Yamaha CS-30 Service Manual page 14

VCA
Circuit Board & Wiring
PSW7
PSW9
100/16
100/16
PVR3
A-50K
470K
10/16
100K
PVR5
B-10K
100/16
PVR2
A-50K
PVR |
A-50K >
PSW6
100K
(Note)
View from the printed pattern side of the circuit board
'<9
IC1 —4 : IG00151
IC5 : NJM4558
IC6 : HA1452
IC7 : /iA796HC
2. Transistor ( h =7 >\s7* 9)
Trl-5 : 2SC458
3. Phote coupler
PCI • 2 : P558-G50-201B
4. Semi Variable Resistor
UR1 -9 : V8K-4-1 Type
) 15 G
»
M
G
JIT G
)1 12 G
)l 11
G
)| 10
G
)| 9 G
3jl
G
■
) 4 02
» 3
G
| 2
■
! -L ♦ 10
KEP-NA 80291 -78 A
CS-30(S/# 1001
VCA-EG 1C (IG00159)
This 1C generates envelope wave shape which is
supplied to VCA and control the tone volume.
1. IL . Input o* initial level-
Fixed to 0V
2. Bl .
3 OUT ...
Input of buffer amplifier.
The buffer amplifier is built in for
the ihiipose of matching mpedance
Output wave shape.
DT
K AT
4. GND . Earth
5. Vcc . *15V input power source.
6. G1 . Gate 1
7. G2 .Gate 2
KEY ON /V KEY-OFF
0V 2»
■
1
_
AT starting data
Key ON OFF data
8 Vee .
♦ 15V input power source.
9 AT . Input of buffer voltage for determi¬
nation of attack time.
Input of the voltage between zero V
and 10V is provided and the attack
time is controlled from 1 mS until
IS k ATM
10. IDT . Input of buffer voltage for determi¬
nation of decay time.
Input of the voltage between zero V
and 10V is provided and the decay
time is controlled from 10 m second
until 10 second.
11 2DT . Input of buffer voltage for determi¬
nation of release time.
Input of the voltage between zero V
and 10V is provided and the time
key-off untill release is controlled
from 10 mS until 10 S.
12. TC . Output of time control.
Output of the DC voltage is pro¬
duced so that the each time of
Attack. 1st Decay and 2nd Decay are
controlled.
KEY-ON i OFF
Tune
control
voltage
The higher the voltage, the
shorter the time and the
lower the voltage, the lon¬
ger the time.
13. LC . Output of level control
Level
control
voltage
Output of the DC voltage
for AL and SL control is
provided.
The higher the voltage . the
higher the level and the
lower the voltage, the lower
the level.
14. NC.Not connected.
15. SL. Input of buffer voltage for determi¬
nation of the sustain level.
Input of the voltage between zero V
and 10V is provided so that the
sustain level can be controlled.
10
0
16. NC. Not connected.
-
12
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