Audio Research SP-3A-1 part

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!

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.

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?

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

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 ;>')

Tell her to think of it as "repair and maintenance", cheaper than buying something new. If your otherwise good car needed a transmission rebuild for $2k, compared to a new car for >$20k, she would say "fix it", wouldn't she?

Thank you. I sent the email per HiFigeek1's suggestion. On the regulator board upgrade - do any of you have any experiance with the Curcio board? It seems to do the job and eliminate the twist lock caps. They also have suggestions on better riaa equalization and cap. upgrades. Just wondered as I'm seriously considering going that way. The cost of the SP-3C upgrade puts it in the price category of "honey, can I spend MORE on MY hobby", and she will take a dim view I'm sure..... Now if it were HER hobby..... Ah...the married life!

Hi there....Send an email to service@audioresearch.com. The parts guy is Kal. They do have the bulbs. I would order a few at a time. You may also wish to consider their tube dampers which work great, and are reusable. I own an ARC SP-3C and as Mabonn says, the update to SP-3C is an excellent idea and transforms that preamp! The old twist lock power supply caps are miserable as are the zener string voltage regulators. Before his passing, Bill Johnson designed a new FET regulated power supply for that preamp. It's truly wonderful.

Hifigeek1 is an ARC tech. Maybe he has this lamp? Send him a message through Audiogon and ask.

ARC may be your best bet. Maybe you would get a better response from them if you said you were interested in sending it back to the factory for upgrade to SP3c.