Model Y

Single Syncussion Oscillator with extras

Two Model Y’s syncing and Fming each other, then passing Model F and Model A

So, wait a minute! We have all sorts of clones/replicas/imitations, why what now a single Syncussion VCO on 8 HP? Well, I really like the basic oscillator sound of a syncussion, and I am convinced my modifications add enough value for a sub-circuit spinoff, as it were. Admittedly, the Model Y was originally planned as a complement to the forthcoming Model S, a shaper and splicing module, but the latter still needs a bit more time, so stay tuned…


You get the classic triangle of a single Syncussion VCO with an extra square wave output, both of which are buffered. In the current version TRI is a tad tame, but the version linked below amends that by means of amplification.

There are pots for coarse and fine tuning, a volt per octave input and two extra modulation inputs with some normalisations. Without anything plugged into the Mod1/2 sockets, you can dial in self-frequency-modulation, whereby the square/tri outputs respectively modulate the VCO’s pitch. While the effect is more subtle with tri, naturally, square FM gives you nice new timbres. If you plug an external signal into the respective sockets, the internal signal connection is replaced. Mod 1/2 are less than 1V/Oct and scaled for envelope and LFO modulation – get those kicks and zaps going!

Here are some first clips of a single VCO.

Model Y through VCA – modulated per ENV and LFO
TRI Wave, through VCA, – first some Kicks, then some SYNC
LOUD!!! Square Wave (LOUD) – same as above

In the following examples you hear *two* Model Y’s, with one serving modulation duties and the other playing the main osc. In both examples you hear VCO SYNC and FM from VCO 1 to VCO 2. First example square, second example TRI.

VCO1 SQR syncs AND Fms VCO2 (SQR out)
Stuff gets funny with TRI as sync master and TR as VCO2 out

Of, course, the fun doesn’t end here – oddly, the Model Y responds quite well to being hardsynced with itself and then modulated.

SQR out to SYNC in and modulated by second VCO

Schematic and Gerbers

NB treat R28 (300) offset resistor with grain of salt – you might need less. Best test your tune range without R28 first and then see how it goes. Tuning range w/o CV input should be between something like 20hz and still audible beeeeep.