Maxx PS1-1A 4 stage 136OO phaser

[tomg]

The PS1-1A Phase Shifter is based on the Small Stone. It has four OTA
sections ,is designed to run from a dual power supply, can be controlled
by standard CV or it's internal lfo and has rate range color and cutoff 
controls. The lfo can be a tri, square or switched out.

The PS1 does most of the Small/Bad Stone stuff and at 
times has that Bi-Phase sound but not quite approaching the jet take 
off res the BP is famous for. I think it needs another 2 OTA sections 
and I think I can do better,but that will have to wait for the effects
section.

Over the weekend I thought I would throw a small four fet phaser together
to kick off the effects section but one thing leading to the other I had
those 136OOs laying out on the bench. The PS1 is built out of two LM136OO
and one TLO74. 

Modifications from the original.

Changed the input amp from a dual transistor to a op-amp
Changed the bias to run from split supplys +-12 to +-15.
Added a fet buffer to the output.
Changed the lfo to my standard thing. 
Added a external CV input.
Added op-amp in feedback loop for adjustable color.

pcb soon....

The Page

http://www.tomg.vivid.net/maxx/page_038.html

The sample is me smackin' my guitar arround..679K

http://www.tomg.vivid.net/maxx/pics/ps1.wav