Sony MX-P21 - Page 13

SECTION 3
MX-P 21
MX-P 21
ADJUSTMENTS
+5 V VOLTAGE ADJUSTMENT
When components in the DC-DC converter are re-
placed, perform the following adjustment.
Set Up:
DC-DC converter is properly connected to the rest,
ie., properly loaded. Use adequate line (mains)
voltage.
Procedure:
Adjust R18 so that the test-point (output line of
+5 V) voltage becomes in +5.00 V.
Adjustment Location:
— DC-DC converter board —
test point
LEVEL METER ADJUSTMENT
Set Up:
PAN control: _C (center click)
EQ switch: OFF
LCF switch: OFF
MIC LEVEL control: —60
LINE/MIC/PHONO switch: MIC
Procedure:
af osc
€) attenuator
O
MIC INPUT 1
1 kHz, —60 dB (0.77 mV)
LINE OUT (balanced):
+3.6 dB m (1.16 V)
AUX OUT: —5.4 aB (0.42 V)
. Adjust MASTER control so that balanced LINE
OUT level becomes in 3.6 dBm (1.16 V).
. Adjust RV302 (L-CH) and RV304 (R-CH) so that
MASTER level meter reads ‘‘0”’ indication.
LINE OUT MAXIMUM GAIN ADJUSTMENT
Procedure:
AUX 1 MAXIMUM GAIN ADJUSTMENT
Set Up: Set Up:
PAN control: C (center click)
EQ switch: OFF
LCF switch: OFF
MIC LEVEL control: —60
LINE/MIC/PHONO switch: MIC
PRE/(post) switch: post (not depressed)
PAN control: C (center click)
EQ switch: OFF
LCF switch: OFF
MIC LEVEL control: —60
LINE/MIC/PHONO switch: MIC
Procedure:
af
osc
af
osc
ae, attenuator
O
VTVM
© attenuator 6002 6002 7]
O
Oo——O Oo ©
scood = Rt
MIC INPUT 1 LINE OUT (balanced)
MIC INPUT 1 AUX 1 (OUTPUT)
1kHz,—-70dB(0.25mV) +14dB8 (3.9 V)
1 kHz, —70dB (0.25 mV) +15 dB (4.4 V)
Adjust RV301 (L-CH) and RV303 (R-CH) so that
the gain from MIC INPUT 1 to balanced LINE
OUT becomes in 84 dB.
Adjust RV305 so that the gain from MIC INPUT
1 to AUX 1 output becomes in 85 dB.
. Adjust AUX OUT 1 and AUX OUT 2 controls so
that AUX OUT 1 and AUX OUT 2 output levels
become in —5.4 dB (0.42 V).
. Adjust RV306 (AUX 1) and RV308 (AUX 2) so
that AUX level meters indicate ‘‘0”’.
Adjustment Location:
— PGA board —
Adjustment Location
— PGA board —
Adjustment Location:
— PGA board —
ay
Bik:
RV304 RV306 RV308
(R-CH) (AUX 1) (AUX 2)