When you feed it a signal, does it still light up the VU meters on the front? They’re fed from the tail end of the power amplification stage but just before the protection circuits — so if the meters still work, the amplification circuitry is still good and there’s a problem in the protection / relay section.

If the meters do work, are both A and B outputs broken? If yes, it’s almost certainly one of the protection circuits. If B works but not A, it’s almost certainly the A-channel relays (and you can maybe live with using the B outputs instead).

Have you opened your equipment and drawn out the circuit? Going in, I had no idea whether these amplifiers used voltage or current for remote standby, and how much. You’re going to want to know that for sure before you start sending electricity into whatever it is that you have. And the circuit that you discover will tell you what you want to feed in.

I’m looking at doing a similar application but am not sure how to do it.
Do I put 5VDc through the input and return it through the output back to the source or do you just feed the 5VDC throught the input and use the components shield as the ground referance with no return line throught the output.

Basically to I make a complete loop or just a single wire input?
what do you recommend limiting the current to?

Thanks for the help.
- Brent

The real issue, though, is that the fuse probably blew for a reason. If you’re lucky, the reason is that you were playing your music too loud at the same time you bumped the amplifier and the hot filament in the fuse just gave out . . . but my experience with SAE’s engineering doesn’t lead me to suspect it would fail under normal operation, no matter how hard you’re pushing it. No, I suspect you have a component failure that shorted something internally, and the fuse did its job, but you still have a broken amp.

My best suggestion is to find a repair shop in your area with a technician who knows transistor amps inside and out, rather than a new tech school graduate who only knows how to work off the manufacturer’s troubleshooting chart (since there aren’t any for these old amps). And that’s not a happy thing to have to tell you.

The other option is, yeah, find yourself another A501 (or other model) somewhere. And if you do that, don’t throw out the broken one — even broken SAE equipment can bring a fine price on eBay, so at least sell it to someone who can (try to) repair it.

Sorry to be the bearer of bad news, and best of luck with it!

I just saw a couple on eBay and remembered which model they are. Hang onto that baby! That’s a nice amp.

For price, I think you’re best off watching eBay for a while or using one of the services that shows you recent auction-end prices. I know a few A501s have sold in the last few months; but not being in the market for them, I haven’t paid attention to price. I would guess they bring $75-200 plus about $40 to ship.

If you’re using the A501, and don’t have other gear that you want to replace it with, I’d say keep it. I’m personally enamored of the A502, but all the SAE stuff is really pretty good gear.