Adding dsp tone control to guitar pedals

I have now made a couple of different audio effects for guitar and bass on the terrarium platform but have never added a tone control to these projects. What type of filtering and over what range is common. By the looks of things, tonestacks in analog pedals tend to employ more complicated filtering than just singular hp or lp filters.

Applications i have in mind which may require different approaches are:

  1. Global tone control for a bass compressor+overdrive project
  2. Tone control for a delay to shape the tonal characters of the echos

Let me know if anyone has any useful resources or tips regarding this design problem

You’re probably looking for a digital low-pass filter. The simplest solution is a one-pole IIR (there’s a DaisySP class for this, I think).

Depending on the sound you’re going for, that filter could be at the output, or in the delay line (so that subsequent echos get progressively damped).

For a more subtle effect (especially in the feedback loop), you could try out a filter with a zero at Nyquist, e.g.

y[n] = 0.5 * (x[n] + x[n-1])

I’ve since found this which is more in line with what im looking for

For any future people with the same issue, i found these

And this in faust library

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Did you adapt these to use in pedals with other DaisySP stuff?

Not yet! idk about the faust one but option one looks doable

they both are derived from the same research paper so with that and these code examples im sure i can work it out. Perhaps i will share here if i get it working