sampleRateReduction + new SVF filter = self-oscillation

[chrisbc]

Tested with community build on 7SEG https://github.com/SynthstromAudible/DelugeFirmware/actions/runs/5478105923

Steps to reproduce

• SHIFT+NEW = new song (defaults to new CLIP)
• select KIT (default KIT 0)
• add a few beats - e.g. KIK, SNA, KIK , SNA
• hit PLAY
• select AFFECT-ENTIRE
• dial in a little SAMPLE-REDUCTION (CUSTOM-1), 1 bar is enough
• select CUTOFF/FM
• now, mind your ears, press-click lower GOLD encoder twice (to engage SVF) and we have immediate self-oscillation.

At this point the SVF filter is in default with MIN resonance and MAX cut-off,
NB: the feedback can be killed by either:

• setting sample-reduction off
• lowering the freq on SVF filter

This may be relevant to #105

[m-m-adams]

Confirmed and working on a fix