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Hello Polysix communty
Im in france, sorry for my poor english
I have a polysix with strange trouble.
All the polysix work now except it is impossible to tune it correctly.
The polysix is too low, 3 1/2 tones to low.
It is not possible to correct this trouble with Trims (VR1,VR2,VR3,VR14,VR15).
I change IC17,IC31,IC39,IC18,IC30,IC19, all capacitors in the master tune area,
check all resistors in master tune area. I change too Q12, and I check to
replace PC1 with Vtl5C9. The trouble keep in place....
It is difficult to understand the master tune in the shematic, very complex and
the quality of shematic in this place is confused.
All DC voltages are OK, the pitch bend sems OK , alls controls are OK and the
sound is good, just too low.
If I do a measure with oscilloscope on pin 7 of IC18 I read a rail to rail (sort
of square signal bewteen -15V to +15V). I know this is not normal, I should be
read a dc voltage, not a sort of square voltage.
Can you help me, have you an idea ?
I can do some measure at differents tests points If you wants to know more.
Thanks a lot and sorry for my poor english.
Best regards
Franc