Optigan Disc Reader

What do you do if you have a bunch of Optigan discs and no Optigan to play them with? Faced with this question I designed a “ghetto” Optigan pickup using an LED and a phototransistor. These are mounted in a focus mechanism from a junk telescope; a slot cut through the tubing allows the device to be positioned over the outer tracks of the disc. The focus mechanism allows the reader to slide from track to track. The output plugs into an ordinary mixer or guitar amp.