Octave voyetra 8 maintenance manual

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Table of Contents 1 INTRODUCTION ........................................................................\ ....................................................... 4 1.1 TRACKING DOWN VOICES ........................................................................\ .................................... 4 1.2 IS ANYTHING REALLY WRONG ? ........................................................................\ ........................... 4 1.3 DOES THE INSTRUMENT NEED A CALIBRATION ?........................................................................\ .... 4 1.4 CARD SUMMARY ........................................................................\ .................................................. 6 1.4.1 Mixer Card ........................................................................\ ............................................. ......... 6 1.4.2 VCO Card ........................................................................\ ............................................... ........ 6 1.4.3 VCF Card ........................................................................\ ........................................................ 6 1.4.4 DAC Card ........................................................................\ ............................................... ........ 6 1.4.5 DIGIMOD Card ........................................................................\ .............................................. 6 1.4.6 ANAMOD 1 Card........................................................................\ .......................................... .. 6 1.4.7 ANAMOD 2 Card........................................................................\ ............................................ 6 1.4.8 CPU Card ........................................................................\ ....................................................... 6 1.4.9 Pot Panel........................................................................\ ......................................................... 7 1.4.10 Switch Panel ........................................................................\ ........................................... .... 7 1.4.11 Jack Bay ........................................................................\ ..................................................... 7 1.4.12 Power Supply ........................................................................\ ........................................... .. 7 1.4.13 Keyboard ........................................................................\ ............................................... ..... 7 1.5 SIGNAL FLOW DIAGRAMS ........................................................................\ ..................................... 8 2 MIXER CARD........................................................................\ ............................................. .............. 10 2.1 THEORY OF OPERATION ........................................................................\ ...................................... 10 2.2 VCA OPERATION ........................................................................\ ............................................... 10 2.3 HEADPHONES ........................................................................\ ..................................................... 11 2.4 NOISE ........................................................................\ ................................................................. 11 2.5 CALIBRATIONS ........................................................................\ ................................................... 11 3 VCO CARD ........................................................................\ ............................................................... 12 3.1 THEORY OF OPERATION ........................................................................\ ...................................... 12 3.2 VCO OPERATION ........................................................................\ ............................................... 12 3.3 AUTO TUNE FUNCTIONALITY ........................................................................\ .............................. 13 3.4 DC VOLTAGES ........................................................................\ .................................................... 14 3.5 CARD PIN SIGNALS ........................................................................\ ............................................. 14 3.5.1 Inputs ........................................................................\ ............................................................ 14 3.5.2 Outputs ........................................................................\ ................................................ .......... 14 3.6 TROUBLESHOOTING TIPS ........................................................................\ .................................... 14 3.6.1 Step 50-71: Waveform Tests.................................................................\ ................................ 15 3.6.2 Step 72-73: Sync Check........................................................................\ ................................. 15 3.6.3 Step 74-75: Linear FM Check ........................................................................\ ....................... 15 3.6.4 Step 76-79: Modulation Test ........................................................................\ ......................... 15 3.7 TYPICAL PROBLEMS AND SOLUTIONS ........................................................................\ ................ 15 3.7.1 Letter A appears ........................................................................\ ..................................... .. 15 3.7.2 Letter B, C or D appears ........................................................................\ ................. 16 3.7.3 Letter E appears or other pulse width problems .............................................................. 16 3.7.4 No sub octave ........................................................................\ .......................................... ...... 16 4 VCF CARD ........................................................................\ ............................................... ................. 17 4.1 THEORY OF OPERATION ........................................................................\ ...................................... 17 4.2 VCF OPERATION ........................................................................\ ................................................ 17 4.3 CALIBRATIONS ........................................................................\ ................................................... 18 4.4 VCO MULTIPLEXING SYSTEM ........................................................................\ ............................ 19 4.5 DC VOLTAGES ........................................................................\ .................................................... 19

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4.6 CARD PIN SIGNALS ........................................................................\ ............................................. 19 4.6.1 Inputs ........................................................................\ ............................................................ 19 4.6.2 Outputs ........................................................................\ ................................................ .......... 20 4.7 VCF CARD TROUBLESHOOTING TIPS ........................................................................\ ................. 20 4.7.1 Step 00-02: Resonance (Q) Tests ........................................................................\ ................. 20 4.7.2 Step 03: DC Feedthrough Check ........................................................................\ ................. 20 4.7.3 Step 04-11: Initial F c and V/Oct Calibration ....................................................................... 20 4.7.4 Step 11-27: VCO Volume Test ........................................................................\ ..................... 21 4.7.5 Step 28-31: F c & Q Modulation ........................................................................\ ................... 21 4.7.6 Step 32-35: VCO1 & 2 Modulation...........................................................\ ........................... 21 4.7.7 Step 36-39: Noise Audio Path ........................................................................\ ...................... 21 4.7.8 Step 40-43: VCO Bypass VCF ........................................................................\ ..................... 21 4.7.9 Step 43: TL068 Drift Test........................................................................\ ............................. 21 5 DIGIMOD CARD ........................................................................\ ........................................... .......... 23 5.1 THEORY OF OPERATION ........................................................................\ ...................................... 23 5.2 DEMULTIPLEXING ENABLE SIGNALS ........................................................................\ .................. 23 5.3 MODULATION SYSTEM SCAN CLOCKS ........................................................................\ ................ 24 5.4 DEMULTIPLEXING / REMULTIPLEXING ........................................................................\ ................ 24 5.5 MONO CONTROLLER MULTIPLEXER ........................................................................\ ................... 25 5.6 MISCELLANEOUS SWITCHING FUNCTIONS ........................................................................\ .......... 25 6 KEYBOARD ........................................................................\ .............................................................. 26 6.1 THEORY OF OPERATION ........................................................................\ ..................................... 26 6.2 CIRCUIT OPERATION ........................................................................\ ........................................... 26 6.2.1 Power Retrieval ........................................................................\ ........................................ .... 26 6.2.2 Clock/Strobe Retrieval ........................................................................\ ................................. .26 6.2.3 Digital Data Acquisition........................................................................\ ............................... 27 6.2.4 Analog Data Acquisition ........................................................................\ ............................... 2 8 6.2.5 Keyboard Pressure Sensor ........................................................................\ ............................ 28 6.2.6 Joystick........................................................................\ ............................................... ........... 29 6.3 CALIBRATIONS ........................................................................\ ................................................... 29 6.4 KEYBOARD TROUBLESHOOTING TIPS ........................................................................\ ................. 29 7 POT PANEL ........................................................................\ .............................................. ................ 30 7.1 THEORY OF OPERATION ........................................................................\ ...................................... 30 7.2 KEYBOARD CLOCK /POWER INTERFACE ........................................................................\ .............. 30 7.3 KEYBOARD DATA INTERFACE ........................................................................\ ............................ 31 7.3.1 Digital Data Retrieval........................................................................\ ................................. .. 31 7.3.2 Analog Data Retrieval ........................................................................\ .................................. 32 7.3.3 Controllers ........................................................................\ ............................................ ........ 32 7.4 PARAMETER TRIMMER MULTIPLEXER ........................................................................\ ................ 32 7.5 MASTER VOLUME AND MASTER TUNE CONTROLS ..................................................................... 32 7.6 CALIBRATIONS ........................................................................\ ................................................... 33