One of my still prized possesions is the Yamaha PSS480 that still sits in the music room here alongside of several modern and high end synths and workstations. It makes for a great cheap sounding FM synth module.

I sometimes wish I hadn't sold the various Casio and Yamaha home keyboards I had from the 80's and early 90's, as they would have made for some cool circuit bending projects. My PSS480 remains intact btw, but if I ever find aother one.... In fact, I recently started looking for these types of boards at yard sales and the local thrift shops. I'd also love to run into the old Concertmate and Radio Shack offerings, some of which were made by Moog and / or had the same filters.

Short of that, some of the VST emulations of the old school cheapo synths have given me hours of playing pleasure.

Z