Yamaha CS-50 Servicing Manual page 61

[OUTLINE OF OPERATION]
o Ring Modulator
330
!OK
INPUUT
lO~l~
From buffer amplifier
,.-!'1-'-'\llv\r--.-------+----1
lOOK
+15V
390
2. 7K
1.2K 2. 7K
From ring modulation
oscillator
OUTPUT
To buffer
amplifier
By the low frequency modulation signal from the ring modulation oscillator, ring modulation is conducted. The
sound signal from the M circuit board passes through the buffer amplifier and is input into the No. 1 pin of the IC
for ring modulation. The signal accepts the ring modulation by the low frequency m"odulation signal to be added to
the No. 7 pin, and is output in the No. 6 pin. Theoretically, when one of the two signals is not input, the output of
RMO terminal becomes zero. However, the modulation signal is characterized by leakage output according to IC
abberation. The VRS adjusts and controls the leakage signal to less than 3m Vp-p.
Sound signal input(+)
Gain control
Gain control
Sound signal input(-)
Bias
IC
p
A796HC
Modulation signal
input(-)
Modulation signal
input(+)
NOTE: Terminal layout of IC
(J.LA
796HC)
in can-type package.
62---------------------------------------------------------------------------