41
M-AX10
6. ADJUSTMENT
6.1 IDLE CURRENT ADJUSTMENT
The idle current is adjusted in two steps: coarse and fine. Note that
the adjustment value for fine adjustment depends on the elapsed
time from the coarse adjustment.
For the points to be adjusted or measured, see Table 6-1 and Fig. 6-
1.
For the adjustment timing and values, see Table 6-2.
Be sure to turn VR501, VR502, VR601 and VR602 fully counter-
clockwise before turning the power on.
6.2 DC OFFSET ADJUSTMENT
Adjust the DC offset with the power on immediately before fine
adjustment of the idle current.
For the points to be adjusted or measured, and the adjustment values,
see Table 6-3 and Fig. 6-1.
6.3 OPERATION CHECK OF THE
PROTECTION CIRCUIT
While supplying a sine wave of 1 Hz, 1.2 Vrms in DUAL MODE,
with ATT.THROUGH OFF, increase the volume level and check
that the protection circuit activates before the level reaches the
maximum value. It works about before twelve o'clock position.
CAUTION : This check mode may damage the speaker(s) when it
is connected to the output terminal. It is recommended
that output terminal is open at this check mode.
Channel
L High ch L Low ch R High ch R Low ch
Adjustment
point
VR501
VR502
VR601
VR602
Measurement
point
CN505
CN505
CN605
CN605
Between
pins 1 and 2
Between
pins 3 and 4
Between
pins 1 and 2
Between
pins 3 and 4
Table 6-1 Adjustment points of idle current
Table 6-2 Adjustment values of idle current
Adjustment Timing
Adjustment value
(Pin voltage)
Coarse
Adjustment
Power ON immediately
14.5mV
±
1.0mV
Fine
Adjustment
Elapsed
time from
the coarse
adjustment
More than 5 min.
and less than
10 min.
16.0mV
±
0.5mV
More than 10 min.
and less than
15 min.
15.5mV
±
0.5mV
More than 15 min.
and less than
30 min.
15.0mV
±
0.5mV
More than 30 min.
14.5mV
±
0.5mV
Table 6-3 DC offset adjustment method
Channel
Adjustment
Point
Measurement Point
Adjustment
Value
L High ch
VR301
Apply channel speaker
terminals (Red, Black)
0V
±
10mV
L Low ch
VR302
R High ch
VR401
R Low ch
VR402
VR302
L Low ch
DC OFFSET ADJ
VR301
L High ch
DC OFFSET ADJ
VR502
L Low ch
Idle Current ADJ
VR501
L High ch
Idle Current ADJ
VR402
R Low ch
DC OFFSET ADJ
VR401
R High ch
DC OFFSET ADJ
VR602
R Low ch
Idle Current ADJ
VR601
R High ch
Idle Current ADJ
CN505
Fig. 6-1 Adjustment and measurement points
CN605
Rear Side
Front Side