This was my latest project. I was given This Onkyo TX-SR806 receiver that had considerable digital noise in the background of the audio. It would fade out after running a bit, which led me to thinking this thing could be repaired...and it could
In it's original home, it was installed in a rack cabinet without any cooling around it, powering 7 speakers. It literally cooked itself do death! I found several bad metal film capacitors on the digital board, and I replaced them with regular electrolytics. I then installed it in my own rack cabinet with two other "rescues". A Crown Com-tech 800 I got from an old tower records store that went out of business, and a Crown D300 that came out of our boardroom at work, and had heavy distortion in it. The D300 needed two IC chips that cost $5.00 each.
Typical of home-theater receivers, they do not have enough kick out of the power supplies to drive all audio circuits to their maximum output. The output of this amp is 100 watts X 7 channels, but the power supply only supplies 500 watts, so with all 7 channels singing, it runs out of juice before it meets max power. I only have the system set up as a 5.1 system, but the amp supports 7.1, but in my den, it's not really any room for the side speakers, so that helps. I'm using the Com-tech 800 amp to drive the front left and right speakers. The D300 is bridged and driving a car stereo subwoofer...an old Polk Audio C4 that has 4 6X9 woofers in it.
The amp in it's new home there is quite happy. With some of the load shared with the other amplifiers, and gap between components, and and exhaust fan at the top to draft air around it, this receiver is running comfortably cool during even the loudest action movies! Fidelity is awesome and I"m liking the Dolby TrueHD audio...definitely a step up from my old Lexicon DC1 with Dolby AC3...and it met the best price of all!