Yamaha CS80

Hey,

Have done some fresh calibration recently, have you checked the voltage of the K terminals on the
SH board (K1-8 near the CA3140T)  ? should be 125mV on CS-60 & 80 (250mV on CS-50). if these are to low it would seem
as the voltage is "divided" in a weird way resulting in very strange tuning (almost as if the whole keyboard
got an "extra" octave to divide by).

The CS i worked on had several problems with the mylar,ceramic and polystyrene caps, touching them
would result in noises and tuning drift. I replaced them all and now the CS is rock solid. I also replaced
the mylars in the SH circuit.


-----Originalmeddelande-----
Från: musicalfix@...
Till: yamahacs80@yahoogroups.com
Datum: 2013-10-03 18:34
Ämne: [yamahacs80] CS80 tuning

      
Hi all, I have a question regarding the CS80 tuning. I have followed the service manual instructions, i.e set upper octave pitch, then scale with the lower octave using V3 and V2 and then repeat until both are within 1 cent. This works fine for some voices, but for others, having done that I then find the middle C is around 6/7 cents out.  If I tune middle C then the lower octaves are around -15 cents. Should I be able to get it all to within 1 cent as it says? I could spend the rest of my life doing this!!