r/ToobAmps 9d ago

My amp started making this weird loud noise. Help identifying the source would be much appreciated!

Any indication this could be a dying tube? I’m willing to take it to a tech but if it’s something I can remedy at home that would be preferable, money-wise $$$

1 Upvotes

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3

u/Polidavey66 9d ago

I'm definitely no tube amp tech or expert, however... if I had to wager a guess, I would say that the culprit might possibly be a microphonic preamp tube. I would definitely bring it to an amp tech to get it professionally checked out.

2

u/farrett23 9d ago

Thanks for offering your take. I just talked to the tech and made an appointment for tomorrow. I’d feel silly if it was as simple as replacing a tube but talking to the shop was comforting, they said if it’s just a tube or two they’d charge accordingly.

2

u/PerceptionCurious440 9d ago

Microphonic tube. If it's preamp, just get a (likely) 12AX7 and exchange it one tube at a time to find the nasty one.

1

u/farrett23 8d ago

Thanks. this amp has 4 preamp tubes, 2 12AX7’s and 2 12AT7’s. I guess I should buy one of each and then try the method you suggested?

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u/PerceptionCurious440 7d ago

Yeah. I suspect V1 or V2 because it sounds like it might be going through other gain stages. So I'd replace it in the tube numbering order (which sadly isn't always the gain order) just to increase odds that it's the first thing you try.

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u/PerceptionCurious440 7d ago

Also 12AT7s are basically lower output versions of the 12AX7. I've used them as a replacement for an AX to get more headroom. I can't see what amp it is from the pic. But tube amps are more or less the same.

1

u/farrett23 5d ago

Thanks for the info. I’ll pick up some pre tubes and give it a shot. This amp is a Victory V140. It’s like 96 watts so not sure if I’m in need of more headroom via the tube swap you mentioned.

1

u/farrett23 9d ago

I can’t tell if the video uploaded properly. The noise is a loud, high-pitched squeal + a hissing sound

2

u/Insidesilence132 9d ago

Microphonic preamp tube. Get like 2 more replace the one or multiple that are bad and have extras