Lots go crazy: An Oberheim OB-8 synth from the Purple Rain sessions and the Amek mixing board that Prince used to record Dirty Mind in his home studio are both up for auction

Prince is synonymous with Oberheim - he used them on multiple albums throughout his career. One of those in question was an OB-8 owned by Matt 'Dr' Fink, keyboard player with Prince's backing band The Revolution. This featured on Purple Rain, Around The World In A Day, Parade and Sign o' The Times, and it's about to go under the hammer.

The OB-8 that's being sold comes from Fink's personal collection and, as well as being used in the studio, it was also employed as a backup synth on tour. It's expected to sell for between $62,500 and $125,000.

The OB-8 was the final model in the OB range, succeeding the OB-X and OB-Xa , which Prince also used. You can hear these synths' sounds all over the Purple Rain album in particular, including on Let's Go Crazy, I Would Die 4 U and Baby I'm a Star.

Fink's OB-8 is being sold by Propstore, and the suggestion is that Prince himself would also have played it from time to time.

It's not the only item from the doctor's musical/medical bag that's up for grabs, either: there's also an Amek mixing desk that was used to record the Dirty Mind album at Prince's home studio on the North Arm of Lake Minnetonka, Minnesota.

"Prince used this mixing board to record and track raw recordings and create rough mixes for songs on Dirty Mind," says the listing. "These rough recordings would then be mixed into a final version, usually on a board in Hollywood Sound Recorders studio in Los Angeles."

Discussing his working relationship with Prince at that time, Fink told Propstore that this was "when I managed to impress him with something I had written, musically. He just said, 'hey, I'd like to write something against that,' and that was the Dirty Mind music, which he put lyrics and melody to. That was in 1980, I believe, and we recorded that song, amongst many others, on that board that's up for auction, the Amek board."

The board was also used during the early stages of the subsequent Controversy album, before Prince retired it when he moved to his new Kiowa Trail home studio to finish the record. This is when it came into Fink's possession; it's said that band members were known for asking Prince for permission to take bits of his gear after he'd finished using them, and that's what happened here.

The Amek board could sell for between $37,500 and $75,000, says Propstore.