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#1 2008-02-12 03:54:48

snowblinder
Member
Registered: 2007-12-12
Posts: 50

VT-22 Problems, Continued:

I've posted here regarding a VT-22 I picked up a few months ago. Originally, when I initially purchased it, the speakers were wired incorrectly, resulting in very minimal volume. My tech fixed this. Then, after retubing it with Svetlana 6L6-GC's and biasing accordingly, the amp was popping fuses left and right. Eventually the internal fuse went. Found out the tubes I had purchased were the issue: one had a small crack at the base. Put the old 7027A's back in and all was good. The amp never sounded better. Until today:

I was playing the amp at practice, at a high but still reasonable volume (master at 3:00, pre volume at 10:00). Sounded amazing, when....the amp suddenly started producing a loud kind of oscillating hum. As I looked back at it, I saw flame coming out from behind the standby switch, so I immediately switched the amp off and unplugged it.

The last time I played it, before this happened, I did notice a faint hum coming from the amp when it was in Standby mode. This should have been a red flag, I know, but I didn't think much of it at the time. Now...it's going back to my tech, but before I take it.....I figured I'd bring my story here and try to get some opinions on what the problem may be. It really is a shame because tonewise, this is the best amp I've ever played. I love it. But it has been in the shop three times now since I bought it a couple months ago. Unacceptable. Time to throw in the towel and just get a different amp?

I wish I knew more about the technical aspect of these (or any) amps. But I don't. So, any help would be greatly appreciated. Thanks.

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#2 2008-02-12 05:12:42

hangman
Banned
From: Seattle Washington
Registered: 2006-09-04
Posts: 1848

Re: VT-22 Problems, Continued:

wow,  you've been having some unfortunate luck with your Vt-22!

one thing to keep in mind is that these are old amplifiers,  and for a guitar amplifier of this time period were reasonably complex.

there are any number of things that can cause problems,  but 99% of them can be avoided by keeping the amplifier maintained.  example: anybody who has an old Vt-22 or V-4 with the original filter caps is asking for trouble. 

as much as we'd like it to,  maintenance doesnt always keep up with problems.     sometimes problems are difficult to foresee.

If you're concerned,  talk to your tech.  tell him you would like to make the amp as reliable as possible.  tell him what you want to expect from the amp.   He will tell you if he thinks it is possible

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#3 2008-02-17 03:38:19

snowblinder
Member
Registered: 2007-12-12
Posts: 50

Re: VT-22 Problems, Continued:

Yeah, it sucks that this amp, which I got for such a great price to begin with, is becoming such a hassle. Thankfully, the tech I have guarantees all of his work for 90 days. Upon the first go round with this amp, he supposedly went through the entire thing and checked every little detail to make sure nothing needed replacing or other maintenance. So, all of these problems I'm having, he is being generous enough to handle for no cost.

I told him today I really love this amp (I do, it's unlike anything I've ever played, and has sparked a mild obsession with vintage Ampeg gear) and that I will basically pay whatever it costs and wait however long it takes just to get the amp back into reliable, 100% working order.

I'm hoping the issue is the filter caps. I was intending on replacing those pretty soon anyway, as I have no idea if they are the originals or not. Power tubes (Sovtek 7027A's) are in great shape as far as I can tell. Really hope it can be fixed. Wish I knew more about the amp so I could just repair it myself.

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#4 2008-02-17 20:07:06

hangman
Banned
From: Seattle Washington
Registered: 2006-09-04
Posts: 1848

Re: VT-22 Problems, Continued:

snowblinder wrote:

Really hope it can be fixed. Wish I knew more about the amp so I could just repair it myself.

I think one could say that about any old tube amplifier.  some are easier than others I suppose.

keep in mind that it probably worked great for 30-40 years, with only the occasional tube needing replacing.
you'll get it up and running, and it will be a tank just like it was when it was built.

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#5 2008-03-12 20:49:02

snowblinder
Member
Registered: 2007-12-12
Posts: 50

Re: VT-22 Problems, Continued:

Amp is fixed. The tech said the Standby switch had just given out, so he disconnected the polarity switch, and swapped them. Cranked the amp for a few days and it sounds really nice. It seems to have a lot more clean headroom now as well, which had been a slight concern from the beginning. I don't know how the clean headroom could be correlated with the Standby switch, but....whatever. This is why I'm not an amp tech, haha.

I bought a second VT-22 the other day (non master volume model, Magnavox era) for $400, just to ensure that I always have a backup. Can't live without one of these amps.

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