Improved FPGA Synth

A week or so ago we featured an FPGA MIDI interface. Since then the builder has gone crazy with his FPGA and revised his code to include polyphony and PWM output, and posted a polyphony demo.

In our previous coverage of the build, the synth was monophonic, and the MIDI implementation was pretty shaky. After realizing the hard work was done, [Mich] re-wrote the MIDI interpretation module to keep 8 voices in memory. Now the synth can play 16th note arpeggios at 999bpm.

The original build used 8 pins to output the audio with an R/2R ladder for a digital to analog converter. This didn’t work well with a polyphonic synth (everything was clipped or noisy), so [Mich] moved to PWM output.

[Mich] plans on building a PCB for the PWM mixer circuit and adding the ability to receive velocity data from the sequencer. He’s also thinking about adding a sampler to the build, but isn’t quite sure about the best way to implement that. If you have an idea for [Mich], leave it for him in the comments. Check out the video below for a demo of the FPGA synth playing Popcorn.


9 thoughts on “Improved FPGA Synth

    1. I am looking forward to see more information since I do deal with FPGA progging too and like to step into sound synthesis. This seems quite effectiv: Here is a guy pretending to have 4096 voices for a 48kHz samping frequency ready for MIDI use.
      The platform seems fine for music making, since it has 2 audio channels with the option board. Also those 16 switches interest me. They might be used for 16 tap sequencing with direct data input.
      Can you state how many voices you can achive with your platform altogether?
      Did you do some sound quality measuring or estimation to get THD(N) values?

    2. wow, this project seems to have progressed pretty far! From the youtube video it seems to have a full graphical user Interface integrated which I consider being essential for handling an FPGA Music Synthesizer. I will put this Project to my history of FPGA music Synthesizers. Hope to see and hear more from that.

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