Looking for good repair shop in Chicago

Check out Deltronics - they have two locations: one in Chicago the other in Woodridge. I had them do a little work on a Sonic Frontiers Line 1 preamp a couple of years ago and they did a good job for a reasonable price.

http://www.deltronicschicago.com/

A dealer friend from the Northside sends most of his stuff to Deltronics, he says they do good work. I have never had anything repaired at Stereo Exchange but I drop in occasionally and they always have some great vintage gear. Nice guys too.

I second using Stereo Exchange in Lincoln Square. I would've used Deltronics but their hours were too inconvenient for me. Dave fixed my Unico SE that was badly damaged in shipping after I bought it through Agon.
When I brought it in he handed me a screwdriver and told me to pop the lid while he kept working on some big child's toy made out of green plastic. Then he inspected the amp with me to point out everything that would need fixing - must've dropped it off of a loading dock! Great guy who put in lots of hours fixing it. Also, he insists on keeping amps for a couple of extra days to stress test the repairs.

Try Musician Custom Electronics in Chicago Heights off Halsted St. Ask for James, he is very honest and knowledgeable.

I recently had Dave at Stereo Exchange repair a vintage HK tube receiver and a newer, high end tube amp. Both now work well and, equally important, both were returned in the same (mint) cosmetic condition in which they were dropped off.