QuestionI have fairly old Adcom components - a GFA-535 amp and a GTP-500 tuner/preamp. I'm using a Rotel RCD-955 AX cd player that I bought second hand. The problem is that when I'm playing music one channel (usually the left) will drop out. Oddly, this problem can sometimes but not always be solved by turning off the power button on the amp for a few seconds and then turning it on again. Sometimes I can get a fix by jiggling or turning the cables that connect the CD player into the preamp. But the problem seems to be getting worse and I'm wondering if I should be thinking about retiring this equipment. If there is a relatively simple and efficient way to fix this problem I would prefer that to laying out money for new components at this point. Thanks.
AnswerDear Jonathan,
"Fairly old"? I've had both the GFA-535 and GTP-500 running a small system in our living room for years, and they're still humming along. I'm not sure, pound for pound, that there are better value pure audio components out there. And, yes, I still have my revered 955AX, now running in my studio above the garage, which has been going nigh on 11-12 years without a glitch--well, none at least since I got the drawer to stop opening and closing at will! This is to say: you have excellent gear and should not give any of it up until one or the other quite literally falls apart.
(BTW, the 955AX is mated with a ca. 1976 Sansui AU-417 integrated amplifier, which simply refuses to quit on me.)
The quick fixes you describe would ordinarily point to very different symptoms. First, turning the power amp off and on might indicate overheating in the output signal. Second, jiggling the cables would indicate that the terminal connections inside the preamp are loose. Could be both.
What I would do is remove the cover to the GTP-500 (after it's unplugged of course...ahem) and tighten the set screws that hold the CD input terminals to the chassis. Without putting the cover back on, reconnect everything and fire it up and see what happens. If you simply have a loose input terminal, then your job's done. However, if the channel poops out again, then you need to disconnect it and look for loose wiring. If you find any, solder it back into place.
The two troubles with older gear are (1) they get dusty and (2) things come loose. Both are simply a function of age. I recommend taking a very low powered electronics vac to the interior of both the amp and preamp every couple of years or so.
If you've gone through all of that, and the channel still fails, then it's time to look elsewhere. However, I'd still stick with the preamp. Turn *it* (not the power amplifier) off and then on. What happens? Was the channel restored? If nothing happens, *then* turn the power amp off and on. If the channel is restored, then the problem is with the power amplifier.
I don't recommend that amateurs try fixing power amplifiers. They're complex pieces of engineering, and by "fixing" one thing, you can very well cause another to fail. (Preamps are just switch boxes, so it's pretty hard to screw 'em up, so long as you're careful.) I'd take the amp to a hi-fi repair shop and pay 'em the nominal 1/2 hour labor charge to run a bench test.
I think that $100-200 to fix your current equipment is a far better investment than junking them and buying new stuff. You're simply not going to find as excellent performance for the same money. You have excellent components. Don't give up on them without a fight.
Good luck! And thanks for choosing allexperts.com!
Kindest regards,
Kevin
