Yamaha CS-30 Service Manual page 31

CS-30(S/# 1001 ~)
c. Leave adjustments as in 2—(b) and use the CUT OFF FREQ (PVR8) to adjust for a TP3 voltage of +7
± 0.1V. Then turn the Bs key ON; when the KBD FOLLOW (PVR4) is set for 500mV at the second
pin of IC
2
the LP2 level should just peak.
Next, when TP3 voltage is+3 ± 0.1V turn the B
2
key ON. When the KBD FOLLOW (PVR4) is used to
set for 500mV at the second pin of IC
2
the LP2 level should peak.
d. Return the setting to the 2—(a, b) condition. When the MOD FUNCTION (PSW5) is set to
f\J
and
MOD DEPTH (PVR10) to 10 check the cutoff frequency by listening to the sound according to the
input
f\J
wave.
e. Set EG1 ~ 3 to any position and EG DEPTH (PVR12) to approximately center position. Peak fre¬
quency should vary according to the EG waveform when the EG SELECTOR (PSW12) is switched
from A to E.
3. KBD FOLLOW Circuit
a. When the F
2
key is ON (with 166.8mV present at the KV ((T)—7) terminal), adjust [ VR
7
) so that
OmV is present at TP1.
b. With the KBD FOLLOW (PVR3) set to 0, adjust (vr
5
) so that the FI I ((T)-
6
) terminal receives
166.8mV.
Then set the KBD FOLLOW (PVR3) to 1 and turn the C6 key ON. Check for 2.000V at the FI I
((T) —6) terminal.
c. As in 3—(a), with the KBD FOLLOW (PVR4) to 0, adjust (VR 6) so that 166.8mV appears at the
F2I (([,—4) terminal.
Next, set the KBD FOLLOW (PVR4) to 1. Check for 2.000V at the F2I (®-4) terminal when the
C6 key is ON.
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