A step filter with configurable steps would be a great addition. Looking at the stompbox DSP-DNA as one giant algorithm, it certainly seems possible. What makes the ADR III unique is the step sequencer routing & control modulation capabilities. The sequencer + A/D envelopes can be routed to filter, amplitude, & ‘pitch’ (tuned resonant filters). But – unless you’re dialing in the USR pattern – you’re still selecting among 20 fixed patterns.
The HarPeggiator has two parallel sequences. We’ll leave out the pitch, fuzz, glitch, and combi-FX for now. Each one is limited to five fixed filter sequences (plus random). There are 20 fixed envelopes (plus OFF); one selection applies across all steps. There are 20 ‘Rhythm’ patterns (plus random), for independent control over amplitude. If you approach the HarPeggiator as a multi-effect, some of the same can be approximated, with a little work.
I particularly favor the RND filter mode; especially preceded by some distortion for the filters to ‘chew on’. It’s deeper, more controllable, and a lot less expensive than a vintage Oberheim VCF-200. The 5 fixed sequences can also be useful, considering that two sequences can be audibly combined, but set up with different configs.
Some multi-modulation effects – similar to the ADR III – are possible in other algorithms. The idea here is to layer the LFOs on top each other. One acts as the ‘step’, with the 2nd LFO providing the overall step sequence ‘shape’.
