Sansui BA-3000 - Adjustments; Driver Circuit Board Adjustments; Power Meter Adjustment

3. ADJUSTMENTS
3-1. Driver Circuit Board Adjustments (Fig. 1, 2, 3, 4).
Note: 1. Master Volume.............-.+-+5- Minimum
2. Room Temperature ................ 10~35°C
3. For adjustment, run the unit for more than 5 minutes after ther power is switched on.
SUBJECT EQUIPMENT MEASURE OUTPUT | ADJUST ADJUST FOR CONDITION
DC OV DC Volt Speaker Terminal F-2507 OV VRO2....Minimum
Meter Fig. 4 VRO1 +10mV (Counterclockwise)
: (Fig. 3) 2)
Blas Current DC Volt F-2510 F-2507 20mV _ Vv
Meter 2-4 (Connector Pin) | VRO2 % 1) mor = POR
(Fig.
2)
(Fig.
3)
i
20
: v = p04 =20mA
% 1) Instead of measuring bias current, set the voltage to 20mV by VRO2 between connector-pins Bip an we
2 and 4 on both channels as Fig. 2, since there are no quick acting fuses in the power TRo3p4 a ee
amplifier sections.
3% 2) On one channel, bias current, |, is current which flows into one power transistor, 25C1585.
Nemaly, total current on one channel=1, x3
L-CH.......00. TRO1, TROS, TROO
R-CH_ ........ TRO2, TRO6, TR10 Fig. 3 Back Panel ;
Fig. 2 Back Panel = 1
uch'—rcu
VRO1 7 VRO1
Bottom Side :
Fig. 4 ‘Speaker Terminal
F-2512 Connector Pin RIGHT LEFT
= + + =
R-CH L-CH VRo2 || VRo2
oO
a a VoltmeterQ
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o oO a ®D
= < 2 3 Volt meter© Volt meter®
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Front Panel Front Panel Tope Side
3-2. Power Meter Adjustment (Fig. 5, 6, 7) RCH LcH
Note: 1. Room Temperature ........ 18~28°C VROu fenee ye ares
2. Level Volume .............. Maximum F-2515 S) ©) F-2515
3. Input Signal ................ Sine Curve (1kHz) | fewer meter | | | i
4. Speaker load ..............0. 0000 c eee 80
5. For adjustment, run the unit for more than 5 Front Panel
minutes after the power is switched on. is Fig. 7
STEP SUBJECT OUTPUT LEVEL ADJUST METER POSITION
1. Power Meter 36.9V F-2515 Togs _ et ug
Adjustment (OdB) VRO2 (Fig. 5)
Fig. 7)
2. Power Meter 369mV F-2515 —40dB [aw a
Adjustment (—40dB) R (Fig. 6)
3. Confirm the Step 1 again. If the meter position is not within OdB +1dB, repeat
‘from step 1, 2.
% On both channels, above adjustments are necessary.