Audible stepping in DaisySP phaser


I’m trying to build an Eurorack phaser effect module, using DaisySP’s Phaser. The problem I’m facing is that at low LFO speed or if I slowly modulate the phaser frequency using a knob, I hear audible steps in the modulation of the phaser frequency. I thought I could get away by changing the Phaser to use doubles instead of floats in the frequency modulation part, but without success. Any tips?

Hey sems!
I would be happy to look at this closer with you!

How low of an LFO speed would you need? I just tried


in the phaser example (DaisyExamples → seed → DSP → phaser) and didn’t hear steps. I also tried 0.5 as well (though I don’t hear steps necessarily, this low of a frequency just leads to a detuned effect and not really phaser-like). I hope this is the LFO frequency you were talking about.

This forum allows you to share audio files, so feel free to post a clip of what you are hearing.

As for the knob, could you share the modification that you made to the code? Thanks!

I used frequences below 1hz to hear stepping, but you can also hear it if you manually modulate the phaser frequency using SetFreq. I finally identified the source of the stepping: phaser.cpp uses a DelayLine (DaisySP/phaser.cpp at master · electro-smith/DaisySP · GitHub), whose Allpass method takes an integer amount for the delay. Then, the stepping is when the float is converted to size_t when Allpass is called (DaisySP/delayline.h at 6ad2e5928b1b0af924ae7e6cd23d08967acb8864 · electro-smith/DaisySP · GitHub). I ended up adapting another Phaser which doesn’t use Allpass with integer delay and it works well!


I’m having similar issues with the phaser on my guitar pedal project. Would you mind sharing the phaser you ended up using to solve the stepping issues?

I got some inspiration from this one GitHub - MrBlueXav/Daikrispator: Dekrispator on Electro-smith Daisy platform.
I can send you my code later when I’m home.

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