bullittstang

Reason for the join, is this forum was mentioned to me from DIYAudio.com, where I posted for some help on a Carver A-220 and setting the bias. A friend found a working, decent condition A-220 at an Estate sale and asked me to look it over before he hooked it up to any speakers. It all checks out, all original (it appears), except for a 14-gauge plug, although it's still only 2-prong. I checked the repository and there is a Specs Sheet and Owner's Manual, but no schematic or Service Manual for this model amplifier. Like I said, it works (listening to it as I write this post) and sounds great. I only want to check what the Bias procedure is, because when I check the voltage over the emitter resistors I get 0-1mV and the heatsinks are barely above room temperature after 2 hours of playing music. I would expect there to be 10-20 degree rise over ambient after that long. So mainly want to see if this design requires special bias procedure, and what the voltage measurement at what points is correct for factory spec. Thanks and appreciate any help or comments.

Hey everyone - glad to be a part of the community. Looking forward to reading through some of the posts and getting more knowledge of amplifiers and circuits. Build and repair amplifiers (notice I didn't day design) for almost 6 years now, which started with designing and building speakers about 15 years ago.