Studer ReVox A77 free download

File name ReVox_A77_serv_man complete.pdf

1. CONTENTS 2. GENERAL 2.1. Front Panel Rear Panel Page 4 5 3. DISMANTLING 3.1. Removal of Housing 3.2. Removal of Cover Panel 3.3. Removal of Front Panel 3.4. Removal of Power Switch 3.5. Removal of Brake Unit 3.6. Removal of Reel Motors 3.7. Removal of Capstan Motor 3.8. Removal of Control Board 3.9. Removal of Power Transformer 3.1 0. Removal of Amplifier Cards 3.1 1. Removal of Potentiometer 3.12. Removal of Switch Board 3.13. Removal of Frame ( Removal of Rotary Switches) 4. MECHANICS 4.1. Headblock 4.1.1. Tape Guides 4.1.2. Head Mounting 4.2. Tape Tension 4.3. Brakes ( Stop 4.3.1. Brake Torque Measurement 4.3.2. Brake Adjustment 4.4. Pressure Roller 4.4.1. Pressure Measurement 4.4.2. Pressure Solenoid Readjustment 4.4.3. Exchange of Pressure Roller 4.4.4. Pressure Lever Readjustment 4.5. Capstan Motor 4.5.1. Removal of Capstan Axis, Ball Bearings Exchange of Reel Motor Bearings 4.6. 4.7. Lubrication 4.8. End-of-Tape Switch ELECTRONICS Switch Board and VU-Meter Board 5.1. 5.2. Input Amplifier 5.3. Record Amplifier 5.4. Oscillator 5.5. Record Relay 5.6. Playback Amplifier Power Amplifier ( Loudspeaker Amplifier) 5.7. 5.8. Power Supply 5.9. Drive Control 5.9.1. Photoelectric End-of-Tape Switch 5.1 0. Speed Regulation, Capstan Motor 5. 6. ELECTRICAL ADJUSTMENTS AND MEASUREMENTS 6.1. Demagnetizing 6.2. Tape Speed 6.2.1. Pick-up Head - Adjustment 6.2.2. Tacho Adjustment 6.2.3. Tacho Adjustment with Cathode-Ray Oscilloscope 6.3. 6.4. 6.5. 6.6. 6.7. 6.8. Playback Adjustment 6.3.1. Azimuth Adjustment, Playback Head, Coarse (Max Level ) 6.3.2. Azimuth Adjustment, Playback Head, Fine ( Phase Method) 6.3.3. Playback Level from Test Tape 6.3.4. Frequency Characteristic, Playback ( from Test Tape ) Oscillator and RF-Adjustment 6.4.1. RF-Voltages and Frequency Checking 6.4.2. Dummy Load 6.4.3. RF-Traps, Record 6.4.4. RF-Traps, Playback Record - Adjustments 6.5.1. Azimuth Adjustment, Record Head, Coarse 6.5.2. RF-Bias 6.5.3. Azimuth Adjustment, Record Head, Fine 6.5.4. Record Level 6.5.5. Record Equalization 6.5.6. Frequency Characteristic via Tape Distortion Factor Measurement 6.6.1. Distortion Factor (via Tape ), VU-Meter Calibration 6.6.2. Noise Voltage ( and External Voltage ) via Tape 6.6.3. Noise Voltage, External Voltage " Before Tape" ( Check) 6.6.4. Erase Attenuation 6.6.5. Crosstalk, Mono 6.6.6. Crosstalk, Stereo Output Voltage Check Wow and Flutter 26 27 27 27 27 28 28 28 28 29 29 29 29 30 30 30 30 30 30 31 31 32 32 32 33 33 7. ACCESSORIES 7.1. Remote Control 7.2. Timing Switch Operation MOD1FlCATlONS 8.1. Rewind 8.2. Switch Noise 8.3. RFI 8.4. Transfer Play Sensitivity 8.5. Replacement of Capstan Motor 8.6. Capstan Motor with Sleeve Bearings 8.6.1. Removal of Capstan Shaft and low-friction Thrust Washer TROUBLE SHOOTING 9.1. Faults in the Drive 9.2. Faults in the Circuitry DIAGRAMS Tape Drive VU-Meter Board Switch Board Input Amplifier Record Amplifier Oscillator Record Relay Playback Amplifier Loudspeaker Amplifier Speed Co