Sunn SG260 guitar amp?

[bhikudave]

Does anybody know about this amp?
I picked one up for a decent price but can't seem to find any documentation. It's got some buzz going on and could likely use a cab job.
IT seems very similiar to the SL 260 here except the layout on the face left to right is inputs, bright switch, EQ knobs, Channel A, Channel 2 Drive, Channel 2 Volume, Reverb, Master volume:
http://www.shopgoodwill.com/auctions/Sunn-SL-260-Guitar-Amplifier-16918818.html

Also on the back of mine the foot switch takes a 4 pin female connection (like a beta lead)

Anyways I can't find anybody who will work on it without a Schematic. Any Info would be appreciated.

[bhikudave]

Here are some photos

[loudthud]

Thanks for posting the pics. This seems like another of the amps that never made it to a catalog. It's very similar to the SL260 with the controls in slightly different order. The speakers in your amp may have been re-coned judging by the scratches in the labels. Also the redish wires don't look original.

[bhikudave]

Thanks for the info!  I finally found a foot switch that will fit the thing, but unfortunately channel A is dead.  The reverb on this thing has big swells and is really spooky sounding. The speakers need some love as they distort at lover volumes even under low gain settings.  I really wish I could find more info because I'd love to get this fixed.

[loudthud]

The closest schematic I have is the SB160. The power amp is probably the same, it's not very conventional. Technical description: Power stage gets signal off of a dual opamp's supply rails. Some Ampegs do this.