Thanks @David for your tireless answers! I have seen @katjav patch but it doesn't respect my requirments and targets.

Has anyone ever thought that it could be nice to be able to see solutions proposed by users without they use writing as follows?

[pdobject] [pdobject2]
| |
|
[pdobject3]

?
Can we discuss to develop a software engine that takes let user writes on a canvas his patch? The tool can take a *.pd file in input and translate him in a graphical version of the patch.
What do you think about it?

Hello to everyone! Thanks to David for the suggests.
I'm working at the patch using the [notch] element by ggee external library for design the filter.
How can I put in series 2 or 3 notch elements in series to create the bank of filters?

Thanks in advance.
Here my patch.
main.pd

Thank you, David for your precious support.
My target patch is to simulate a "Phase Shifter" like the guitar Boss pedal for my personal use. It is a Delay-Line effect, so it could be more complex.
Anyway, I want to realize the delay line with 3 different notch filter in series but I want to design it with with only one, initially. I will try to increment them after. My idea is as follows: the single notch filter is controlled by an LFO with 4 parameters: the center frequency, the bandwidth (Q Factor) and the amplitude (Resonance). The 4th one is the Stage, but I will develop it in a second time . The input of the patch will be a keyboard MIDI control.
Refferrals:

Can you help me?
Thanks in advance.

Hello to everyone!

I want to realize a PD patch which can simulate the typical scheme of the "Phase Shifter", or rather with a 3 notch filters bank with their variable center frequency. How can I implement a notch filter?

Thanks in advance.