I've got one of those Hitachi HMA-7500's and I can tell you it sound truly brilliant for such an old amp. I was going to gut it as I really like the look, but after playing with it a bit I decided to just leave it the way it is.
Sheesh Gert, reason has prevailed
and those are gen-you-ine tested and replaced mosfets in there... Eventually found them in Cape Town (by chance) from a guy that fixes radars for a living...
