6 dB/octave filter unit

[olofson]

6 dB/octave state variable filters are very low cost, and still quite useful for tweaking the timbre a bit - like a very cheap EQ.

It should have per-band gain controls instead of the typical filter type selector, similar to how filter12 works, to make it usable as an actual EQ. (A traditional filter needs additional units and manual wiring to do that.)