Yamaha CS-30 Service Manual page 35

CS-30(S/it 1001—)
E. Hold Circuit
When HOLD button is continuously depressed with the same setting as the above paragraph (a), the
voltage levels of +2 ± 0.05V with the timing of PITCH 1 and +4 ± 0.3V with the timing of PITCH 2
to n should appear respectively.
3. Envelope Generator Circuit
A. EG1
a. Respectively turn KBD/SEQ/EXT selector switch (PSW4) to KBD, NORMAL/TIME x 5 switch
(PSW7) to NORMAL, INITIAL LEVEL lever (PVR10) to -5, ATTACK LEVEL lever (PVRII)to +5
and DECAY TIME (PVR13) and RELEASE TIME (PVR14) levers to S positions.
Turn the ATTACK TIME Lever (PVR12) until
+8
± 0.1V is obtained at TP3. Adjust VR
6
) so that
the rising curve as shown in Fig. 1 with T of 4 ± 0.1 mS is obtained from terminal A ( 3 —1) when the
key is ON (—7V is applied to the terminal TR ( i —5). In addition, adjust [VR 5j so that the voltage
is levelled off at 0 ± 0.1 V 5 seconds or later after the key has been turned ON.
b. Turn the ATTACK TIME lever until +3V ± 0.1V is obtained at TP3 and turn the key ON. Adjust
[ VR 7l to lengthen T when it is longer than 125mS or to shorten T when it is shorter. Raise the TP3
voltage level to
+8
± 0.1V and adjust [VR
8
) again to 4 ± O.lmS. Repeat this adjustment until T
becomes 125 ± 5mS when +3 ± 0.1 V is applied to TP3.
c. The inverse waveform of terminal A output should be obtained at terminal B (
3
-
3
). Confirm that
the above T is multiplied by 3.3 to 6.1 when NORMAL/TIME x 5 switch (PSW7) is in TIME x 5
position.
Also make sure that LED indicator (LE9) glows when the key is ON.
B. EG2
a. Respectively turn KBD/SEQ/EXT selector switch (PSW5) KBD, NORMAL/TIME x 5 switch (PSW
8
)
to NORMAL, both DECAY TIME (PVR16) and RELEASE TIME (PVR18) levers to S and SUSTAIN
LEVEL lever (PVR17) to 0 positions.
Turn ATTACK TIME lever (PVR15) until
+8
± 0.2V appears at TP4. Adjust (VR 9 so that the
rising curve as shown in Fig. 2 is obtained from terminal C ( 3 —7) with T of 4 ± O.lmS when the key
is ON (—7V is applied to terminal TR (
1
-5). Also adjust VR
8
so that the voltage is levelled off at
0 ± 0.01V 5 seconds or later after the key is ON.
b. Turn the ATTACK TIME lever until +3 ± 0.1V appears at TP4 and turn the key ON. Adjust
fvRIQ
to lengthen T when it exceeds 125mS or to shorten T when it is less than that. Raise the voltage level
of TP4 to
+8
± 0.1V and adjust j VR
9
] again for 4 ± O.lmS.
Repeat this adjustment until T becomes 125 ± 5mS when
TP4 is +3 ± 0.1V.
0 ±0.01V
Pig.
2
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