Build Your Own FM Synth

XFM2 is a 64-voice, 2-part, 6-operator FM Synth with effects      24/02/20

The XFM2 Synthesizer Module is the second generation of the XFM Synthesizer Project. XFM2 is a 64-voice, 2-part, 6-operator FM Synthesizer with built-in effects processor, built on an FPGA chip. This is what designers FUTUR3SOUNDZ has to say about it...

FPGA power-up
Stepping up from the Xilinx Spartan-6 used in XFM, XFM2 is based on the Xilinx Artix-7 35T FPGA chip. With almost four times the capacity, of the previous one, this new chip offers plenty of space for a more complex build.

24-bit DAC
Also stepping up from XFM, the simple 16-bit digital-to-analog converters have been upgraded to a 24-bit dedicated chip, with high-end output filters. The analog outputs have then greater dynamic range, higher S/N ratio and lower distortion.

Simplified build
The build is based on two pre-assembled development boards: the Digilent CMOD A7-35T (FPGA, USB, SRAM) and the Adafruit UDA1334A (DAC). This combination allows to get the module running in less than 10 components (about $99 total cost).

Feature Set

  •     2-part, 64-voice polyphony (32-voice for each part)
  •     Polyphonic/Monophonic Legato modes
  •     The two parts can work as individual synthesizers, or layered
  •     6 operators per voice
  •     2 independent oscillators on each operator
  •     8 waveforms per operator
  •     Variable modulation algorithm (extended from XFM to allow for multiple feedback loops)
  •     A 7-segment, loopable Envelope Generator for each operator
  •     (DAD1D2SR1R2, with time and level controls for each segment)
  •     7-segment loopable Pitch Envelope Generator
  •     Per-voice LFO with Triangle, Square, Sine, Random waveforms
  •     Per-operator adjustable LFO sensitivity for pitch and volume
  •     Per-operator adjustable velocity tracking, keyboard tracking
  •     Polyphonic /Monophonic portamento
  •     Pitch bend range adjustable independently for up and down directions
  •     Extensive MIDI implementation (pitch bend, mod wheel, aftertouch, sustain pedal, breath ctl, foot ctl, volume, pan, chorus, reverb, delay, tremolo, etc.)
  •     Four per-program assignable Performance Controls, which allow any parameter to be controlled by MIDI continuous controls messages.
  •     All synthesizer and effects parameters (300+) adjustable via MIDI system exclusive messages.
  •     Two complete stereo-in/stereo-out effect processors (one per part), including:
    •         Decimator
    •         Bitcrusher
    •         Filter
    •         Chorus/Flanger
    •         Phaser
    •         Amplitude Modulator
    •         Delay
    •         All of above effects can be run simultaneously, for both parts
  •     Stereo Reverb with individual sends per part
  •     Arpeggiator
  •     128 programs memory (EEPROM)
  •     MIDI in, optional thru
  •     Samplerate-grade modulations
  •     24-bit stereo analog out
  •     Optional Stereo, 24-bit SPDIF digital out
  •     Battery friendly, low power operation
  •     Fully programmable (connecting it to a PC via USB)
  •     Nearly zero  latency (< 0.5ms)
  •     Extremely fast boot time (< 100ms)

Pricing and Availability:

About $99

More information:





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