Synton 3000 Series Modules

Synton is a Dutch company that made the 3000 series modules in the 1980s. A complete listing of modules can be found at

I have done repairs, modifications, conversions, and assembly/builds for these modules.

3005 EGR (ADSR)

3006 MPL (1 CV in to 4 CV out with attenuators)


3015 MXA (4 input mixer)

3017 VCF (2 pole state variable filter)

3209 2VCA (Dual VCA)

3218 INV / SLR (Dual inverter/offset and slew limiter)

3022 Binary Divider (Divide by 2/4/8)

3224 Hi/Low Pass VCF

3233 S&H / LFO

3235 ENV / CPR (Envelope follower, comparator, and trigger delay)


The modules have a fairly standard grid layout and the panel size is 128.5mm high by 81.3mm (16 HP) wide. The modules operate on +/-15V. They have a fairly standard front panel PCB for mounting the potentiometers, banana jacks, switches, and LEDs and are drilled for the various modules.  This panel PCB has been drilled for 4 potentiometers and 6 banana jacks.


For the modules I assembled, I used the original Multicomp 24.247 series banana jacks. It consists of a barrel with a screw-on front and a shroud. The shroud fits on the back of the panel and the PCB is tightened against it holding the PCB to the panel. The potentiometers do not fasten to the panel.

The original construction had the nuts soldered to the PCB. I tried this but it took so much heat that it started to deform the plastic pieces. Once deformed the banana jacks were no longer tight to the panel. In fact some were so loose that I had to apply a bit of super glue to fasten them together.

I decided instead to solder a wire from the rear of the banana jack to the PCB. I had to solder this wire with the plastic pieces removed. The plastic cap screws on tight but it is difficult to tighten the banana jacks sufficiently. I bought some additional 1/4-28 nuts to double nut them for a more robust construction.



Blacet Research 19" Rack

Here is a completed set of modules I assembled into a Blacet Research rack. I made end panels to fill the unused space.



Non-Synton Module Builds and Custom Cabinet

I was asked to expand the Blacet Research rack with additional Synton-format modules. I repaneled a Blacet 2100 and MiniWave and built a Jürgen Haible Frequency Shifter and a custom Preamp/Envelope Follower into narrower Synton panels to fit the remaining rack space. I repaneled the custom Frac WAD I built earlier into a standard size Synton panel. The new modules required a deeper rack than the Blacet so I made one with a Hammond 10.5 x 17 x 13 inch chassis RMCS191013BK1.

Synton-format WAD and narrow Synton-format Blacet 2100 and MiniWave

Narrow Synton-format Jürgen Haible Frequency Shifter

Narrow Synton-format preamp/Envelope Follower


This photo is the new Hammond chassis with the 4 new modules added..


There is plenty of room inside.



3.5mm Jack Conversion

I was asked to convert 6 modules to 3.5mm. The panels are held on by the banana jacks and the rear nuts are soldered to the PCB. The only way to remove the jacks is to unscrew the front plastic cap which was glued on. I could then disassemble and remove the jacks. I needed a new way to mount the PCBs and decided to replace the aged potentiometers with 3/8" bushing 16mm Alpha potentiometers which would mount from the front and with four would result in a sturdy module.

This photo shows the PCB mounted to the potentiometers. The 3.5mm jacks fit nicely in the space between the PCB and panel and I simply wire through the holes to the pads. A ground wire to all jacks connects to the PCB ground trace.


The 3209 2VCA only has two potentiometers so I made a flat bracket between the bottom two 3.5mm jacks to mount a standoff to support the PCB bottom. The 4022 Binary Divider has no potentiometers so I made a right angle bracket and mounted the PCB by the banana holes using nylon hardware.


I had to replace the knobs since the original were push-on for a D shaft. The owner wanted colors and the conversion came out quite nice.


Here is the completed cabinet with all 6 modules. I converted the Banana>3.5mm module into two 1x4 multiples. The banana holes were too large for 3.5mm jacks so a single turn of solid wire wrapped around the bushing took up the extra space.