A well-run audio / hi-fi service shop for equipment that is out-of-warranty. They have a staff of well-trained, competent technicians who know how to repair and perform routine maintenance on a wide variety of turntables, speakers, receivers, DJ mixers, solid state amplifiers, tube amplifiers, tapedecks, reel-to-reels and more, from the low-end to the high-end and everything in between, even if it's an audio piece or brand they've never seen before, which is always a sign of a top-notch technician. They will give you an estimate before performing any work. If it's worth having, it's worth maintaining.