G-Storm Electro GYRINX, New Eurorack VCF Based On The Synton Syrinx

August 21, 2020 Synth Anatomy Eurorack, Hardware, News 0

With the GYRINX VCF, G-Storm Electro from the US brings the unique analog “vowel” Synton Syrinx filter into the Eurorack format

G-Storm Electro has made a name for itself in the past months/years with recreating old vintage Synthesizers. However, they do not clone the instrument as they used to be but transforms the individual areas into Eurorack modules. Currently, for example, the oscillators and filters of the Roland SH-101, Oberheim OB-Xa, or the Arp 2600 are available as Eurorack modules.

For his new project, he ventures into a very special synthesizer area. The GYRINX VCF is a new filter module that is a tribute to the mythical Synton Syrinx from the Netherlands. The Syrinx was a super unique analog mono synth designed by Felix Visser who got help and advice from the one and only Bob Moog. One of the highlights of this synth was a special format filter based on two resonant bandpass (PEAK) and one resonant lowpass contours.

Wowwww” And “Yeahwa

According to G-Storm Electro, GYRINX VCF is not an accurate clone but 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. It 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 a 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 fixed 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.

In terms of sound, it is unique and is definitely not a filter that you already have in the Eurorack system. If you have all under modulation control, the filter could form 3 formant frequencies characteristic of synthetic human voice sounds. “Wowwww” and “Yeahwa”!

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!