Sansui AU - 919 Thrift Store Find

Pretty amazing I found this tonight in nice shape for $50. It looks like it took a bump at some point in it's life because the face plate has shifted about an 1/8". Sounds worse then it is. A couple minor scratches on the top. Works great. Really an amazing find for the money. And it is a great Amp. I have had some of the earlier Sansui stuff like the 9090 Receiver, and was not very impressed. But this unit is an impressive keeper.
Any insight on any of the controls, and the best way to set the Amps controls would be helpful. I am using Tannoy System 800 Speakers, and a pair of Pioneer HPM 100's. The Tannoy's are what I mainly use.