In the article it states : "In the studio, David likes to tinker around and get his sound as quickly and as easily as possible. He plugs into a Boss CS-2 compressor, a T.C. 2290 for delay and a Yamaha SPX90 for stereo chorus. Then it's into a Gallien-Krueger 250Ml amplifier at an overdriven setting into a Fender Super Tube amp at a clean setting."

As part of his 1988 Soldano/Cornish Guitar Routing System, Eric Clapton used the Furman PL-8 Power Conditioner and Light Module, a SAMSON UR-5D UHF wireless receiver, a SAMSON BR-3 VHF receiver, a Drawmer 1960 tube compressor, a YAMAHA SPX-90 multi-effect processor, a Dyno-My-Piano CS-5 Tri-Stereo Chorus, a TC Electronics 2290 dynamic digital delay, a DYNACORD CLS 222 Leslie simulator, a YAMAHA GEP 50 multi-effect processor, a Roland SDE-3000 digital delay as well as the TC1210 spatial expander with VHS/UHF aerial unit at rear.

the Yamaha SPX90 Multi-Effects Processor is listed in this blog

July 5th, 1986: Johnny's rack for Euro Tube contained a Yamaha GC2020B on top with a Yamaha SPX90 below it.

For the 1988 David Lee Roth and 1990 Whitesnake world tours, Vai used one of these multi-effects units as part of his offstage effects rack.

Used on the PopMart, as specified by tech Dallas Schoo in this September 1997 Guitar World interview titled "Closer to The Edge".

One irreplaceable effect is the Edge's Korg SDD-3000 digital delay. "That's one of his favorites because it has so much warmth," says Schoo. "Most of the albums were made with that delay." Other processors in the Edge's rack include a Roland SDE-3000 digital delay and Yamaha SPX90, Kolrg A3, Rocktron Repliflex, DigiTech 2112 and Eventide H3000 multi-effectors. He also carries a full array of pedals, indluding a Dunlop Fuzz Face, Dunlop and Bradshaw multiple-wah systems, several Boss distortion units, an Electro-Harmonix Big Muff, and Lovetone's Big Cheese distortion, Doppelganger phaser and Meatball envelope follower.

Zakk Wylde utilized the Yamaha SPX90 Digital Multi Effects Processor in recording the albums No Rest for the Wicked and No More Tears. A video by Michael Nielsen demonstrates the processor's sound, closely resembling the tones on these albums. An image on Pinterest further associates Zakk Wylde with the SPX90.

"If I ever had a secret weapon it's the Alesis and the [Yamaha] SPX 90 and again, it's the reverse reverb program."

Lots #8, #9 and #10 in the second group (#3198) of Julien's Auctions' December 17, 2017 "Neil Young Online Auction".

Lot 8

A rackmount Yamaha SPX90 reverb, serial number 45292, marked with tape "Aux. #1."

19 by 10 1/2 by 2 inches

Lot 9

A rackmount Yamaha SPX90 reverb, serial number 43141.

19 by 10 1/2 by 2 inches

Lot 10

A rackmount Yamaha SPX90 reverb, serial number 26232.

19 by 10 1/2 by 2 inches

In this article in the December 1995 issue of Future Music magazine, the SPX90 is named in the "Kit List" as being one of Eno's effects.

Mentioned and shown in this Gear Run at 0:44

Jeff used a Yamaha SPX90, according to Guitar Geek's rig diagram, of his 2002 rig.