Hey guys, I'd like to build a 400W powered amplifier for small signal input from a microphone source to amplify vocals out of PA speakers. I have found the following schematic and I have two questions for whomever is willing to help: 1) Is this circuit adequate for the application? 2) What type of power source should I be looking for (current output) for the +70V and -70V connections? Thank you so much for your help. Andrew http://www.geocities.com/pa_schematics/400MOS.gif"