AW: Phasers - if you don't have enough already

[Haible Juergen]

	>Maybe I didn't get the magic of your proposal, but it sounds pretty
like
	>state variable filter. Why not using some state var sections?  They
can
	>give all kind of responses and you could use them in parallel or
serial,
	>each with it's own frequency control. I think you need to sum the
hp and 
	>lp output, and you don't even waste gm stages, because it is a 
	>second order ap (I think). Using the other outputs makes a formant
filter e.g.

No magic - just utilizing high quality VCAs with limited output swing
for a general all pass block. Intention is a high quality reissue of the
Variable Slope Filter / Phaser, for example. It's important to have
control of each individual pole (in LP case) or pole / zero pair (in AP
case). 
Adding HP and LP in the SVF gives a Notch Filter (i.e. "2-pole phaser"),
not the mere all pass building block.

JH.