Pearl SY-1 Syncussion Mods

Update 10/2023: for more substantial mods/info, see my new MSW SY-1 page.

After scoring a mildly battered Sy-1 from a retiring drummer, I became quite obsessed with the design and, of course, also interested in taking that excellent synthesizer’s sound a little further. After implementing separate outputs per channel and CV inputs for pitch, according to Remörk’s instructions, I also added filter cutoff CV. The OG Syncussion schematics were helpful here, as were the scans of the service manual.

As for modifications on that unit, I simply did CV in and separate outs per channel, yet my interest in further mod renewed when tinkering with my Pharmasonic, I checked out a couple of things that should work as well on the SY1/other clones. Heres a schematic with mods added in colour:

some mods for the sy-1

As for the VCO sync modification, check my Parmasonic Sy-Core page for details and an audio demo. CMOS sync sounds rad!

With a couple of clones being around now (THC, Psycox, Michigan Synth Works, and my favourite, the Pharmasonic SY-Core), these mods might look basic (and technically, they are so). Yet, the look and smell of the Pearl PCB is hard to beat – and it’s sound aint a slouch either.

Here are two demos of the Sy-1 in the context of a track (unmodded but with post-processing).

Excerpt 1
Excerpt 2

You can hear here a track made entirely with my Pharmasonic for comparison here.

4069UBs, 2sa798s and styroflex caps at the heart of the Sy-1 VCOs. Had to replace one of those by now obsolete transistors, which was a bit of a gamble (ebayz), but if you need some, Klanggenerator has NOS, and he’s a trusted builder.
Mesh heads before and after restoration
Plastic sunflower makes all the difference
Original warranty certificate from first buyer, who never filled it in.

Here’s an unprocessed demo of all modes of the Sy-1.

Free Sample Pack:

Here you, go – some Syncussion Samples for non-comercial use.

Berfotron’s Super Syncussion

In terms of Syncussion mod stuff, I think it’s hard to beat Ninni Bergfors’ work on a “Super Syncussion,” which expands the presets modes of the original radically and allows for additional tricks like internal filter FM and ring modulation. According to Bergfors’ FB page, the Super Syncussion was auditioned by Teenage Engineering in 2013, but apparently no collab emerged, which is a shame because Ninni is a genius and although great clones, the THC and Psycox sell the snythesis potential of the circuits short (Sy-1M less so). However, Bergfors was so kind as to make all technical documents of the Super Syncusssion public- all we need to do is to grab courage, energy, and a soldering iron… 🙂