New (old) amp day... help me date this SVT

[NickFromNY]

Was looking for an SVT type amp and came across this locally. Some rust on nuts and on metal screen in back but functions great and in not bad shape. Was used as a prop on the show Vinyl. How can I date this amp? I belive it is a 1970s head. Going to have it serviced and enjoy the goodness. Not bad for $400, I think.

 

[Dave W]

Sweet!

 

[coreyfyfe]

Nice score for the price.

Would be 75-79 with that graphic layout, but you'd have to check internal component and transformer date codes to get more specific.

 

[NickFromNY]

Anyone know a good bass amp tech on Long Island I can bring this too?

 

[NickFromNY]

Opened it up and it is all rusted inside. See pics...

Is this salvageable?

 

[JimmyM]

Seen working old SVT's with more rust than that. Might be able to clean some of it up. Not sure what to use on transformers, though I'm sure someone will. Cool score!

 

[NickFromNY]

Thanks, @JimmyM I was hoping you'd chime in.

 

[NickFromNY]

I've done some reading about cleaning them. I am always nervous about what I can and can't touch inside old tube amps. I don't mind doing the work myself if someone points me in the right direction. Going to take the amp in for a tune up, but would like to save money as much as possible

 

[JimmyM]

No reason you can't clean most of it yourself and let the tech do the hard parts.

 

[Bill Whitehurst]

If you scored that for 400 beans and don't have to put more than a hundred or two into it
to make it 100% functional and safe, you have done well.
At a minimum, I'd clean out random debris, clean sockets, plugs and pots and recap it.

It would suck to find out it was used as a prop because that was the most it could still do.
Have you powered it up?
If it has sat around for years, that could be exciting.

 

[two fingers]

Yeah rusty transformers is no big deal at all.

Cool amp!

 

[beans-on-toast]

This is how I deal with rust like that:

First of all, some rust on a transformer is fine. It’s an insulator.

Be very careful. Do not wire brush the plates. You do no want to scratch the transformer plates. As gently as possible, remove loose rust by brushing with a cloth. Then stabilize the rust. Some people use an oil based polyurehane or a rustoleum type paint. I use either Red Insulating Varnish and Super Corona Dope. Not healthy to breath the fumes when working with those products. Good ventilation is important.

4226 - Super Corona Dope - MG Chemicals | MG Chemicals

4228 - Red Insulating Varnish - Insulating Coatings | MG Chemicals

Dab it on to seal the transformer. Sometimes I’ll first apply a rust stabilizer, then the dope.

I usually replace all the jack nuts and washers with switchcraft parts. They are available from mouser.com. They are not worth cleaning. The plating come off very easily, even with some cleaners.

 

[singlemalt]

Did you find a date of manufacture while you were poking around in there?

Looks like a great score.

 

[petey293]

Have you tried taking it to a nice restaurant?

 

[NickFromNY]

This was on one of the transformers...

 

[NickFromNY]

The amp works... played it earlier tonight... a few buzzes and crackles here and there.. definitely needs a tune up

 

[coreyfyfe]

Those numbers don’t help but from the rusty transformer picture you can see the lower row of numbers has the EIA code for electrical windings (682) who made the transformers for ampeg. 682 534 would be 34th week of 75 so the amp was likely late 75/early 76.

 

[bobyoung53]

You got a very good deal, I regularly see those going for 1000 (usually higher) and up on ebay. I paid 500.00 for one of mine 17 years ago and 300.00 about 15 years ago that needed workl (in Peru) I have two of those, one's a 76 and the other's a 77 (from the filter caps), one is in really nice shape and the other has ahem, a patina like yours, they both sound great and work well. I recapped both of them about 15 years ago. I bought one of them in Lima, Peru and it had surface rust everywhere, it gets very humid there in the winter. Those heads last just about forever with a little care here and there like all Ampegs.
What the heck, I guess i have to put that picture in again.

 

[JMacBass65]

Nice score! I bought a '76 back in the mid 80s and it's still going strong.

 

[Bim1959]

Fantastic price!!! I had one identical to it (my avatar pic) that I sold 3 years ago for over 3x as much. That rust wont be too hard to remove.

Enjoy!!!!!