Re: [SynthModules] Re: Quantizer for non 1V octave VCOs
2004-02-24 by Andrew Scheidler
For sure dude. Microtunings RAWK! Gotta dig out my Gamelan scale frequencies... http://www.ph.k12.in.us/~drew Andrew >>> mmarsh@websense.com 02/24/04 12:55 PM >>> Which brings to mind microtunings! Mike --- In SynthModules@yahoogroups.com, "grantrichter2001" <grichter@a...> wrote: > Just a thought, > > The PSIM can also serve as a quantizer for non 1V per octave > VCOs. > > For example the Buchla 258s have roughly a 2.5 volt per octave > responce. So the 10 volt output of the PSIM would cover 4 > octaves. 2.5 / 12 = 0.208 millivolts per semitone. That translates > to 80 DAC counts per semitone instead of 32. > > To make a chromatic quantizer for a Buchla 258 the equation is > > DAC1V = (MIDINOTE-MIDIOFFSET)*80 > > Use the coarse and fine scale controls on the 258 for precise > tuning. > > For EML synths with a 1.2 volt per octave scale, one semitone = > 100 milivolts. For EML synths use > > DAC1V = (MIDINOTE-MIDIOFFSET)*38 > > the actual number is 38.5 so for EML some tweeking of the DAC > voltage reference may be needed for perfect tune. > > I don't recall the EMS Putney and Synthi numbers, they are less > than 1 volt per octave, but the same technique applies. Just > adjust the number of DAC steps to match the target synths volts > per semitone number. Be sure to check out the primary Web site at: http://www.SynthModules.com Yahoo! Groups Links