Mutron

[R.G. Keen]

>Any other phaser methods I left out?  I left out some of the ones I really
>don't understand, like the Hammond vibrato.  How about the Magnatone amps -
>did their vibrato use phase shift stages?
The Magnatone is a phase splitter phase shifter, like the Univibe, just implemented
with tubes for the splitter and varistors for the variable resistors. The complexity
you see in the Magnatone schematics is an artifact of having to use split-phase
LFO drive to the varistors to cancel out the many-volts of LFO to get the 
varistors to change resistance. 

I have a working version of an all-tube univibe that has been on ice since last
year when I got drafted for a fire-hose job. It's still waiting to get put in 
a complete enclosure, but there hasn't been time to even do that.