FMmmmmmmm.... it's a new version of the open source PreenFM kit, which the creator says is on-track for fall. Courtesy PreenFM, on Facebook.

FMmmmmmmm…. it’s a new version of the open source PreenFM kit, which the creator says is on-track for fall. Courtesy PreenFM, on Facebook.

It’s a new golden age for synth lovers, past meeting the future and so on. At least, we have a stunning number of wonderful toys. And the DIY community is coming up with a number of particularly special creations.

Take the terrific open source PreenFM, an original, 6-operator FM synth that’s entirely open source hardware (code and schematics).

On Sunday, we learned what creator Xavier Hosxe has in store for the new model:

PreenFM2 status

What’s new in the firmware ?
. Stereo (per carrier operator)
. Multitimbral * 4
. 8 to 16 voices (twice preenFM1)
. Midi over USB (in and out). Din5 still available.
. DX7 sysex bank import (don’t expect miracle but a good starting source to create new source).
. 4 steps envelope (level + time / DX7 like)
. Full floating point engine
. Huge number of preset banks (stored on USB stick)
. 27 FM Algorthms (schemas show up on LCD)
. Dedicated bootloader (3 ways of flashing new firmware : USB stick, sysex, DFU).

Same hardware as the original PreenFM except :
. DC 2.1mm for 7.5V or 9V wall adapter.
. Pins available for expansion
. USB stick to store presets, DX7 sysex files, firmware.
. STM32F4 based (168 or 192Mhz when supported by the chip)
. 2 audio jack
. Real DAC : 2 x 18bits (12+6)

On track for a release in October/November

There’s no new video or audio, but we can still enjoy some 1.5 firmware features (including the step sequencer) for a taste of the instrument:

More info and build instructions on their site.

And under the hood, this fascinating platform:

If you’re okay with fabbing the PCB yourself, you can make it even though it’s out of stock. Otherwise, it’s a kit. (It’s covered, by the way, by the same licensing scheme that our MeeBlip uses, though there’s not yet a ready-to-play model of the PreenFM – this is kit territory.)

By the way, PreenFM was spotted alongside MeeBlip in a lovely build combining the MeeBlip micro and PreenFM into a single synth. I just have no idea who did this, other than it was briefly for sale on the Czech Anyone who knows the story of this synth (or managed to acquire it), do get in touch!

Have you seen this synth? We'd love to hear from you. Cool idea!

Have you seen this synth? We’d love to hear from you. Cool idea!

All spotted via the terrific Tumblr of our friend papernoize. (I knew I got on Tumblr for a reason.)

In other news, someone has the truly crazy idea of recreating a polyphonic synth for these times, cloning none other than the Oberheim OB-X, the 1979 polysynth that launched the legendary OB series. has the full story:

Oberheim OBX Clone (DIY)

So far, the creator – going by the name “Crow” – has gotten as far as a working voice card, which could also be a drop-in replacement for an existing OB-X in need of one. You can read about the process, and a debate over whether this is a good project, on’s forums (in German):

Oberheim OBX Klon


And that front panel should make you hungry for OBX (well, that and some gummi bears):


Good times. I’m really keen to hear how these projects progress, so feel free to bug us here in CDM headquarters, or we can share a beer – or Haribo snack.