One output channel (the right) on this older but still excellent amp won't play during the first perhaps 30 minutes of warmup and use; then it plays intermittently; and eventually it seems to play steadily--but must be considered unreliable.
It there an easy fix, something easy to replace, or it this a "cost more to check out than it's worth" situation? Shame to toss this fine old box, but must be practical.
What do you think? (I isolated the problem to the amplifier via changing inputs, outputs, earphones, speakers, etc., and using all face controls.)
Hi Randyhath. Intermittent problems are usually the result of cracked solder joints somewhere in the circuit. No components need to be replaced - a good thing. Are you handy with a soldering iron?
Look at the transistors or components that are screwed to the heatsink (metal plate for cooling). If you can see little crack rings around the component legs, you have found your problem. Resolder the joints and you should have a reliable amp.
Sounds like a failing capacitor in the power supply. When they are damaged, they will not charge properly. Eventually (about 30 minutes?) they will hold a charge and function at a percentage of their actual capacity. Look for bulging or leaking capacitors as well. This is a common problem in TV power supplies.
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Dear Tubedude:
Impressive response of good news. I'll get out the screwdriver and a lupe and see what's in there.
I'll let you know how it turns out. Thanks.
Randy H
(Re. tubes: The first time I heard an Audio Research tube amp--circa 1980--I knew there was something different going on, but couldn't place it. Then later I realized: I could for the first time understand the words a large chorus was singing! I got that used-but-good AR. Now it is largely inactivate except for special moments; usually the good old Yamaha gets the job. And thanks to you, hopefully, it will have an easy fix and live long and prosper. Same best wishes to you.)
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