Audio research d 51 d 75 d 75a d 76 owners manual

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PRICE $5.00

INSTRUCTION MANUAL
MODEL D-76A*

POWER AMPLIFIER

* IncIuding Models D-76, D-75A, D-75, D-51.

audio research curnnralsinn

2843 TWENTY-SIXTH AVENUE SOUTH
MINNEAPOLIS. MINNESOTA 55405

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TABLE OF CONTENTS

Section Page
Introduction ......................................................................... 1
Line Voltage Conversion ........... . .................................................... 1
Equipment Packaging .................................................................. 2
Installation & Mounting ................................................................ 3
Operational Connectors 81 Controls ........................................................ 5
System Connection .................................................................... 7
General Operation .................................................................... 10
System Diagnostics ................................................................... 11
Factory Service ...................................................................... 12
Routine Maintenance ................................................................. 12
Specifications ................... .................................................... 13
Circuit Description ................................................................... 15
Parts List ........................................................................... 18
Equipment Servicing .................................................................. 20
DC Bias Balance Procedure ......... i .................................................... 21
AC Balance Procedure ............. " .................................................... 21
Intermodulation Distortion Measurement Procedure .......................................... 22
Power-Up Procedure .................................................................. 23
Troubleshooting Table ................................................................ 24
Voltage/ Resistance Table .............................................................. 26

*Appendix A (D-76)
Appendix B (D~75A)
*Appendix C (D-75)
*Appendix D (0,51)

LIST OF ILLUSTRATIONS

Title Page
Equipment Packaging .................................................................. 2
Equipment Dimensions ................................................................. 4
Operational Connectors & Control Layout .................................................. 5
Input Impedance ...................................................................... 6
Typical Speaker/ Headphone Connection .................................................... 6
Monaural Operation Connections ......................................................... 9
Simplified Schematic .................................................................. 14
Schematic Diagram ............... 1 ............... , .................................... 17
Nominal Power Supply Filter Ripple Waveforms ............................................. 25
Chassis & Tube Layout ................................................................ 28
PWB 82D Component Layout ........................................................... 29
PWB 112 Component Layout ........................................................... 30
PWB 113 Layout (Resistors) ............................................................ 31
PWB 113 Layout (Capacitors) ........................................................... 32
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