Fender SuperSonic Squealing

CianRyan

Hi all, at the title would suggest I'm having an issue where in my amp is squealing like mad intermittently.
Now I'm quite technically retarded but to me it sounds like the squeal only starts when the tubes are pushed, it wouldn't just start out of nowhere but say when I've my overdrive on and I pick hard for a dramatic bend or what have you.
I was also thinking it could be the speaker but I think a worn out speaker would be more of a fluttering sound?

I'll get a video so you can see it in practice but any idea's with that description?
Thanks in advance, lads.

Oh, it's the 60w 1X12 combo.

zafo

It may be micro-phonic squealing as tubes are on their way out, you could try poking at the tubes with a chopstick (other hand behind your back) and see if that makes it worse/better. That would also tell you what tubes are at fault.

CianRyan

Cool, I could try that. What am I looking out for, will taping the dodgy tube cause it to squeal?
What about my hand behind my back? Chance of electrocution? :eek:

Here's a video.

https://www.youtube.com/watch?v=bg2oTHHsdxk

zafo

Sounds like something in the preamp tubes to me but I'm not an expert on amps so best take it to a tech but yeah the tapping with produce squeeling from the offending tube.

Not really much chance of electrocution with the tubes but it's good practice to keep one hand behind your back or in your pocket when poking around an amp. Chopstick is used as wood is non conductive so you won't get shocked even if you do happen to touch something that's live.

Squidgy Black

Definitely sounds like a microphonic preamp tube, or else a power amp tube on it's way out. If I was you I'd just do an entire retube if you have the cash for it.

CianRyan

Had a look see but fender thought it smart to encase the tubes in metal cylinders. Great for protection I guess but awkward in this situation.
All in, I guess I'll just retube it with something tasty. I wouldn't mind a bit more grunt in the burn channel and an earlier breakup in the bassman.
It'll be after Christmas though... Bloody Christmas!

Nice one, lads.

zafo

All pre amp tubes should be in metal cylinder/shields that come off easy with a push in and slight twist of the cylinder. I don't think fender do it differently but either way just tapping on the shield should work too so turn on the amp and tap the shields/cylinders and the other tubes and see which if any cause the squealing.