degx1000: Modding this with a SMPS would be a terrible idea. This amp's linear power supply and huge transformer is what provides the amazing performance.
willcycle: If you are serious about getting this unit, PM me, give me your address, or at least give me the city and state, and I'll tell you what it will cost to ship. I don't know if FedEx or UPS will ship something this heavy, or whether I'll have to use a common carrier. Remember, while the unit did briefly work, it is being "given away" (in quotes, because you will have to pay $100+ for shipping) because it is not working at the moment.
My guess is that someone who has worked on these before will have an idea what to do. The fact that the green light is not on, and the fact that both channels were working and now both are not, gives me quite a bit of hope that there is some protection circuit that kicked in and that replacing that fuse, thermistor, or other crowbar circuit will get it working again.
I want to give away my Audio Research D-52 power amplifier.
It is pristine and has been sitting in its original shipping box for thirty years. My next-door neighbor gave it to me when he moved in the late 1980s. He used it for a couple of years to power two planar speakers.
It has been sitting in my shop for all this time, so it has not been exposed to any temperature or humidity extremes. However, it has not been used. Yesterday I decided to power it up. I briefly thought about borrowing my friend's Variac, which I use when I repair other people's amps (especially their tube amps), but didn't bother. So instead, I planned to power it on for 2-3 seconds, turn it off, and then repeat a few times to re-form the capacitors.I attached a CD player and some 4-ohm speakers, powered it up, heard the expected small power surge and then, just as I was going to turn it off, I heard beautiful music, but before I could hit the off switch, the music stopped. I waited 30 seconds, turned it on again, but got no other signs of life, and the green power light on the front panel was not lit. There was no smell or any other sign of self destruction; it simply quit working.
I briefly looked inside and did not see any internal fuses. The external fuses all looked OK to me, although I didn't bother to bring out my multi-meter to test them.
I am not interested in this amplifier at all. My main system uses two Altec 604 speakers and they are so efficient, I can drive them with a transistor radio. I don't need this kind of power.
I don't have the time to troubleshoot it, and the caps (the most likely issue) are too exotic for me to tackle.
If anyone wants it, all they need to do is pick it up (California central coast) or pay for shipping.
John Meyer
Carmel, CA