The Residents

Mentioned in a May 2002 Keyboard magazine article by Hardy Fox.

The Wormwood tour in 1998 included E-mu E4X, Alesis QS6.1, Yamaha DJX, and two DigiTech Vocalists.

Mentioned in a May 2002 Keyboard magazine article by Hardy Fox.

Around 1975, a very expensive ARP Odyssey was purchased. (It was used asrecently as 1997.)

Also mentioned in a post on Fox’s site:

After some serious lobbying on my part, I convinced Cryptic Corporation to part with about $1200 (mid-'70's dollars at that) to purchase an all-in-one device, the ARP Odyssey. I still have it and last recorded with it in 2008. Loser ? Weed, was the first experiment with the device.

Also the subject of this November 2019 article in Tape Op.

Mentioned in a May 2002 Keyboard magazine article by Hardy Fox.

In a May 2002 Keyboard magazine article by Hardy Fox, The Residents are mentioned using the E-MU Proteus MPS plus orchestral synthesizer.

Mentioned in a May 2002 Keyboard magazine article by Hardy Fox.

The Icky Flix tour, in 2001, included Don Buchla's remarkable Marimba Lumina, a Suzuki Q-Chord, E4X, and a T.C. Electronic Voice Prism.

A Mellotron M4000D Mini was one of the two synthesizers used by their keyboard player Erkie (aka Eric Drew Feldman) during their In Between Dreams tour. In this article, which contains several pictures of the tour, one can clearly be seen.

https://sfsonic.com/concerts/the-residents-amaze-the-masses-at-the-chapel/

"[The Residents] had never toured before because their music depended so much on the studio and they feared that it would not translate well to stage. However, the invention of EM-U's Emulator in 1981 was a big step forward in music creation. The Emulator was the first affordable sampler, and it allowed musicians to take all those sounds which can't be produced by conventional instruments and play them back with great precision and control. They were so impressed that, ever the technophiles, they ordered one immediately. Their first one was Emulator #0005. The band used it extensively on the second Mole Trilogy album, The Tunes of Two Cities, and started experimenting with using it to perform music from The Mark of the Mole live in their studio."

As detailed from this page by the Residents themselves.

Mentioned in a May 2002 Keyboard magazine article by Hardy Fox.

Around 1983: Minimoog

Mentioned in a May 2002 Keyboard magazine article by Hardy Fox.

For the Cube-E tour in 1989, they used the Drumkat, Roland D-50, D-10, U-110, D-110, and a Roland sampler, all run with a Mac II and Opcode Vision.

Mentioned in a May 2002 Keyboard magazine article by Hardy Fox.

The Wormwood tour in 1998 included E-mu E4X, Alesis QS6.1, Yamaha DJX, and two DigiTech Vocalists.

Mentioned in a May 2002 Keyboard magazine article by Hardy Fox.

Even as I sit here I think about other keyboards that made minor contributions, including a hot-rodded Casio VL Tone.

Here it is used by the band during the 13th Anniversary Show tour Oslo on October 5th, 1986. It can be seen starting 0:20 and more prominently 2:15.

In a May 2002 article in Keyboard magazine, Hardy Fox mentions The Residents' use of the Roland Jupiter-8 synthesizer.

In a May 2002 Keyboard magazine article by Hardy Fox, The Residents are noted for using the Roland D-50 synthesizer.

Mentioned in a May 2002 Keyboard magazine article by Hardy Fox.

For the Cube-E tour in 1989, they used the Drumkat, Roland D-50, D-10, U-110, D-110, and a Roland sampler, all run with a Mac II and Opcode Vision.

Mentioned in a May 2002 Keyboard magazine article by Hardy Fox.

For the Cube-E tour in 1989, they used the Drumkat, Roland D-50, D-10, U-110, D-110, and a Roland sampler, all run with a Mac II and Opcode Vision.

Mentioned in a May 2002 Keyboard magazine article by Hardy Fox.

The Wormwood tour in 1998 included E-mu E4X, Alesis QS6.1, Yamaha DJX, and two DigiTech Vocalists.

In the documantry The Theory Of Obcurity, Roland Sheehan talks about using a Hammond B3 Organ with the group between 1969 and 1970. Heard on tracks like "Moonman", "I Hear Ya Got Religion" & "The Ballad of Stuffed Trigger"

can clearly be seen at 0:50 in the video

visible at the beginning of the video

can clearly be seen at 0:23 in this trailer