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Thought I'd resurrect this thread to give an update: The amp went to the shop three times. First to have the speakers rewired properly, second to be retubed with a supposedly "new" quad of Svetlana 6L6-GC's and biased accordingly, and third when the amp wouldn't stop blowing its 6 amp fuses and finally blew the internal fuse (reason: one of the 6L6-GC's was supposedly cracked, rendering it useless and causing the fuse issue, according to the tech). On the third visit, I had him reinstall the Sovtek 7027A's that came in the amp when I bought it.

Sounded awesome for a few weeks, and then......

I was playing one day when I started to notice behind me the amp started producing the most fucked up noise I've ever heard. Turned around, and there was flame coming out from behind the power and standby switches! Turned it off, took it BACK to the shop (thankfully, this guy gives a 90 day, no-questions-asked warranty on all amps he repairs, or I'd have been shit out of luck the first two times it went in for repairs). Told the tech to do whatever it takes to get it into 100% reliable working condition, whether that means a full cap job (he claims he went through every component the first time it came in for repair, including the filter caps, and that nothing needed replacement), replacement output transformer (hopefully not), any new power/preamp tubes (affordable, but I hope they are still okay), etc. I'm starting to doubt his credibility at this point, but...then, he's done fantastic repair work on countless amps for myself, my bandmates, and numerous friends and acquaintances in the area. Plus, there really aren't any other options for amp repair in this area. So.....yeah.

Times like this make me want to actually personally learn as much as I can about tube amp maintenance and repair. If the VT-22 wasn't such an amazing sounding amp when it IS fully functional, I probably would've thrown it in the Ohio River by now. Never owned a more unreliable piece of equipment. My fingers are crossed that it is repairable.

That sent a shiver up my spine. You must be pissed / frustrated. Now I am wondering whether to get my VT-40 checked out. It hasn't missed a beat but who knows.

I wonder if your guy knows what he is doing, he is just up against something weird or not obvious that existed when you bought the amp. It takes some serious current to generate that kind of heat and Ampegs certainly pump out the current.

Anyway if it was my amp that was doing this I would try to get to the bottom of it too rather than try to find something else. These are killer amps.

Good luck and let us know how it works out.

have him install a fan to cool the output tubes. probably needs proper screen resistors. probably drawing too much screen current and burning the output tubes.

fan on tubes
1K 5W screen resistors, one per tube
check filter caps

that'd be my first course of action. playing with the volume knob very high, like above 80% or so? definitely put a fan on those tubes.

you might wanna bias it a little colder, maybe more like 60% of max static dissipation. that could help tube life too.

I do tend to play with the volume pretty high.....the master is typically anywhere between 2:00 and dimed, while the volume (pre) is usually at about 10:00. Maybe I could just keep a small fan around and place it in the back of the amp, pointed up at the tubes when playing at high volume, rather than having one permanently installed.

Tech still hasn't called me back with a diagnosis (apparently his shop has gotten an influx of malfunctioning amplifiers lately), but when he does, I will keep your suggestions in mind Scott, and pass them along to him.

Grabbed another VT-22 (Magnavox era, non-master volume model) for $400 today on Ebay, as it now seems wise to keep a second one around just in case.

The issue apparently was that the Standby switch had finally given out. Swapped the Polarity switch with the Standby (polarity was unnecessary since the amp has had a 3 prong plug installed). I've played the amp at stage volume for the last few nights, for several hours, and it seems to be holding up great. On general principle though, I plan on taking the advice given by you guys and having the caps replaced, new power and preamp tubes installed, and I will definitely look around for a small fan to place in the back of the amp.

Snowblinder wrote:Grabbed another VT-22 (Magnavox era, non-master volume model) for $400 today on Ebay, as it now seems wise to keep a second one around just in case.

This part blew me away.

I don't know if it's a good deal for this amp or not, but that's fucking cheap for an amp. I wish I could get a vt-22 for 400$. Especially now that the dollar is so low.

It seems pretty good to me too ($400 I mean). I've seen them go from anywhere between $400 up to $700 lately. Same with the V-4, V-2, et.al. As I said earlier in the thread, the one I got initially (i.e. the one that has needed all the tech work) was $350, and I've put about $100 maintenance into it so far (thankfully, my tech's warranty has covered everything after the initial repair, though I admittedly feel somewhat shitty about him sinking labor into the amp and not getting paid for it, but...hey, what can you do?). Craigslist is the best place to look. I've seen more than one of these on there in the last few months going for as little as $300.