John Bowen Synth Design

Hi everybody,
I was trying to explore the comb filter and i found something strange :

0. Unplug midi if you have to.
1.Reset the solaris to be sure.
2. Begin with the usual John's Init Patch.
3. On the filter 1 section, choose :
Type : Comb
Mode : Tube
Cutoff : 0
Res : ( 37% ) but it's not necessary ( more audible )
4. On the filter1 mod section put the Source 1 Amount at 0.
5. Play some notes on the bass part ( no more than 10 )
6. Repeat now a C5 ( for example ) at least 10 times.

You can here the 10 bass notes you have played before wich are repeated with your C5.

I think it has something to do with the polyphonic's gestion, it seems strange and abnormal to me but perhaps is there something i don't understood ?

Yes, this is easy to explain (and it is functioning correctly):

So, the "Comb Filter" is not a filter in the classic sense, but rather, a delay line. When you play notes with a tuned pitched source (such as Osc 1 in this INIT patch example), you are loading the delay line/comb filter for each voice with pitched data. So, each delay line retains the data for the voice until it gets selected again as a new voice. Then the frequency gets loaded again, but you will hear the initial delay line load before it gets the new note. If you did the same test as you describe, but apply some Glide at 100 ms or more, you will hear the action more clearly. Playing notes in the lower end loads the delay lines with those frequencies, and then when you play any notes in the upper registers, you hear the transition.

Another way to check this is to change the audio input of the Comb Filter to white noise instead of Osc 1 (or select Noise as the Osc 1 waveshape). Here the loading of the delay line values will be not pitched, and you will note you don't notice the same result as you described.

Thank you John, you explain it very well.
So it´s not a bug....only a consequence of the way polyphony is managed on Solaris.
That´s not the first time i get trap because of that.....remember me the s/h problem.
The truth is it´s the first time i have a synth working like that, but it´s the first time i have a synth with such a brilliant architecture, i figure it was'nt possible to choose another way.