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MODEL 1200 SERVICE MANUAL
TABLE OF CONTENTS
Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
For Years of Dependable Service . . . . . . . . . . . . . . . . . . . .
2
Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2
Service Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3
External Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3
Diagnosis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3
External Fuse Replacement . . . . . . . . . . . . . . . . . . . . . . .
3
Service Access . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3
General Service Procedure . . . . . . . . . . . . . . . . . . . . . . .
4
AC Voltage Measurements . . . . . . . . . . . . . . . . . . . . . . . .
5
DC Voltage Measurements . . . . . . . . . . . . . . . . . . . . . . . .
5
Resistance Measurements . . . . . . . . . . . . . . . . . . . . . . . .
5
Chassis-Mounted Boards and Components . . . . . . . . . .
5
A1 Reverb Pan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5
SHR-11 (and SHR12) Power Amplifier
Board Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5
SHR-11 Potentiometer Adjust . . . . . . . . . . . . . . . . . . 5
VR1101 Output Voltage Offset . . . . . . . . . . . . . . . . 6
VR1102 Driver Balance . . . . . . . . . . . . . . . . . . . . .
6
VR1103 Idle Current . . . . . . . . . . . . . . . . . . . . . . .
6
SHR-12 Temperature Sensor Board . . . . . . . . . . . . . . . 6
VR1201 Temperature Sensor Threshold . . . . . . . . . .
6
SHR-14 Main Board . . . . . . . . . . . . . . . . . . . . . . . . . . .
6
VR1401 Power Amplifier Limiter Threshold . . . . . . . .
7
Rear-Panel Boards and Components . . . . . . . . . . . . . . . 7
SHR-10 Input-Output Board . . . . . . . . . . . . . . . . . . . . .
7
SHR-03 Aux/Mic Board . . . . . . . . . . . . . . . . . . . . . . . .
7
SHR-02 Hi-Z Input Board . . . . . . . . . . . . . . . . . . . . . . .
7
SHR-01 Lo-Z Input Board. . . . . . . . . . . . . . . . . . . . . . .
7
SHR-13 Speaker Output Board . . . . . . . . . . . . . . . . . . 7
B1 Fan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
7
S3 Phantom Power Switch . . . . . . . . . . . . . . . . . . . . . .
8
Front-Panel Boards and Components . . . . . . . . . . . . . . . 8
SHR-04 Channel Board (6). . . . . . . . . . . . . . . . . . . . . .
8
Front Mounting Panel . . . . . . . . . . . . . . . . . . . . . . . . . .
8
SHR-05 Master Control Board . . . . . . . . . . . . . . . . . . . 8
SHR-09 Limiter Board . . . . . . . . . . . . . . . . . . . . . . . . .
8
SHR-06 Headphones Output Board and
SHR-07 Headphones Control Board . . . . . . . . . . . . . 8
SHR-08 Indicators Board . . . . . . . . . . . . . . . . . . . . . . .
8
S2 On/Off Switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
8
A1200MX Input Expansion Module . . . . . . . . . . . . . . . . . 9
Checking Active Components . . . . . . . . . . . . . . . . . . . . .
9
Ferrite Beads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
9
Service Illustrations . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
9
Optional Accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . .
9
Summary of Contents for AUDIOMASTER 1200
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Page 17: ...BLOCK DIAGRAM...
Page 18: ...LEAD CODES...
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Page 25: ...21 CIRCUIT DIAGRAM 1 SHR 01 SHR 02 SHR 03 SHR 04...
Page 26: ...22 CIRCUIT DIAGRAM 2 SHR 05 SHR 07 SHR 08 SHR 10...
Page 27: ...CIRCUIT DIAGRAM 3 SHR 09 SHR 12 SHR 14 23...
Page 28: ...CIRCUIT DIAGRAM 4 SHR 06 SHR 11 SHR 13 SHR 14 24...
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