Audio Research SP-3A-1 part

Consider cryo-treating wifey. I posted the same suggestion on another OP that asks for thoughts on cryo-treating gear. Tremendous improvement in lowering ambient noise when listening to the rig. LOL ;>')

If you get an after market power supply for that preamp you will destroy it's resale value should you decide to sell it....

Ha! OK, replaced the lamp. No instructions came with them, but it became clear the front would need to come off to access the lamp itself. I was then able to unscrew the assembly and removed a most peculiar looking lamp. It had the green lens firmly attached to a metal stub, and inside was the lamp itself. I didn't realize that the lamp could be backed out, as it had been in there so long that it had more or less, self welded itself into one piece. So, I used a 15 watt soldering iron to briefly heat the metal tube so i could work the green bezel off - that brief application of heat caused the green bezel to distort on the edges, but it did come off. NOTE TO ALL OTHERS - DON'T DO THIS! It was a pain to file down the shriveled edges and refit the assembly with the new bulb back into its tight socket. Instead, just back off the bulb from behind. You may need to use a hobby knife to excavate the flange mating, but this would be SO much better than what I did. Anyway, back in, and it lights and looks as it should, BUT -

I lost a channel right after this! The left channel just went dead; no smoke, no noise, nothing. I used my trustworthy Hickok 600 tube tester, and all tubes were fine. No broken wires, no obvious broken or burnt components. All pots, and wiring appear good and solid. I traced the RCA jacks back to the board, and that all is good, at least from what I saw.

So - any thoughts on this one? I sent an email into ARC service, but Kal is on vacation. Could this be a PS board issue? If so, guess no such factory type caps availabel anywhere.....?

hey - Hifigeek1.....want to look at this baby?

I doubt the power supply is at fault as one channel is operating. Try actuating all the push button in the center of the unit, one at a time. You may have some dirty switch contacts, or the selector switches for the same reason. I would be happy to service the unit for you.

Epilogue(and why almost blind people shouldn't work on their stuff) - I just came back from the local audio shop. After 5 minutes I was leaving with my perfect SP-3A-1. When I reassembled the front face, I apparently pinched off a wire from one of the pots. While he was working on some Pioneer receiver, I removed the cover to save him time. He peered in, poked his finger around, grabbed his soldering iron, and fixed it. Then went back to the Pioneer.It sounds great, both channels. He did say that it was the nicest looking SP-3A-1 he's ever seen. Well, that was nice to hear anyway. So, be careful everyone - those front wires can get trapped between the front of the chassis, and a pot. as you tighten the front retaining nut! oops! 60 years old, diabetes and soldering irons - Don't do it!