I think he favored these units in the early 80's. Here is a post I found on this forum:
This is taken from Dozin's post at http://dozin.com/bobs/rig.html
According to John Cutler, design engineer for the Grateful Dead, the signal from Bob's Ibanez goes into an IVP preamp. On that particular preamp there are two effects loops available; one is after the preamp and before the equalization, and the other is post-equalization and before the master gain. Cutler has built a switching system that uses a logic-controlled relay to insert or delete what-ever effect is not in the signal path when not in use; it's hardwired bypassed.
In the first loop Bob uses a Furman reverb and Ibanez UE-400 that contains a compressor, a chorus, a flanger and a distortion box. In the second loop he uses an Ashley Compressor and an Ibanez AD-230 delay and flanger unit. Bob also uses a Cutler-built custom pedal that remotely controls the electronics on the rack and is a combination phase and wah-wah. He can have it either phasing,wahing, or a mix of the two. When he move the pedal from back to forward, both the wah and phaser go up in tone. Most phasers use an oscillator that sweeps back and forth, but this replaces the oscillator with a footpedal. The rack also contains a Furman parametric equalizer that he primarily used when doing both electric and acoustic sets on the same night. He plugs his Ovation into the Furman.
Weir's 1000-watts-per-channel power amp is no longer available. It was called Godzilla and was made by Great American Sound (GAS amp) which has since folded. Cutler reports that they only made about 20 or 30 of them as prototypes and never went into production. He plays through eight 10" Gauss speakers in a Hard Trucker's cabinet. Although, Bob's speaker configuration changed all the time.