OP·A – A Multitimbral FM Synthesizer Shield for Arduino


Developer Frédéric Meslin has announced a Kickstarter project to develop the OP-A, a multi-timbral FM synthesizer Arduino Shield.

The Arduino is popular open-hardware microprocessor platform. A Shield is essentially a PCB that plugs into an Arduino and gives it new features.

The OP·A is an FM synthesizer shield for Arduino, that Meslin says is “great for chiptune music, custom instruments and art setups”.

Here’s the official project video:

Technical specifications:

  • 4-operator voice structure
  • 14 different algorithms
  • 10 voice polyphony
  • 8 simultaneous instruments
  • 90 internal program memory
  • 16-bit high-quality stereo output
  • Powered with +5V from Arduino
  • 3.5mm jack line-level connector

The OP·A shield is controlled using the Arduino serial port and few additional lines.

The OP-A is available to project backers, starting at €35.

16 thoughts on “OP·A – A Multitimbral FM Synthesizer Shield for Arduino

  1. If it would have a filter i would be all over this,i know it’s not standard in FM synthesis and i guess i could just use on in my daw, but a master filter to tame the harsh fm sounds would be nice when playing live.

    1. Well, if you look at the intent of FM synthesis, it’s to build sounds from harmonics to change timbre. On an analog subtractive synth, the filter serves as the way of changing timbre. Filters don’t always have the most pleasing effects on FM sounds (oftentimes they can increase the unpleasantness) – a decent EQ (with a sweepable mid) is sometimes just enough.

      I believe the PreenFM project had filters? Never owned one so I couldn’t say for sure. Regardless, it would add a fair bit of complexity to the project.

    1. I’m a fan of FM synthesis, and I think that your product looks neat. Love the possibilities the algorithms have!

      Since it sounds possible with how open this project is and how much more power we have today than when we did 20 years ago, do you think it would be possible to have more than just sine waves as operators ala the OPL line?

  2. I think also that some kind of analog filter at the end of the signal chain can be great. Nothing too fancy. Just a static 1 pole at around 10k would remove some nasty high frequencies. It should not add much to the cost.

  3. Anyone recognize which FM chip they are using? Seems to have changed over their development iterations and I don’t recognize the specs… 4 operators, 8 instruments and nice aliasing (suggests 2151) but 14 algorithms /10 voices might be something else. EDIT: manual says it’s a “16 bit microcontroller with DSP extensions”…Looking forward to it in any case.

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