Using an FPGA for music


So Novation have used FPGAs, I believe the Modal 001/002 must be using one too.

So has anyone considered getting a MiST FPGA computer (typically used for recreating old computers/consoles) and doing some musical applications with it?

I guess the one major flaw with it is no audio input, which makes doing FX processing with it a bit more involved.


A FPGA might be good for emulating the sound chips of 8-bit consoles. I’m not sure what other applications they would have an advantage over the usual microcontrollers and ARM boards.


Audio synthesis at very high sample rates. With a sample rate in the MHz range you no longer have to bother with aliasing issues. The 25th harmonic of a note at the top of the audible range will still be below Nyquist. It’s very easy to code complex interactions between oscillators. Kind of brute-force-ish!

That’s how they are used in the Novation Peak and in the Intellijel/Cylonix Shapeshifter module.

Modal seems to use good old AVRs, one per oscillator, in a tight loop (in the 600-1000 kHz I’d say).


What about filtering, would that be possible in the digital domain with a nice sound? or would you effectively be building a mini DSP to run some filtering algorithm?


Have a look at the Novation Peak. Very high fidelity oscillators, both subtractive and wavetable. With multiple FX and a very very long reverb, plus audio rate modulation on pretty much every parameter.



Of course! And you don’t even need to emulated a DSP, you can just “hard-code” the filter equations with multiplier and adder blocks.


Now that’s a good use of FPGA :slight_smile:

SwinSID was a good effort, given the use of an AMTEL, but FPGA sounds like the perfect way to do it. The C64DTV did SID but without filter.


I’ve heard it said that a lot of the character of the SID was the (analogue) filter and a lot of the character of the filter was down to the somewhat shonky silicon process they were using to make the chips.
Apparently copying the topology with discrete components doesn’t get you there and people have had more luck with digital modelling of the filter. I can’t remember where I read this though.


The character of the SID wasn’t really the filter as not that many tunes use it, due to major variations in the cutoff.

I’d say the character is just the low-fi nature of it. But also the fact it had someone with a passion for music designing it.


Because I recently bought the MiST computer and was pointing out that if you want to do some FPGA programming then there’s any easy way to get a computer for that job :slight_smile:


Given your name I’d expect you to know better than me!