I love pawn shops...Now a dilemma

Hi - First post here.

I was looking to golf my first 18 of the season, but the 2 courses in the town I was working in were closed. So my buddy and I swing into a pawn shop.

There I found a corroded Audio Research SP-5 for $59, in decent working condition following a short test. I even got a discount for some reason - $53 out the door.

Upon close inspection there is a red substance that has oozed out of most of the 1000mf 25v caps, and a bit of corrosion on the board itself. The volume pot was very noisy, but has cleaned up with use. The case and face are quite abused, the RCA connectors all are 40% rust, but I couldn't pass up the deal.

Now - after running for an hour or less, the right channel will erupt in static bursts, enough for me to worry about the tweeter so it is now on the bench waiting for me to do something about it. Luckily, AR is 10 miles up the road from me so I'll drop by the factory for, hopefully, a face-to-face with a tech. If I can buy the parts, I'm sure I can solder in the caps, and buy the RCA's from them or PE. Otherwise my budget can't take a large repair bill. I hope it all works out.

Anyone else have a similar experience with refurbing an older unit like this? Any advice on what to expect, or a better source than the factory for parts? ($$$, I know how markup works. However, they did mail me the cover screws for no charge, next day. Excellent CS so far).

- Frugal

Welcome aboard.

I think the static burst is coming from dirty volume potentiometer. Clean it (probably using contact cleaner) or replace it if possible. As for the corroded board you can clean it and apply tin solder on top of it. Make sure you don't use high wattage soldering iron otherwise you'll melt the board (I did, using 60 watt). Replacing leaking caps will likely improving the sound. Well at least I felt that imaging was improving on my refurbished Musical Fidelity Synthesis after I replaced many caps. The repairman just put any cheap caps as long as it works. The sound 'seems' to be improving further after I replaced the op amps with OPA series. Well good luck, hopefully you don't have to spend so much on your amp.

if you clean the volume pot with contact cleaner you have to relube it too. i would recommend Caig MCL (Moving Contact Lubricant) It does some amazing things, I use it everyday at work. Some parts from the factory will just be sent to you, others they will charge you for. You are better off buying the parts from the factory if you want it to be orginial (thats assuming they have them all). The only advice I can give you is check your output transistors, and touch up every single solder joint on the whole thing after you change whatever parts you change. One bad solder joint can lead to a lot of problems.

Thanks guys - I'll check back after I get some good information.

You lucky bum! I have never seen anything more than Best Buy or Wal Mart rejects at the pawn shop and you walk out with AR.

Even funnier is the fact that the pawn shop is in on a main drag through a tourist area in a very rural part of Minnesota. I expected Wal-Mart but got Tiffany.

They have a clean Kenwood M1 that would work great in my gym or garage for $90...maybe I'll go back for that...

You should've been there to see the guys puzzled look when I snapped the pre off of the shelf and whipped out my wallet. I thought he was going to jack up the price on the spot.

My house tech Fred will get his first look at it today. I found photos online showing big blue Mallory caps where my silver ones are now. Perhaps something will come of this yet...