gstormelectro
"I am proud to announce my upcoming GYRINX VCF module.
A eurorack topology of the mythical Synton Syrinx formant filter using AS3350 Alfa re-issue chips.
3 Filters, 4 audio inputs, 3 CV inputs.
And 4 audio path configurations. "
G-STORM ELECTRO Reverb shop
"GYRINX VCF is a filter tribute to the mythical Synton Syrinx.
A BIT OF HISTORY
The Synton Syrinx was an analog monosynth offered without MIDI from 1983. Built in Holland, Syrinx was the brainchild of Felix Visser who sought consultation with Bob Moog. And consequentially distributed by Moog’s Big Briar Inc. The crown jewel of the Syrinx was the unique formant filter section. Comprised of two resonant bandpass (PEAK) and one resonant lowpass contours, all under modulation control, the filter could form 3 formant frequencies characteristic of synthetic human voice sounds. “Wowwww” and “Yeahwa”!
A TRIBUTE TO THE SYRINX
Most of us will likely never see the fabled Syrinx in person. GYRINX VCF is not a clone - rather a painstakingly realized design informed by the known original topology of incomplete schematics, datasheets, and designs from other synths of the era using the CEM3350. Along with the 4 different input/filter signal path routings, the GYRINX VCF is the closest mere mortals will get to the esoteric Syrinx filter experience.
FEATURES
GYRINX VCF has THREE audio filters arranged in a specific configuration: two 2-pole resonant PEAK (bandpass) filters and one 4-pole resonant LOWPASS. 2 CV inputs and a keyboard tracking CV ensures generous range of beautiful and strange formant frequencies you’ll not get with any other filter. The four audio inputs can be configured as a mixed sum, or as a split pair. Also, as with the original, the filter routing options include series and parallel paths. The entire audio signal path is all analog, however filter routing is digitally controlled by the momentary switch.
FEATURES
TWO Alfa AS3350 re-issue filter chips based on the CEM3350 design.
FOUR audio signal input jacks w/ individual attenuators.
Two selectable audio input Types: 1-4 Summed Audio, or 1-2 / 3-4 split audio pair
Two Resonant Peak Filters, does not self-oscillate
One Resonant Lowpass Filter, does not self-oscillate
Two selectable filter configuration Types: SERIES Peak -> Lowpass, PARALLEL Peak || Lowpass
Digitally controlled routing of the all-analog audio path.
Two Control Voltage input jacks for Frequency CUTOFF w/ signal attenuators, routed to both filter types. These offer inverted and non-inverted control.
One Control Voltage (KB) input jack for Frequency TRACKING w/ signal attenuators, routed to both filter types. This one is non-inverted only, and can be used with other mod signals, LFOs, envelopes, gate, or anything else!"
