When high frequency controlled voltages are applied to the unmodified Synthi filter they are low-pass filtered by the C31 capacitor. This means that the filter will not respond to high frequency CVs, and respond slowly to rapid changes in incoming CVs. The switch removes C31 cap. from the CV input circuit, so the filter will respond to high frequency controlled voltages.

All modifications are at your own risk and the synthi assumes no liability for personal injury caused or damage to equipment or loss of use caused directly or indirectly by the use of these plans.