Thanks Kev, that's very helpful. I would not have guessed the 9500 is that much more difficult.
By the way, have you ever compared the TU-7900 to a TU-9900? Is there a big difference in the sound or sensitivity or is it more of an incremental difference?
Well, the TU9500 I restored/Aligned for a customer turned out really good, but because of the ver discrete nature of the circuits, its very time consuming to align, and you often have to go back and tweak it for a final touch up, there are cap upgrades, and a lot of noisy old transistors to replace in them, then because they have no 50µS option for New Zealand, I had to modify the de-emphasis circuit......Just a lot of fiddling around required.
Never had a 7900 and 9900 side by side, obviously the 9900 is quite impressive, but I would say the 7900 is no slouch, and definitely going to be more reliable and consistent in its performance than a TU9500.
I have just finished a alignment/modification on a TU999, I just did a swap with a friend for the most mint AU999 and TU999, I restored the amp last year, its the most mint 999 I have ever seen, with the wooden case, and now its mine with the matching tuner.
The TU999 is in the same boat as the 9500, but I think the 999 is a much better sounding tuner, better design. When I first had it on the bench it was showing about 0.4% THD, when I was finished with it, I got it down to 0.025% THD, and it sounds great, I might do something with the final LPF as I think its stealing a bit of top end, but its a very beautiful sounding tuner....
