hi,

I tried to find infos about these effects, but most explantions tell these are all the same effects

althought I used stompboxes in the past and these effects sound way different, especialy phaser

could someone enlight me on this?

I want to recreate a MXR phase 90

thanks

The flanger uses a single delay line which the delay time is driven by a LFO.

The chorus uses a set of delay lines which the delay times are driven by a LFO.

The phaser uses a set of allpass filters which the coefficients are driven by a LFO.

Most of the effects use delay lines (the allpass filter is also a delay line), the difference lies in how to control the delay time range and the feedback.

Here the patches
8_Chorus.pd
7_PhaserMono.pd
6_FlangerMono.pd

@Pierre-Guillot thanks
what do represent the pictures ? is it a specturm or ?

@Pierre-Guillot merci I mean thanks

can you explain what rzero_rev and rpole? I read the help files but I dont really understand it

The pictures represent the spectrograms (sometime called sonograms). frequency X time and amplitude is represented by color.

rzero_rev and role are two lowpass/high pass filters (depending on the coefficients). Used together with the same coefficient, they become an allpass filter. The amplitude response is linear but the phase response varies depending on the coefficient; the phase of frequencies is more or less inverted depending on the coefficient. If you use several allpass filters in serie, more band of frequencies are dephased. If the filtered signal is fed back into the original signal, it generates at set of notch filters and peak filters due to the phase oppositions. The main difference with the flanger is the repartition of the filters (harmonic or not).

You can have a look here: https://github.com/pierreguillot/Fltr. A small set of patches about filters with the filter, their phase responses and their magnitude responses.

And one of the best introduction to digital filters:
https://ccrma.stanford.edu/~jos/filters/

@Pierre-Guillot super thanks
btw is the spectrogram object available in pd, or is it pd-extended stuff or a plugin... ?

@phil123456 You can find everything here:
https://github.com/pierreguillot/Pad
(One of my 100000 repositories...)

@Pierre-Guillot dude, you're the man !! thanks so much

That was a great post Peirre! Thanks for all the information and support