Yet another ZDF Ladder Filter

4th order ladder filter /w additional pickups

(15 Votes)
1.2 (Updated 4 years ago)
November 29, 2015
Reaktor 6
Effect Filter


-Bugfix: Forward path and predictive path are now fed through the saturation in the Core Cell filter.
-Request: Test Ensemble has now big sized graphical elements.
-Open: The nonlinear filters can be driven to selfoscillation. But when resonance gets too high (>1.1), unwanted distortion is introduced. The built in filters dont behave like this. So I have to further investigate. But everything is fine while not selfoscillating
-Workaround: Limit Resonance to 1.1.

V1.1 Bugfix
False connection in the Core Cell Filter fixed.

ZDF implementation of a 4th order ladder filter. The test ensemble and the DSP modelling is mainly inpspired by Vadims work and this performance.

I didn't use the ZDF-toolkit, since I worked out these equations some time ago, after I read Vadims book. Now you know why it is called z-transform. :)

The filters in this download consume less CPU, than the built in ZDF ladder filters. But this comes at the cost of less modularity.

This download contents:
- 1 Multimode four-pole ladder Core Cell for use in Primary.
- 1 Multimode four-pole ladder Core Module.
- 3 Ladder LP Core Modules with a modal pickup output. The architecture is mainly compatible to the built in ladder filters, so you may notice a few similarities and also some modules substituted from the built in filters.
- 20 Modal Pickups for the ladder filter, some of them are pretty like the built in pickups for the 4-pole ladder. So these pickups are compatible to the built in 4-pole ladder.


david elson
4 years ago
hey... thanks for your filters... used one here: with a bit extra feedback...
Benjamin Poddig
4 years ago
@ Brett Lavallee: You're absolutely right. The bundle should also be fed through the saturator. fixed in V1.2! Thank you for mentioning. @ Stf Dugs: The range of the cutoff knob, was intented to provide a nicer sweetspot for the modulations. I didnt checked cases, with higher resonancies. Thank you for mentioning that. Limited the resonance to 1.1 in V1.2.
Stf Dugs
4 years ago
Just noticed if the reso doesn't exceed 1 all is fine with high frequencies so never mind my comment!
Stf Dugs
4 years ago
I see you have limited the Cutoff knob to 110,above that frequency the resonance can create some that normal? This limits the high frequency content a little. Thanks.
4 years ago
I think I can tell what the bugfix was, the saturator wasn't hooked up? Is the blue cable still supposed to be unhooked? It looks connected but it's not.
Greg Killmaster
4 years ago
this is great! thank you! If I can make a request for the interface graphics to be a little larger?
Jonathan Canupp
4 years ago
As a filter addict, this pleases me.
4 years ago
Thanks a lot for this, it looks great. Thanks for the Trivial oscillator upload as well, I converted a few of them into blocks already and I like them a lot!