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.

  • Chris Randall

    Those gummy bears are the ones you get free with every Front Panel Express order. (You can see the panel is still in the FPE wrapping.) One problem with living in Arizona: whenever I order from Front Panel Express, packages come off the UPS truck regularly too hot to hold (the hottest was 163F, according to my kitchen thermometer) and the gummy bears are in a liquid state. So, once it cools, it ends up being a gummy slab. Tastes fine, though.

    • Phil

      Same deal with UPS in ABQ in the summer-our house is at the end of their route, and things are baking hot by the time we get them…

  • pulsn

    Peter, the story is originated from, not

    • Peter Kirn

      The discussion is definitely on the site (and accompanying blog post), and Muffwiggler doesn’t let you see threads without registering and logging in.

    • pulsn

      Noone denies the discussion is there, Peter. But the creator of the OB voice board is not changeling from germany, it is Crow and origin of the pictures and all. Please register and check the source and give Crow, your fellow american, the credits he deserves. Thank you.

    • pulsn

      Scott Rider is his real name, btw. The guy who runs this site:

    • Cillian Warfield

      As an aside, Muffwiggler has temporarily disabled guest browsing due to some forum/server problems. It should be back to normal soon (where you dont need to sign in to view the forum).

  • Theta_Frost

    I think you’d be interested in the DIY Arp 2600 clone, the TTSH.

  • Tim Roberts

    Very glad that there is a new PreenFM coming. I really enjoy mine, but the addition of the midi over usb would be great. I have also in the past run the PreenFM and the Meeblip in unison which makes for some great layered sounds.

  • Joshua Schnable

    There’s this project on the horizon, too:

  • papernoise

    Thanks a lot Peter for mentioning my humble little thumblog! CDM is still my favourite music-related blog, so I’m really glad if I can occasionally spark an idea for a new article.

  • Blob

    “…the Oberheim OB-X, the 1979 polysynth that launched the legendary OB series.”
    No, that would be the OB-1 from 1976.

  • PaulDavisTheFirst

    now if they were talking about cloningthe matrix 12, at a reasonable price, that would be something.

    wait, what’s that? digital modular synthesis is calling me? hang on while i get that …

  • Micheal Clark

    I know this is quality based blogs along with other stuff.