Calrad SA-30B - need schematic.

I recently acquired a very clean old Japanese Calrad SA-30Bintegrated stereo tube amplifier.

There's a good bit of information on the web posted by "Triodeguy" (Richard F. Sears) about the SA-30, but I don't know how it differs from the "B" version.

Mine needs work. One channel is distorting pretty badly
and maybe, after it's fixed, I can also implement some suggested by Triodeguy.

But before I do I need to know what I'm doing and for this I need the schematic or at least a good understanding of how the 30 differs from the 30B.

If anyone can point me to where I can get a schematic, I would very much appreciate it.
Start working on swapping tubes first, than inspect/replace visually all DC caps for bubbling(an electrolytic cap tester might be handy to you), leaks, dark burning spots, resolder joints with fresh solder and maybe you won't need any schematic. Having schematics for 30 displayed, ID the matching elements first(which I believe there will be most of them) and than you'll know what's different.