McIntosh MX120 User manual

MX120
SERVICE MANUAL
Performance Specifications ................................... 2 - 3
Notes ......................................................................... 3
Rear Panel .................................................................. 3
Section Location ........................................................ 4
Block Diagram ...................................................... 5 - 8
Interconnection Diagram .................................... 9 - 10
Display Schematic and PCB ............................... 11 - 18
Surround Schematic and PCB ............................ 19 - 32
Data Schematic and PCB ................................... 33 - 36
S-Video Schematic and PCB .............................. 37 - 40
Video Schematic and PCB ................................. 41 - 44
Input Schematic and PCB .................................. 45 - 50
Component Video Schematic and PCB ............. 51 - 54
HDMI Power Supply Schematic and PCB .......... 55 - 56
HDMI Module Schematic and PCB ................... 57 - 58
Balanced Output Schematic and PCB ............... 59 - 60
Parts List ............................................................ 61 - 74
Repacking Instruction .............................................. 75
CONTENTS
Serial Number XN1001 And Above
SERIAL NO. XN1001 And Above
MX120
A/V CONTROL CENTER
PRELIMINARY

PERFORMANCE SPECIFICATIONS
2
Audio Specifications
Frequency Response
Left, Center, Right,
Left Surround,
RightSurround,
Left Back, Right Back:
±0.5dB from 20Hz-20,000Hz
Subwoofer1:
±0.5dB from 20Hz-140Hz
Total Harmonic Distortion
0.005% maximum from 20Hz to 20,000Hz at rated output
Signal To Noise Ratio
Phono: 86dB below 10mV input (AWeighted)
HighLevel: 96dB below rated output (A Weighted)
Rated Output Voltage
2.5V Unbalanced Outputs (Main)
5.0V Balanced Outputs (Main)
Maximum Voltage Output
9.5V Unbalanced
19V Balanced
Output Impedance
100 ohms Unbalanced
200 ohms Balanced
Input Impedance
Phono: 47k Ohms, 65pf
HighLevel: 22k Ohms Unbalanced
50k Ohms Balanced
Sensitivity for Rated Output
Phono: 5mV
HighLevel: 500mV Unbalanced
1V Balanced
Maximum Input Signal
Phono: 50mV
HighLevel: 5V Unbalanced
10V Balanced
Voltage Gain
Phono to REC Out: 40dB
Phono to Output (Main): 54dB
High Level to REC Out: 0dB
High Level to Output (Main): 14dB
Tone Controls
Bass Control: ±12dB at 30Hz
TrebleControl: ±12dB at 10,000Hz
General Specifications
Power Requirements
100 Volts, 50/60Hz at 65 watts
110 Volts, 50/60Hz at 65 watts
120 Volts, 50/60Hz at 65 watts
220 Volts, 50/60Hz at 65 watts
230 Volts, 50/60Hz at 65 watts
240 Volts, 50/60Hz at 65 watts
Note: Refer to the rear panel of the MX120 for the
correct voltage.
Overall Dimensions
Width is 17-1/2 inches (44.45cm)
Height is 7-5/8 inches (19.37cm) including feet
Depth is 18-3/4 inches (47.63cm) including the Front
Panel and Knobs
Weight
27pounds(12.25Kg)net,46pounds (20.87Kg) shipping
Shipping Carton Dimensions
Width is 25 inches (63.5cm)
Depth is 27 inches (68.6cm)
Height is 12 inches (30.5cm)
1If any of the Channels have the Loudspeaker Setting of
Small, the subwoofer has an electronic low pass filter with a
24dB per Octave rolloff in all modes except external.
1. Unless otherwise noted, all voltages indicated on
the schematics are measured under the following
conditions:
a. ACinputat120volts,50/60Hz.
b.All voltages are +/-10% with respect to ground.
Ahigh impedance(10megaohm)voltmetermust
be used.
NOTES
2. On PC board drawings, Square pad indicates:
a. PolarizedCapacitors-Positive
b.Diodes - Cathode
c. Others - Pin 1
3. WARNING
Parts marked with the symbol have
criticalcharacteristics.Use only replacement
parts recommended by the manufacturer.

MX120
3
SECTION LOCATION
REAR PANEL

4
NOTES

MX120
56
BLOCK DIAGRAM

7 8
BLOCK DIAGRAM con’t

MX120
INTERCONNECT
910
1

DISPLAY CONTROL SECTION SCH 750575
2A
11 12

MX120
13 14
DISPLAY LED SECTION SCH 750577
2B

15 16
DISPLAY KEYBOARD SECTION SCH 750568
2C
2A
DISPLAY CONTROL SECTION PCB 750575

MX120
DISPLAY KEYBOARD SECTION PCB 750568
2C
DISPLAY LED SECTION PCB 750577
2B
17 18

19 20
SURROUND 750570 SCH 1 OF 6
3

MX120
21 22
SURROUND 750570 SCH 2 OF 6
3

23 24
3
SURROUND 750570 SCH 3 OF 6

MX120
25 26
SURROUND 750570 SCH 4 OF 6
3

27 28
SURROUND 750570 SCH 5 OF 6
3

MX120
SURROUND 750570 SCH 6 OF 6
3
29 30

SURROUND 750570 PCB
3
31 32

MX120
33 34
DATA 750572 SCH 1 OF 2 4

35 36
DATA 750572 SH 2 OF 2 And PCB
4