MOTM

> As John described, it would be nice to have the functionality of 2 420's
> (I opt out here since I don't have a 420 but do have an MS20, and
> another part of my reluctance to purchase a 420 is that I've not found
> notch filters all that useful).

Two 420's make sense - that's the MS-20 configuration, when the first is
in HP and the 2nd is in LP mode.
Two filters in series in *Notch* mode emulate a 4-stage phaser. With
a single filter (one notch) the effect is too weak for being recognized
as phaser, but from notches upward you should get a reasonable
phasing effect. (Set Frequency 1 or 2 octaves apart, and modulate
with the same CV.)

JH.