S-FCRW220
S-FCRW720
15
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
VR41
Gain Adj
Digital
Voltmeter
AMP ASSY
+
-
A
SIDE A
28
Ω
3 W
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