I don't have a number for the transformer but it came with this:
120VAC 3 Channel Color Organ Kit-The Electronic Goldmine
Here is a drawing. The greenline and the red line are the terminals that are connected. It seems like a really weird configuation to me.
2nd Question. According the the schematic and instructions that came with it, the low resistance side is connected to the speakers and the high resistance is connected to SCR's.
The resistances I got were 2ohms and 50 ohms. Wouldn't attaching a 2ohm load to a stereo that already has speakers connected cause the stereo to overheat?