Using a Korg SQ-1 to trigger.
LOvely sounding filter....12dB-per-octave
VCF that has a range of about 3Hz to 16Hz.
It's CMOS based, using the 4069.
The CD4069UB (unbuffered) consists of 6 CMOS inverter circuits.The digital inverters are used as an op-amps causing distortion and that "dirty" sound we all love.
The "EDP Wasp" was built at end of the seventies by the UK company "Electronic Dream Plant". The designers were Chris Huggett and Adrian Wagner.
The Wasp was probably the world's first battery-operated, portable, digital synthesizer.
Chris Huggett who co-founded Electronic Dream Plant (EDP) also founded the Oxford Synthesizer Company (who made the OSCar).
He is currently a design consultant for Novation .
https://global.novationmusic.com/novation-heritage
Adrian Wagner is the great-great grandson of the famous nineteenth-century opera composer, Richard Wagner.
The sounds of this synth can't only be due to the filter. It has to be due to the combination of the VCOs and VCF; the sound is very impressive. The VCO source is surprisingly analog. A couple of 555 timers!. If I'm reading the schemo correctly, their outputs appear to be converted to digital (four 4013) and then eventually fed into a couple of phase locked loops (4046)
The VCF sounds great when filtering a sawtooth wave, especially if modulated by the LFO random output and Envelope Generator.
The VCF sounds great when filtering a sawtooth wave, especially if modulated by the LFO random output and Envelope Generator.
The modulation controls are unusual in that in the middle position they do nothing. Twisting them clockwise will increase modulation. Twisting them anti clockwise will invert the modulation voltages.
If you ever come across the deluxe Wasp give it a go. Apart from the lovely wooden exterior, it boasts a external input, plus a volume control for each VCO.
Links:
+ CMOS
+ Ken Stones CGS page on the twin CMOS VCF
+ Schematic
+ Jasper - DIY clone of the wasp
+ Muffwiggler jasper build thread