values? This build has a lot of subs going on between the variants and the scaling to accommodate an in-production pot.

 

[music6000]

I’m assuming you’ve verified all the component values? This build has a lot of subs going on between the variants and the scaling to accommodate an in-production pot.

Yep, is it a 10K or 100K dual mid pot with th matching resistors?

 

[music6000]

Anyone?

Wth all the variables for this Build, a good picture of the PCB would be great.

 

[BuddytheReow]

Here you go. Like I said I did the sherbert version of this. I subbed a A1M for the D1M since they’re hard to come by. The 33p I subbed a 39p since that was all I had. The dual pot is a C100k and I (think) I altered the other components based on the build doc.

 

[music6000]

Does the squeal stop if you turn the guitar volume all the way down?

What he said above?
Everything looks good with the Resistors & Caps!
Has this been boxed or is it out of the enclosure test???

 

[BuddytheReow]

I’m gonna box it up this afternoon and report back. I drilled the enclosure maybe an hour ago

 

[BuddytheReow]

Squealing is fine, but now the gain pot doesn’t do anything. It sounds fully maxed out. My DMM confirms. Ugh!

Edit: taking it back out of the enclosure and the squeal comes back and all the pots work fine. This tells me there’s a short somewhere….

 

[BuddytheReow]

Back in the enclosure and now everything works. The problem? Heck if I know. My guess is there was a short somewhere from tightening some of the nuts too much. I guess I’ll mark this solved?

 

[music6000]

Back in the enclosure and now everything works. The problem? Heck if I know. My guess is there was a short somewhere from tightening some of the nuts too much. I guess I’ll mark this solved?

I did notice the Tape under the Dual pot, I use a Round self adhesive rubber pad myself, too many issues have been from Tape after being tightened!

I thought the Squeal was the cause for being out of the enclosure,
It's amazing how much radio interference you can get too when it's out of the enclosure!
You can change stations just by touching different components.