Service manual

DETAIL A
IC 4 OUTPUT
KEYBOARD CONTROL
VOLTAGE
~+7V
+4.5V
OV
-4.5V
I—1ST KEY
DOWN
t2ND KEY DOWN 1ST KEY-]
JD KEY UP—I up
DETAIL B
IC 5 OUTPUT
DC KEYBOARD
DETECTOR
+7V
OV
-16V
DETAIL C
05 COLLECTOR
TRIGGER PULSE
+9V
OV
-7V
-12V
■20 MSEC
DETAIL D
08 COLLECTOR
DC TRIGGER
+9V
OV
20 MSEC
DETAIL E
Q4 BASE
KEYBOARD SAMPLE
AND HOLD DRIVE
+8V
DETAIL F
SOURCE OF Q51
SAMPLED KEYBOARD
CONTROL VOLTAGE
+4.5V
OV
-4.5V
PREVIOUS
NOTE
DETAIL G
OUTPUT OF IC 6
AC KEY DOWN
DETECTOR
+8V
+ 1.5V
OV
-1.5V
-8V
-I I*— 1.5 MSEC
1.5V MIN
(FOR ADJACENT
SEMITONES)
\r
FIG URE 2-1 KE YBOA RD TRIGGER VOL TA GE WA VEFORMS
17