Prince played Hohner Madcat and Dave Rusan Cloud guitars. Keyboards include a Yamaha DX7, a Fairlight CMI, an Oberheim OB-8, and an Ensoniq Mirage. The main drum machines were a Linn LM-1 and the Fairlight. Guitars and the Linn were all processed through Boss effects.
You can find a full list on the Sign O The Times era page.
Sign O The Times is Prince's ninth album. It is one his most critically acclaimed records and produced three top ten singles. It features a mixture of styles, including pop, funk, dance, rock and jazz.
Compared to previous albums, it features a stripped back sound, featuring distorted guitars, the Linn LM-1 and digital keyboards like the Fairlight and the Sequential Prophet VS.
Prince toured Sign O The Times from May to June 1987 with a new, unnamed band. Prince also filmed a concert movie with this band in Europe and Paisley Park.
The Black Album was recorded around the same time as Sign O The Times so is included on this page. It was released as Prince's sixteenth album in 1994.