Korg POLY-61 - VCF Resonance and Cutoff Checks

DETUNE 1 ± Ocent (adjust with TUNE knob.)
2 +4 cent (± 2 cent)
3 +8 cent (± 3 cent)
4 +18 cent (± 5 cent)
5 +40 cent (±10 cent)
6 +60 cent (±15 cent)
(3) Return PW/PWM CV terminal to original condition.
4. VCF check and adjustment.
1) RESONANCE.
(1) Set to PROGRAM 32 and observe SIGNAL OUT
IC6 1-pin (IC3 1-pin) on oscilloscope.
(2) Play C3 and confirm Fig-6 waveform for 6 voices.
Adjust VR104-604 (VR102~602) (RES ADJ)
if necessary. In this case, be careful that waveform
does not become as shown in Fig-7 or Fig-8 .
(3) S et PROGRAM to 33 and confirm Fig-9 wave¬
form.
(4) Change PROGRAM to 34, 35, 36, and 37; confirm
gradual increase in ringing, reaching instability at
37.
RR
SR
1^1
ISSIU
2) CUTOFF FREQUENCY check and adjustment.
(1) Set to PROGRAM 38; play Cl and confirm Fig-10
waveform.
1
_
/div, 5m;
m
Fig-10