JS Audio previously upgraded my MF A300 amp that still sounds fantastic so had John do a Stage 2 upgrade on my CD Player including new valves. Initially It sounded better and had greater detail but 4 months on and time to run in the improvement is another level. The separation of instruments, soundstage, detail is just superb, it constantly brings a big smile. Both of the items JS Audio have upgraded are now 20+ years old and would highly recommend them.