Moog Mother 32 VCO pitch, keyboard tracking and Glide problems
Posted: Sun Apr 18, 2021 12:31 pm
Can anyone assist with the problems I am having with my Mother 32. Please see details below:
Unstable VCO frequently.
The frequency of the VCO is unstable. For example a C4 which should be approx 261Hz is constantly moving by approx +/- 10 to 15 cents. The frequency movement can sometimes be by more than this amount, almost by up to +/-a semitone and therefore be very noticeable. It is as if the VCO frequently is being modulated by a LFO at a varying random freqency and random amount. This frequency movement happens regards of which note is played.
It is not possible to calibrate the M32 with any accuracy as the with a constantly changing VCO frequency. Both VCO and VCF modulation are fully CCW / negative so not modulating the VCO. I am playing a sawtooth with the cutoff fully CW.
Keyboard tracking.
I should be able to play a chromatic scale using the M32 keyboard but cannot. With no patch cables connected - When a scale is played (from C to C) the range of notes played is acctually C to approx F#. Play a 2 octave change in note ie C4 to C6 then actual note played by the M32 is a 1 octave range - from Ç4 to C5.
It is only possible to get a correct 1octavce scale by connecting the M32's own KB out into the M32 1 volt / oct input. With this patch in place it is possible to play almost an octave up or down in tune. Play any further than this range the inaccurate pitch tracking mentioned above becomes very noticeable.
Glide. This is constantly on even when the glide control is fully turned CCW / negative. If I play notes 1 octave apart a short portamento glide can clearly be heard
Any suggestions would be appreciated.
Unstable VCO frequently.
The frequency of the VCO is unstable. For example a C4 which should be approx 261Hz is constantly moving by approx +/- 10 to 15 cents. The frequency movement can sometimes be by more than this amount, almost by up to +/-a semitone and therefore be very noticeable. It is as if the VCO frequently is being modulated by a LFO at a varying random freqency and random amount. This frequency movement happens regards of which note is played.
It is not possible to calibrate the M32 with any accuracy as the with a constantly changing VCO frequency. Both VCO and VCF modulation are fully CCW / negative so not modulating the VCO. I am playing a sawtooth with the cutoff fully CW.
Keyboard tracking.
I should be able to play a chromatic scale using the M32 keyboard but cannot. With no patch cables connected - When a scale is played (from C to C) the range of notes played is acctually C to approx F#. Play a 2 octave change in note ie C4 to C6 then actual note played by the M32 is a 1 octave range - from Ç4 to C5.
It is only possible to get a correct 1octavce scale by connecting the M32's own KB out into the M32 1 volt / oct input. With this patch in place it is possible to play almost an octave up or down in tune. Play any further than this range the inaccurate pitch tracking mentioned above becomes very noticeable.
Glide. This is constantly on even when the glide control is fully turned CCW / negative. If I play notes 1 octave apart a short portamento glide can clearly be heard
Any suggestions would be appreciated.