In regards to the 800RB,I bought as a project. Took it a Gallien Krueger service tech,recommended by Louis,at GK. After disassembling,traced problem to&replaced parts listed in the High frequency Amp,adjusted Bias,and tested. Replaced,Output Transistor,and resistor. Wasn't as bad as I thought it would be. I know I took a gamble,but I now have a 800RB,in good working condition. I think I will hang on to this one. After the servicing,and everything,less than $200.00, for a nice 800RB.