McIntosh MX-120 Service manual

MX120

A/V CONTROL CENTER

SERIAL NO. XN1001 And Above

PRELIMINARY

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

CONTENTS

SERVICE MANUAL

Serial Number XN1001 And Above

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

PERFORMANCE SPECIFICATIONS

Audio Specifications

Frequency Response

Left, Center, Right, Left Surround, Right Surround, 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 (A Weighted) High Level: 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

Maximum Input Signal

Phono: 50mV High Level: 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 Treble Control: ±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

Input Impedance

Phono: 47k Ohms, 65pf High Level: 22k Ohms Unbalanced

50k Ohms Balanced

Sensitivity for Rated Output

Phono: 5mV High Level: 500mV Unbalanced

1V Balanced

1. Unless otherwise noted, all voltages indicated on the schematics are measured under the following conditions: a. AC input at 120 volts, 50/60Hz. b.All voltages are +/-10% with respect to ground.

A high impedance (10 megaohm) voltmeter must be used.

Weight

27 pounds (12.25Kg) net, 46 pounds (20.87Kg) shipping

Shipping Carton Dimensions

Width is 25 inches (63.5cm) Depth is 27 inches (68.6cm) Height is 12 inches (30.5cm)

If 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.

NOTES

2 . On PC board drawings, Square pad indicates:

a. Polarized Capacitors - Positive b.Diodes - Cathode c. Others - Pin 1

3. WARNING

Parts marked with the symbol have critical characteristics. Use only replacement parts recommended by the manufacturer.