Adjustment - Pioneer S-FCRW230 Service Manual

7. ADJUSTMENT

ATTENTION
¶ Don' t make speaker terminal short circuit during the power supply injection.
¶ Since the PRIMARY part of the AMP ASSY is not insulated, be careful of electric shock.
¶ Be sure to disconnect the power supply cord before touching the AMP ASSY board.
¶ Discharge the C13, C14 capacitors!
7.1 MEASURING INSTRUMENTS
¶ Provide yourself with the following measuring devices:
(1) Digital voltmeter
(2) Oscilloscope
(3) Attenuator
(4) Low-frequency oscillator
7 7 7 7 7 GAIN Adjustment
(1) Decrease the level of the Adjustment Variable resistors (VR) for the channel to adjusted.
(2) Increase LEVEL VOLUME maximum.
(3) Adjust GAIN (VR41) volume.
¶ Apply the signal to the Line IN of JA201.
¶ As the gain from IN to SPEAKER OUT 53dB(freq. = 50 Hz), input of 10mVrms to Input results in output of 0.72 W (4.5
Vrms/28 W) at SPEAKER OUT.
¶ After power-supply ON, after waiting abut 10 seconds, it adjustment because, wave form rises behind time for slow
start operation.
Test Point
Digital
Voltmeter
-
Adjustment VR
+
28Ω
3 W
VR41
Gain Adj
A
AMP ASSY
S-FCRW230
SIDE A
15