SG System 212 Combo

[MeanMrMustard]

Got this in for repair in my new shop and couldn't help but share here. It's a hybrid SS/tube combo. SS preamp and a pair of 8417 tubes for the output. PI is a 12AX7. This is one of the dirtiest examples of an amp that still functions I've seen. I told him to consider himself lucky because it's a nightmare waiting to happen. Pics to come in a few from the phone....

[MeanMrMustard]

Pics....

[xtian]

Yes! Beautiful amp! From the same folks as AIMS?

Anwyay, first stop is outside with the air compressor and facemask...unless you enjoy breathing other people's skin flakes and dust mites. Yummy.

Not as bad as the rat poop models I've had in the shop...

[xtian]

I love the big knob on the right: 300-700. Bake, roast, broil.

[tictac]

When I was 14 a good friend bought a 212 SG amp like shown in your pictures that came with a Trini Lopez Gibson guitar...

That was the first electric guitar and amp I had ever played and it was total guitar heaven to me. The phaser shifter is awesome! China Grove in a box.....

TT

[MeanMrMustard]

LOL! They are lovely stove knobs. Wish I could find some to replace those missing. I need to go get me a compressor.

As I understand it, Gibson owned this company. He also brought in a Lab L7 and said the same of it. I do like these AlNiCos in it. Nice sound. He wants to mod it for other output tubes since the 8417s are expensive and rare. They don’t seem to be doing too well. Badass tubes that, according to the RCA bible, will do 100 watts in a pair. I thought it was bullshit. I’d never seen or heard of these American KT88s until this thing came in. The more you know....

[MeanMrMustard]

Oh and the phaser doesn’t work

[BobSimpson]

These were a POS ( IMHO ) even for their day.
Even worse the Lab amps, if that was possible.
Nowhere near the quality or sound of an AIMS anything.
Good luck cleaning this one up.

Bob Simpson

[MeanMrMustard]

Tell me what you really think Bob. Just kidding. They’re just pretty cool looking and I do like the way the speakers sound. I get paid when it leaves. Cool tubes those 8417s. Magnum.

[Andy Le Blanc]

I had one of those... the iron is alright... 8417 got me into KT88/90/100/120... I think I remember that they were one of the last USA tubes to be developed, a bit flaky for quality ... might still have the brochure and maybe some knobs.

[BobSimpson]

Hi MrMustard.
I have to admit to a bias.
I worked part time running parts and amps to and from AIMS to Arizona Music Center in must have been '73 or '74.
I was just a kid.
But I was playing too, and the SG's were always the back line amps at clubs.
Usually, the only thing that worked was the built in Maestro phase shifter.
Heavy as hell, and the flight case exterior never seemed to protect anything...
Good luck with it.
Bob Simpson

[MeanMrMustard]

Andy, if you find any of those knobs and are interested in selling, I’m sure my customer would be interested. Thanks for the info. I did like the iron when I first pulled the chassis. And I remember thinking that the 8417s must’ve been late production because I’d never seen or heard of them. Had a look and that’s the last tube listed in my RCA tube manual.

Bob, no worries. I thought it was pretty wacky when it came in but definitely has that appealing cheap oddball factor. The reverb kind of works. It’s pretty weak. No go with the phaser. He just wants it working to make good sound.

I’ve just about redone the whole power supply for the tubes as well as the bias circuit. I’m attempting now to get the bias voltage down for the bias. I’m installing a pair of JJ KT77s since I have a few pairs right now. They sound great clean.