What's this ?

 PreenFM is a set of electronic components and C++ files that, 
when put together become a Frequency Modulation sound module.
(Its FM synthesis is not at all based on any Yamaha FM chip.)


2012 June, 3 new demo tracks
- Those 3 tracks have been mixed using only EQ, compressor and pan, drums are not PreenFM -

VST mdidi plugin for Win32/64 and Osx
to control all PreenFM parameter from you Daw

"I’m no synth lightweight, I have over x20 hardware synths, mostly analogue.... 
The Preen is a really good FM synth. I have an original DX7 & prefer the Preen.....
I went into it for a build for fun & ended up with a professional sounding synth.."
Jason Last

The PreenFM with firmware 2.00, main features include :

. 9 different FM alogorithms with up to 6 operators
  Each operator includes one oscillator and one ADSR enveloppe
Oscillator : 7 waveforms (4 sin variation + noise + square + sawtooth), 
  linked to keyb freq or fix, fine tune

.  Up to 8 voice polyphony with 3 operators FM algoriyhm
   up to 6 voice polyphony with 4 operators FM algoriyhm 
   and up to 4 with 6 operators FM algoriyhm.

. Glide available when voice set to 1

6 LFOs routable in the modulation matrix
. 3 standard LFOs (5 waveforms (sin, saw, ramp, square, random), 
frequency in Hz or synced to external MidiClock (/16, /8, /4, /2, *1, *2, *4, *4, *8)
ramp up to 4 seconds, reset on new note).
. 1 Env type LFO
. 2 Step sequencers (16 steps) - BPM from 10 to 240 or synced to MidiClock (/4, /2, *1, *2, *4)

. 12 rows modulation matrix - 15 different sources and 42 destinations

. Gate effect  (kind of) available in matrix destination - step sequencer routable

. 4 user banks of 128 presets

. System exclusive to exchange patches and banks with a computer
. Midi control : 44 control input/output control changes linked to parameters
. Nrpn : input/ouput of all paremeters
. Midi thru allow to insert the PreenFM in a MidiChain.
 PreenFM Midi channel selectable
. Can send CC to external gear from modulation amtrix

. Large readable 4x20 LCD

. Friendly surface controle : You always clearly see on the screen what you're currently editing

. Sampling rate : 32768 Hz (Makes integer division faster ;-). Pseudo 11 bits.
    1024 Hz for LFO and modulation matrix

. 6th order butterworth analog filter to convert the 1 bit output into a nice waveform

. Transparent case that allows you to see every day your nice work

. A PreenVST to control your PreenFM sound module from within your sequencer
  (currently exists for OSX and win32/64 VST versions)

"Received the kit and I must say you did a FANTASTIC job laying out the parts, providing clear instructions, and choosing high quality materials for the build. This is a quality job fromtop to bottom! Thank you! I built it last night in two hours."

Presets-based demo - 1.0x firmware

"Just received and built mine, Totally awesome, love the open architecture of the synth, multiple algorithm programs is really nice.
Has a great signal to noise ratio and a very user friendly interface! 
Small enough to carry around, so it's going to be an intense FM sound design weekend!"  

New firmware - Step sequencer demo

PreenFM firmware 1.51


"I am a big fan of vintage FM synths.  I have quite a collection of them, and have worked with most of them with sound programming.  
I have a DX 100, TQ5 and a Sharp X68000, and most of the 4 ops and OPL synths sound pretty much the same.  
This one is totally different, has a different sound, and it's really good.  It can sound super harsh, and ridiculous, but also really soft and sweet.  I'm actually thinking about learning how to code to work on this guy.  
I really like that it is also polyphonic, so far the only diy synth that does polyphony!"

PrenFM is open source and open hardware

That means that you can take the source code, modify it, compile it,  and upload it into the flash memory of your PreenFM.
That means that if you want a custom case, take the map schema, change it and order one on Ponoko.
I learnt many things looking at other open DIY project, i hope some people will learn somethings doing or just looking at this one.

If you improve anything, don't forget to share.
Hardware is protected under a Creative Common license, and the code under GPLV3.


"I received the synth today in the mail, and just finished it about an hour ago and gotta say, it rocks. 
Good Job man.  I have built quite a few of these DIY synth boxes and this one is definitely one of the best.
Good documentation and overall a great sounding synth."

Aerodynamic Shape :-)

"All went well and really fast. the resistor sheet saved some time, too.
great project for beginners i think."