#1
So at band practice last Saturday my Peavey Classic 50 blew a fuse. I didn't think much of it since it's used and the fuse probably hasn't ever been changed. I put in a new fuse and the amp turned on and started making this horrible humming/screeching sound for a bit, which I assumed to be a microphonic tube being exacerbated by the fan inside the amp, but then the fuse blew a second time.

Am I right in assuming that this is an issue with the power tubes, or is it something else entirely? Any help is greatly appreciated. I might be selling or trading the amp soon and I need it to be in working order.

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#3
It certainly sounds like a power tube gone bad. Hopefully that's what it is, because the other options are something in the power supply, which is a lot harder to fix.

I'd throw in a new set of power tubes, or just pull the inner two tubes, then the outer two if you want to diagnose it without buying a new set.
#4
I know this is a dumb answer but is the amp set on the right ohms for the cab?.....

My kids messed with my switch before and I blew a fuse because of that....
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#5
Quote by Roc8995
It certainly sounds like a power tube gone bad. Hopefully that's what it is, because the other options are something in the power supply, which is a lot harder to fix.

I'd throw in a new set of power tubes, or just pull the inner two tubes, then the outer two if you want to diagnose it without buying a new set.


This ^ Pull the tubes and fire it up. If the fuse doesn't blow then you have a bad tube.
#6
It seemed like all four of the power tubes were still glowing, so should I still check them?

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Solder fume huffer σƒ τλε τρπ βπστλεπλσσδ

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Electronic Audio Experiments
#7
Bump: I just pulled the outer two tubes and the amp seems to be working fine now, albeit at lower volumes thanks to the missing tubes. I'll probably order a whole new set, since they're the stock tubes from 1994 when the amp was made.

Thanks everyone!

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Solder fume huffer σƒ τλε τρπ βπστλεπλσσδ

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Electronic Audio Experiments
#8
Another bump: Pulling the outer tubes worked for a while, but the fuse blew. I'm trying it with the inner tubes pulled. What do I do if the fuse blows again?

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Solder fume huffer σƒ τλε τρπ βπστλεπλσσδ

╠═══════╬═══════╣

Electronic Audio Experiments