Yamaha CS80

>I think the resolution of the one-turn trimmers is fine enough to
>adjust the oscillators for zero beating by ear (or let's say, 1 beat
>every 10 seconds, that's 0,1Hz isnt't it ?).

Well, my 2 Hz resolution at the higest C in 2' would equal something like 
you described in the middle region of 16' ...
Or did you really get 10 seconds of beat rate at 8372 Hz ??

>Very important is having oscillator-ic's all with the same temperature-
>code. One of my CS80's has all equal numbers and is immidiatly in tune,
>there's no difference in 1 minute warm-up or 2 hours warming up.
>My other CS80 has 2 ic's with different numbers, and there I've to wait
>for about 10 minutes (that used to be 1 hour before I renewed the
>thermical grease around the diode)...

I think 10 minutes is still a very good time.
My OB-8 takes as long if I don't auto-tune it (I avoid auto-tune).
Same for my CS-50.
My PS-3200 clone takes longer.

Ahh, and my new CS-80 isn't bad, either: I just tried the tuning from last 
night with the lid closed, and it seems to be ok after power-on, and after 
an hour of having it turned on. (Not _perfect_, but good enough for making 
music.)
Seems I've been lucky about the temp code matching. (Haven't checked the 
numbers yet - all boards are still inside the frame.)

JH.