DSP Robotics Support

Hey StereoSpace! Thanks for your kind comments.

Please go ahead and do whatever you want with this. I'd be interested to see the result but there's no obligation to upload it, just have fun! I just make stuff for the craic, a hobby, and I know the GUI's are always lacking but that's not my main interest.
Regarding the filters, I just tend to use anything I find that works. If you ask Martin Vinacek he may be able to offer optimisations; he's the man for filters believe me. As for the routing why not just use some Selector Prims and a switch to select serial/parallel? I tried out both routings and some of my stuff has them in parallel and some in series so it's a good idea maybe to offer such a possibility.

Cheers

Spogg

Thank you for quick response! How to finish the design, I will show you the result))
As for the selectors I also thought, and tried it, but for some reason, sometimes when you switch modes, the plugin stops producing sound, and generates a low frequency signal.
If Martin Vinacek help, it will be grandly))))

I think MyCo optimized these (and many other) filters in a SM forum thread.

http://vtdevelope.clan.su/FATONE_SSKIN.png

Skin is ready for 50%, it remains to redraw all the items in 3D, and you can use it.
I for myself replaced WaveDraw Osc to WaveTable Osc.
the only thing that angers, this CPU at 40% while playing arpeggios with all enabled oscillators

I can only say and also

That's just SO impressive!

Cheers

Spogg

Below are optimized versions of two apparently popular filters.
EDIT: bug fixed in SVF3.

martinvicanek wrote:Below are optimized versions of two apparently popular filters.

Big Thanks Martin!!!

martinvicanek wrote:Below are optimized versions of two apparently popular filters.

SVF as I know it, means "state variable filter". What is the difference to the zero delay feedback filter, that also acts as SVF? What's this delay feedback, and what are the pros and cons of both?

Good question. The terminology is not very helpful here: All filters have variable states, regardless of type or order or topology, so "state variable filter" is in no way specific. However, it is normally used to refer to a second order filter with a certain topology that allows fast modulation (as opposed to the widely used direct forms, swhich will shoot off to infinity and interrupt the audio stream if modulated really fast). Zero delay feedback (ZDF) is a very technical term for a faithful digital filter realization of the analog counterpart.
So: the SVF3 is a three times oversampled filter, thereby avoiding the common artifacts near nyquist (peak narrowing and steep falloff). However, the price is a higher CPU load.
The ZDF filter does have the mentioned artifacts, but it is leaner and responds very well to fast modulation.
Note that the SVF3 has a propriatery scaling of the resonance parameter. Take that into account when A_B-testing with the ZDF.

Thank you, Martin!
So, basically they do the same (audio-wise, "they sound the same"), but one avoids artifacts for the cost of higher CPU usage and the other is better suited for fast modulation.

If you allow me one more question: What exactly is a fast modulation? An LFO running at 100 Hz, would that be fast in this context?

tulamide wrote:What exactly is a fast modulation? An LFO running at 100 Hz, would that be fast in this context?

Yes, either that or a sharp envelope attack.