McIntosh MA2275 Service Manual

SERVICE MANUAL
Performance Specifications ........................................ 2
Notes ......................................................................... 2
Rear Panel .................................................................. 3
Section Location ........................................................ 4
Block Diagram ...................................................... 5 - 7
Interconnection Diagram .................................... 8 - 10
Main Schematic and PCB................................. 11 - 16
Control Schematic and PCB ............................. 17 - 20
Balanced Schematic and PCB ........................... 21 - 22
Volume/Tone Schematic and PCB ..................... 23 - 26
Data Schematic and PCB................................... 27 - 28
Pushbutton Schematic and PCB ........................ 29 - 30
Amplifier Schematic and PCB............................ 31 - 34
Power Supply Schematic and PCB..................... 35 - 38
Meter Schematic and PCB ................................. 39 - 40
Backup PS Schematic and PCB ................................ 41
Terminal Schematic and PCB ................................... 42
Parts List ............................................................ 43 - 48
Exploded View and Parts List ............................. 49 - 52
Repacking Instructions ............................................. 53
CONTENTS
TUBE
INTEGRATED AMPLIFIER

McIntosh MA2275 Specifications

General

Power Output	75 watts per channel
Total Harmonic Distortion	0.5%
Output Impedance	4, 8, or 16 ohms
Frequency Response	20Hz - 20kHz (+0, -0.5dB)
Input Impedance	47k ohms
Type	Vacuum Tube Integrated Amplifier
Signal to Noise Ratio	90dB below rated output

Summary

Performance Specifications

Block Diagram Explanation

Interconnection Diagram

Main Schematic and PCB

Main Schematic Part 1

First schematic sheet detailing the main circuitry of the amplifier.

Main Schematic Part 2

Second schematic sheet continuing the main circuitry details.

Control Schematic and PCB

Control Circuitry Schematic

Schematic diagram for the control and microprocessor functions.

Balanced Schematic and PCB

Balanced Audio Circuitry Schematic

Volume/Tone Schematic and PCB

Volume and Tone Control Schematics

Schematics for the volume and tone control circuits, including driver stages.

Data Schematic and PCB

Data Interface Circuitry Schematic

Pushbutton Schematic and PCB

Front Panel Pushbutton Schematic

Amplifier Schematic and PCB

Amplifier Circuitry Part 1

Amplifier Circuitry Part 2

Power Supply Schematic and PCB

Power Supply Circuitry Part 1

Power Supply Circuitry Part 2

Meter Schematic and PCB

Backup PS Schematic and PCB

Terminal Schematic and PCB