He used a phase shifter in '72. I have heard it was a Maestro Phase Shifter, but I don't know for sure. He started using it in the fall or late summer. When I heard them at Stanley Theatre in Jersey City (9-28-72), he used it on alot of the slower songs.
I first became aware of his early phase use on Spring '73 recordings, checkout any Here Comes Sunshine as an example. I believe the phaseunit he used in '73 and '74 was an Orban. The Eventide delay was a Clockworks 1745. Now I'll have to do some homework with some late '72 stuff... poor me!
"There, in huge black letters, was 'The Grateful Dead'. It just... cancelled my mind out."-Garcia