Strange 1200S

[Amptech]

By all schematics, is a 2000S, anyone know anything about this beast?

[EdBass]

All of those big amps, as well as the two output tube amps are almost identical, the only differences are minor tone stack variances. Of course some of the "guitar" amps have reverb and tremolo circuits added as well.
My 2000S's have punchouts on the chassis under the faceplate that would have been used for reverb and trem had they at some point during production been destined to be guitar amps rather than bass amps.

[Amptech]

Thanks Ed, I figured as much, I was just surprised to see that output transformer.  I too have the punch outs for additional knobs, but the faceplate covers them.  I went thru the 2000S schematic, and it seems component for component, it seems that this has a 2000S circuit.  Could this have been a mistake from the factory?  I'm trying to post additional pictures, but seemingly with no success.  Thanks again  Bill

[loudthud]

If the amp just has Volume, Treble, Bass and Coutour with no Deep switch, it's a first year model, 1968. It has a big coupling cap at the Volume control so it's like the Bass boost is always in.

[Amptech]

Well I tried posting pics of the underside, but post pics here is like a slow form of torture.. Can someone help?

[Watson]

The server is size sensitive it appears from my experiences.  I've had no issues with images smaller than 300 or 400 K but had nothing but trouble with larger images. I've taken to processing them in Photoshop, reducing the physical image size down to 1280 X "whatever" and then saving them in .jpg format using Photoshop's "Save for Web" feature to insure their size is under a couple hundred K.

[EdBass]

Thanks Ed, I figured as much, I was just surprised to see that output transformer.  I too have the punch outs for additional knobs, but the faceplate covers them.  I went thru the 2000S schematic, and it seems component for component, it seems that this has a 2000S circuit.  Could this have been a mistake from the factory?  I'm trying to post additional pictures, but seemingly with no success.  Thanks again  Bill

I can't really imagine a hand built amp accidently being built as something different, but I suppose anything is possible; early Sunn anomalies have been repeatedly documented here.
Is it labeled as a 1200S?
Another possibility is that it was converted to a 2000S front end after the fact, as has been covered the output stage is already the same.

[Amptech]

Well I'm trying Photobucket, and hoping it scales down the pics.  Here are the pics of the underside..

[Amptech]

Now we're cookin with gas

[loudthud]

The tube socket nearest the chokes looks like it arched, evidenced by the black stains on the chassis. (Photo #3) It should be replaced.

[66tele]

I found another 1200S on Harmony Central that looked just like yours.......no reverb or tremolo, no bass boost switch and had the big grey potted output transformer. A check of the 1968 Sunn catalog confirms that the 1200S did not come with reverb or tremolo that year; they were added in 1969. So you have a rare 1st year 1200S! I can't seem to find a schematic for this particular model, but it would be interesting to see if the tone stack is different from the 2000S.