Adjustment and Tuning.

Before making any adjustments, allow for a 30 minutes warmup period.
All references to keys implies that C0 is 0v for a 1 volt/octave CV source.

Make sure JP10 has a jumper on the Analog Board (Step 112).
Adding a jumper to JP10 connects the original Pitch Wheel input to ground. If you were to plug a pitch wheel like on a real MiniMoog then this is where you should plug it.

Make sure JP19 has a jumper on the Control Board (Step 3).
JP19 allows you to choose if the VCF envelop output is taken before or after the Amount knob. When you have the MME in front of you, if you place a jumper between the left and middle pins, then the VCF envelop output is taken before the Amount knob. If you place the jumper between the middle and right pins, then the VCF envelop output is taken after the Amount knob.

1. Voltages adjustments.

1.1 Main voltage

  • Connect DC voltmeter to test point TP1 and TPGND. Adjust -10V trimpot (R54) for -10.00v
  • Connect DC voltmeter to test point TP2 and TPGND. Adjust +10V trimpot (R114) for +10.00v

1.2 Oscillator 1 voltage

  • Connect DC voltmeter to test point TP3 and TPGND. Adjust -10V trimpot (R375) for -10.00v
  • Connect DC voltmeter to test point TP4 and TPGND. Adjust +10V trimpot (R119) for +10.00v

1.3 Oscillator 2 voltage

  • Connect DC voltmeter to test point TP5 and TPGND. Adjust -10V trimpot (R373) for -10.00v
  • Connect DC voltmeter to test point TP6 and TPGND. Adjust +10V trimpot (R374) for +10.00v

1.4 Oscillator 3 voltage

  • Connect DC voltmeter to test point TP7 and TPGND. Adjust -10V trimpot (R376) for -10.00v
  • Connect DC voltmeter to test point TP8 and TPGND. Adjust +10V trimpot (R377) for +10.00v

1.5 Envelops voltage

  • Connect DC voltmeter to test point TP9 and TPGND. Adjust +9.3V trimpot (R387) for +9.3v

1.6 Analog Board voltage check points

2. Tuning oscillators.

  • Connect a 1 volt per octave CV/Gate keyboard to the Cv and Gate input jack.
  • Connect a frequency counter to the High Main output jack.
  • Set Tune control to 0.
  • Set Glide Control to 0.
  • Set Noise Level control to 0.
  • Ascertain that all modulation switches are 'off'.
  • Set all range switches to 2'.
  • Set oscillator 2 & 3 Frequency controls to mid-position ('centered').
  • Set all waveform switches to 'sawtooth'.

2.1 Oscillator 1 tuning

  1. Set oscillator 1 Level control to 10.
  2. Set oscillator 2 & 3 Level control to 0.
  3. While holding A2 key, adjust oscillator 1 Range trimpot (R64) for 1760Hz.
  4. While holding A0 key, adjust oscillator 1 Scale trimpot (R66) for 440Hz.
  5. Repeat steps 3 and 4 until no further improvement is attainable.

2.2 Octave range adjustment

  1. Set oscillator 1 Level control to 10.
  2. Set oscillator 2 & 3 Level control to 0.
  3. Press A2 key.
  4. Set oscillator 1 Range control to 2' : 1760Hz.
  5. Set oscillator 1 Range control to 32'. Adjust Octave trimpot R7 for 110Hz.
  6. Repeat steps 4 and 5 until no further improvement is attainable.

2.3 Oscillator 2 tuning

  1. Set oscillator 2 Level control to 10.
  2. Set oscillator 1 & 3 Level control to 0.
  3. While holding A2 key, adjust oscillator 2 Range trimpot (R131) for 1760Hz.
  4. While holding A0 key, adjust oscillator 2 Scale trimpot (R133) for 440Hz.
  5. Repeat steps 3 and 4 until no further improvement is attainable.

2.4 Oscillator 3 tuning

  1. Make sure toggle switch "OSC3 CRTL" is in "OSC3 CRTL/Upper" position
  2. Set oscillator 3 Level control to 10.
  3. Set oscillator 1 & 2 Level control to 0.
  4. While holding A2 key, adjust oscillator 3 Range trimpot (R201) for 1760Hz.
  5. While holding A0 key, adjust oscillator 3 Scale trimpot (R197) for 440Hz.
  6. Repeat steps 4 and 5 until no further improvement is attainable.

3. Audio Voltage Control Amplifier adjustments.

  1. Monitor the High Main output jack using speakers or headphones.
  2. Set oscillator 1, 2 & 3 Level control to 0.
  3. Connect a wire from TP12 and one of oscillator 1 outputs (JP11).
  4. Adjust trimpot VCA-2 (R263) for the minimum audio signal.
  5. Press and hold a key.
  6. Adjust trimpot VCA-1 (R262) for the minimum audio signal.
  7. Remove wire from TP12 and JP11.

4. Filter adjustments.

4.1 Emphasis (resonance) adjustment

  1. Set oscillator 1, 2 & 3 Level control to 0.
  2. Monitor the High Main output jack.
  3. Set filter Cutoff frequency to -1.
  4. Set filter Emphasis control to 0.
  5. Press and hold a key.
  6. Emphasis should start when Emphasis control is between 7 and 8. If not continue to step 7.
  7. Set Emphasis control to 7.5.
  8. Adjust trimpot REGEN (R389) until self-oscillation starts.

4.2 Range adjustment.

  1. Connect a frequency counter to the High Main output jack.
  2. Turn toggle switches KB1/2 and KB2/2 off.
  3. Set Cutoff Frequency control at -1.
  4. Set filter Emphasis control at 10.
  5. Adjust trimpot Range (R390) for 440Hz.

4.3 Scale adjustment.

  1. Connect a frequency counter to the High Main output jack.
  2. Set Cutoff Frequency control at -1.
  3. Set filter Emphasis control at 10.
  4. Set amount of contour at 0.
  5. Turn toggle switches KB1/2 and KB2/2 on.
  6. Press and hold A2.
  7. Adjust Cutoff Frequency control for 1760Hz.
  8. Press and hold A0.
  9. Adjust trimpot Scale (R391) for 440Hz.
  10. Repeat steps 6, 7, 8 and 9 until the filter tracks 3 octaves.

5. Modulation mix Voltage Control Amplifier adjustments.

  1. Set oscillator 3 waveform switch to Triangle.
  2. Turn MOD-MIX control fully clockwise - This set oscillator 3 as modulation source.
  3. Set MOD-LEVEL control to 10 - This fully 'open' the VCA.
  4. Connect oscilloscope channel 1 to TP10 - VCA input. You should observe oscillator 3 waveform.
  5. Connect oscilloscope channel 2 to TP11 - VCA output.
  6. Adjust Offset trimpot (R384) to null any offset.
  7. Adjust Balance trimpot (R367) so that signal on oscilloscope channel 1 and 2 are identical. (If necessary, adjust Initial lvl control (R368) to reduce gain)
  8. Set MOD-LEVEL control to 0.
  9. Adjust Initial lvl control (R368) for a 0v output on oscilloscope channel 2.
  10. Press and hold a key.
  11. While switching OSC-MOD control on and off, adjust Offset trimpot (R384) for no pitch change.