Phasers (was: Mutron)

[Joachim Verghese]

Thanks to Sean for a nice summary of phaser topologies.

> Any other phaser methods I left out?

I'd like to present an idea that I experimented with some time back.
It's another variation on those op-amp phase shifters -- I use an
NPN/PNP pair for the variable resistance. Actually, it's Moog's
pateneted high-pass filter with the HP stages converted into all-pass.

Works pretty well, but the trannies really need to be matched to
avoid substantial CV feed-through, and with 10 or 12 stages you
ought to provide some sort of thermal coupling as well.

BTW, is there a schemo of the LM3900-based phaser somewhere on the net?

-joachim