Hi,
I have uploaded a redrawn schem of the Poly6 antilog circuit. I hope this will help
anyone who is working in this area. If we learn more about how to adjust
the trimmers, I will add it to the schematic. The 17.5 mV/oct value was lifted from
a clear copy of the older key assigner schem. It finally hit me that IC30 is for detuning the voices in Unison mode. Duh! Not sure why I didn't think of that before.
Bob
I have uploaded a redrawn schem of the Poly6 antilog circuit. I hope this will help
anyone who is working in this area. If we learn more about how to adjust
the trimmers, I will add it to the schematic. The 17.5 mV/oct value was lifted from
a clear copy of the older key assigner schem. It finally hit me that IC30 is for detuning the voices in Unison mode. Duh! Not sure why I didn't think of that before.
Bob
From: Malte Rogacki <gacki@gacki.sax.de>
To: PolySix@yahoogroups.com
Sent: Sunday, March 2, 2014 9:05 AM
Subject: Re: [PolySix] RE: Polysix tuning difficulties.
To: PolySix@yahoogroups.com
Sent: Sunday, March 2, 2014 9:05 AM
Subject: Re: [PolySix] RE: Polysix tuning difficulties.
And finally:
I've tuned the Polysix (so far just preliminary). There still is some small
room for improvement but except for the lowest 16' octave I have a pitch
deviation better than the one shown in the service manual. Some notes have
a 1 to 2 cent deviation but most are spot on. The lowest notes in the
lowest octave have currently a deviation of about 7 cent.
I had to use VR15 a lot though which means that probably the basic offset
was not so good. The whole antilog circuit calibration could probably be
shifted a bit upwards and then compensated for again with VR15. This could
possibly bring VR2 away from its end position.
I've tuned the Polysix (so far just preliminary). There still is some small
room for improvement but except for the lowest 16' octave I have a pitch
deviation better than the one shown in the service manual. Some notes have
a 1 to 2 cent deviation but most are spot on. The lowest notes in the
lowest octave have currently a deviation of about 7 cent.
I had to use VR15 a lot though which means that probably the basic offset
was not so good. The whole antilog circuit calibration could probably be
shifted a bit upwards and then compensated for again with VR15. This could
possibly bring VR2 away from its end position.