Hey fellow Michiganders! (and northern Ohioans) Can any of you recommend someone who does tube amp diagnostics and repair, in Southeast Michigan/Northern Ohio? I live in Ann Arbor, and am having a tough time finding someone who does this sort of work. The only music repair shop in my town is the venerable Herb David Guitar Studio. They have a legendary repair shop, but their turnaround time is pretty slow. I need to find someone who is not only competent, but speedy, to fix my ailing Mesa Boogie Buster bass head.