Yamaha CS-30 Service Manual page 25

CS-30(S/Jt 1001—)
SSK Circuit Board
1. Power Supply for Key Assignor
+7V Adjustment.Make sure that voltage of +6.9 ± 0.6V is present at 1st Pin of ICi.
—7V Adjustment.Make sure that voltage of —6.9 ± 0.6V is present at 40th Pin of ICi.
2. Key Assignor Clock
Make sure that a waveform as in the figure below is obtainable at 2nd Pin of IC2.
--— -6.9± 1 V
-OV
-- -6.9± 1 V f = 9 ± 1 KHz
3. Pitch Bend Voltage Generator Circuit
a. Set the PITCH BEND knob to 0 position, then adjust (VR
4
] until 2.000V is obtained at CP6 or 2V
(@-6.7) terminal.
b. Set the LIMITTER lever to MAX position and PITCH BEND knob to "+" position, then adjust
(VR 6) so that 4.000V is obtained at PB (@—13) terminal.
Note: When PITCH BEND knob is in " position 1.00V is obtained at PB terminal.
4. Key Voltage Modulator Circuit
a. Set the PITCH BEND knob to 0 position, then adjust (VR
5
) so that —2.000V is obtained at CP7.
b. Adjust the TUNE knob until 0.000V is present at TU (@-10) terminal. Set the EG-DEPTH knob in
PITCH Section to 0 position, then adjust [VR
3
) so that 2.000V is obtained at CP8.
5. Key Voltage Generator Circuit
a. Press
F
2
key and adjust [VR 7] so that 250 ± 0.2mV is obtained at CP9.
b. After the item 4—(a) adjustment, adjust [VR l) so that 166.8 ± O.lmV is obtained at CP10 or PI
(@— 3) terminal.
c. After the item 4—(b) adjustment, adjust [vr
2
] until 166.8 ± O.lmV is present at CP11 or KV (@—1)
terminal.
6. Portamento Circuit
a. Set the PORTAMENTO lever to S position, press F
2
key, and then turn C6 key on, make sure that a
waveform as in the figure A is obtainable at KV (@-1) terminal.
b. Set the PORTAMENTO lever to L position, then make sure that a waveform as in the figure B is
obtainable at the same.
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