Audio Research SP3-a1

Purely for informational purposes, from that legacy database of ARC stuff: http://www.arcdb.ws/SP3/SP3.html 

Love the black and gold faceplate now. It's totally pimp. I thought it garish when I bought mine new, and went for silver. 
PS: schematic for SP 3-a-1 in the link if you scroll down.

I remember retubing mine in the early '80s- a raft of Telefunken 12AX7s. Cost a total of around $80 for the entire complement. 

Update on SP3-A1, I decided to let ARC do the repair, It was up there (at least I won"t lose  the shipping) . The pre amp will have a warranty and full documentation . What the Heck ." Life is to short "!

Good to get the monkey off your back!

Got another bag of Monkey's, I have  an old D-150 ARC amp., that needs some attention also !

 I sent my V70 amp to Audio Research some years ago. The amp was almost 20 years old at the time. They did a superb job on it and the inside looked like new. I think they actually cleaned the circuit board. I would not be surprised if they do the same type of thing to your preamp. They want to clean every thing thoroughly and check every connection so it sounds it's best. Let us know what happens when you get it back.