hifi engine

PS audio Model two (2) Stereo Power amp: Service manual / scheme tech notes

My brother have this for quite some time (this unit is from the 80's) and now it seems that one side is faulty (DC in the output speakers burned etc...)
This seems to be one of the first power amps PS audio presented in the 80's. It should be 55 WPC and it looks like a small black cube with one on-off square switch and one red LED as an indicator on the front panel Blue lettering "PS model two" are also notable. power transistors are MJ 15003 and MJ 15004.

Kindly upload any info you have on this... I searched the web without success...
You may reach me at: harel.shachar@gmail.com
TNX very much and have a nice weekend!