Bias-Level Adjustment - JRC JSS-296 Service Manual

(b) Pull out the Power Amplifier unit from console.
(c) Remove the upper panel of Power Amplifier unit.
(d) Turn on the "AC" switch, pressing MENU .
(e) Press MENU and turn the dial to "80V ADJUST" menu on the LCD.
(f) Press ENT and adjust the PA(A) Vc to 78V by RV3.
80V ADJUST
PA(A) Vc 78.0V
(g) Press ENT and turn off the "AC" switch.
(h) Re-assemble the unit.
4.2.5

BIAS-level adjustment

Since BIAS-level is already adjusted at the time of factory shipments, it is not necessary to
Note
adjust it at the time of installation.
Procedure
(a) Turn off the "AC" and "DC" switches on the front panel.
C
CMC-2692/2695/2698
Dial
(b) Pull out the Power Amplifier unit form console
(c) Disconnect the all cables on the rear of Power Amplifier unit.
(d) Remove the under panel of Power Amplifier unit.
(e) Turn volumes* on the PA CONTROL UNIT (CMC-2692/2695/2698) fully counter-clockwise.
(*) CMC-2692:
CMC-2695:
CMC-2698:
(f) Connect the AC power cable only.
(g) Turn ON the "AC" switch, while pressing MENU .
(h) Press MENU and turn the dial to "PA BIAS ADJUST" menu on the LCD of Power Amplifier.
(i) Press ENT to display the PA BIAS-level.
(j) Gradually turn RV1 on the PA CONTROL UNIT clockwise until PA BIAS reading becomes 1.0A.
CAH-2692
PA UNIT
B A
PA CONTROL UNIT
AC switch
RV1, RV2
RV1, RV2, RV101, RV102
RV1, RV2, RV101, RV102, RV201, RV202
PA BIAS ADJUST
0.0 A
PA BIAS ADJUST
1.0 A
BIAS(A) 1
RV1
RV2
BIAS
(A) 2
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