slew/unslew filter mod.

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.

Oboe (BoS) p 8

From the book of sounds by David Steven. Click on pic to enlarge!

a. Follow normal two-osc. tuning procedure. Osc. 1 is an octave above osc. 2.

b. Start with output channel 2 level set at 0 (output channel 2 not monitored).

c. Play middle C and advance output Channel 2 level until note breaks up (feedback). Back control off slightly.

d. Play slow glissando from bottom to top of the keyboard tp check that all notes play normally. If any break up or are octave-doubled (i.e. note and its octave), retard the output channel 2 level while holding that note until the note is stable.

This feedback technique adds a considerable number of timbral possibilities to the Synthi A. Experiment with this patch by altering osc. levels and waveform shapes, and filter frequency controls, (filt/osc. 2 output filter). Also increase output channel 2 level by varying amounts and see what happens.