McIntosh MX-134 Service manual

A/V CONTROL CENTER

CONTENTS

Performance Specifications ................................... 2 - 3

Notes ......................................................................... 3

Rear Panel .................................................................. 4

Section Location ........................................................ 4

Block Diagram ...................................................... 5 - 8

Interconnection Diagram .................................... 9 - 11

Display Schematic and PCB ............................... 12 - 19

Surround Schematic and PCB ............................ 19 - 34

Data Schematic and PCB ....................... 35, 36, 39 - 41

SERVICE MANUAL

S-Video Schematic and PCB .............................. 42 - 47

Video Schematic and PCB ................................. 48 - 50

Input Lamp Schematic and PCB ........................ 51 - 56

Component Video Schematic and PCB ............ 57 - 60

Tuner AM/FM Alignment Procedure................. 61 - 62

Tuner/RAA1 Schematic and PCB ....................... 63 - 66

Parts List ............................................................ 67 - 72

Exploded Views and Parts Lists .......................... 73 - 75

Repacking Instruction .............................................. 77

PERFORMANCE SPECIFICATIONS

FM T uner

Useable Sensitivity

14dBF which is 1.4uV across 75 ohms

50dB Quieting Sensitivity

Mono: 19dBF which is 2.4uV across 75 ohms Stereo: 35dBF which is 15uV across 75 ohms

Signal T o Noise Ratio

Mono: 75dB Stereo: 70dB

Frequency Response

Mono: +0, -1dB from 20 to 15,000Hz Stereo: +0, -1dB from 20 to 15,000Hz

Harmonic Distortion

Mono: 0.3% at 100Hz, 0.3% at 1,000Hz, 0.3% at 10,000Hz Stereo: 0.45% at 100Hz, 0.45% at 1,000Hz, 0.65% at 10,000Hz

Intermodulaton Distortion

Mono: 0.25% Stereo: 0.45%

Capture Ratio

1.2dB

Alternate Channel Selectivity

75dB

Spurious Response

100dB

Image Response

75dB

RF Intermodulation

65dB

Harmonic Distortion

0.5% maximum at 50% modulation

Frequency Response

50Hz to 6kHz NRSC

Adjacent Channel Selectivity

45dB minimum IHF

Image Rejection

65dB minimum from 540 to 1600kHz

IF Rejection

80dB minimum

Audio

Frequency Response

Stereo:

Left and Right Small speakers: 80Hz-20,000Hz Subwoofer: 20Hz-80Hz

Left and Right Large speakers: 20Hz-20,000Hz Subwoofer: OFF

Pro-Logic II: (Movie Processing Mode)

Left, Center, Right, Small speakers: 80Hz-20,000Hz Surround Small speakers: 80Hz-7kHz Subwoofer: 20Hz-80Hz

(Music Processing Mode)

Left, Center, Right, Large speakers: 20Hz-20,000Hz Surround Large speakers: 20Hz-20,000Hz Subwoofer: OFF

Dolby Digital and DTS:

Left, Center, Right, Large speakers: 80Hz-20,000Hz Surround Large speakers: 20Hz-20,000Hz Subwoofer: OFF

Stereo Separation

45dB at 100Hz, 45dB at 1,000Hz, 35dB at 10,000Hz

SCA Rejection

65dB

AM T uner

Sensitivity

20uV external antenna input

Signal T o Noise Ratio

48dB at 30% modulation 58dB at 100% modulation

Left, Center, Right Large speakers: 20Hz-20,000Hz Surround Large speakers: 20Hz-20,000Hz Subwoofer: 20Hz-80Hz

External Input

Left, Center, Right, Left Surround, Right Surround: 20Hz-20,000Hz Subwoofer: 20Hz-20kHz (no LP filtering)

Rated Output

All Modes: 2.0Vrms for full bit digital input

Input Impedance

22k ohms

PERFORMANCE SPECIFICATIONS con’t

MX134

Output Impedance

47 ohms at all outputs

Maximum Output V oltage

9.5 Vrms

T otal Harmonic Distortion

0.005% at all outputs

Sensitivity

Analog Input: 400mV for 2.0V output

Signal T o Noise Ratio – All Outputs

Greater than 90dB un-weighted. Greater than 100dB A weighted. Greater than 98dB CCIR.

Maximum Input Signal

Analog Input: 6Vr ms

V oltage Gain

Analog Input to Output: 14Db

Frequency Response

+0, -0.5dB from 20Hz to 20,000Hz

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 MX134 for the correct voltage.

Overall Dimensions

Front Panel: 17-1/2 inches (44.5cm) wide, 7-5/8 inches (19.37cm) high. Depth behind front mounting panel is 21 inches (53.3cm) including clearance for connectors. Panel clearance required in front of mounting panel is 1-1/8 inches (2.9cm).

Weight

32.5 pounds (14.8kg) net, 51.5 pounds (23.4kg) shipping weight

T one Controls

+12dB, -12dB from flat setting

NOTES

1. The heavy lines on the schematic denote the primary signal path.

2. 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.

4 . On PC board drawings, Square pad indicates:

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

5. WARNING

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