"Rick Wakeman of the band "Yes" invented and developed this instrument along with help from David Biro. Wakeman formed the company Birotronics, Ltd. which made just 35 Birotrons. Like the Mellotron, the Birotron "sampled" instruments and uses 8-track tapes for the various sounds. This was necessary before digital sampling became available. They were mainly used for strings, choirs, brass, and flutes; sounds not easily reproduced on the synthesizers of that era."
via 8-Track Heaven where you will find more info.
via John Van Eaton
Updates via the comments:
via Darren Landrum:
I seem to recall this one used tape loops, which contained continuous sounds. Shaping could then be added via an envelope generator. Great for sustaining sounds like strings, organ, and choir, but not so good for transient sounds like tubular bells. Of course, the Mellotron was most famous for the sustaining sounds, so maybe the Biro fellow was on to something. The only artist I can recall using the tubular bell tape for the Mellotron is Isao Tomita.
via Milo Johnson:
"The Birotron used 37 8-track tapes, one per key (with all of the attendant problems of 8-tracks) instead of strips of tape like the Mellotron and Chamberlin. Mellotron sounds last about eight seconds and then the tape has to rewind to play the note again. The Birotron used hand-crossfaded recordings to give "infinite" sustain, or at least until the 8-track clicked and changed direction. Rick was the money man and contributed some ideas for improving the instrument, but Dave had already developed it when he approached Rick for financing. It looks like fewer than 20 were ultimately produced and about half of them are accounted for. Dave didn't have one of his own instruments for many years until David Kean of Mellotron.com found and restored one and gave it to him. There is a Yahoo! Birotron Group moderated by Dave Biro, open membership so you can get the story straight from the horse's mouth."
