See for instance the Mellotron, or this relatively easy DIY alternative, [Rich Bernett]’s Cassettone cassette player synth. The Cassettone works by substituting the trim pot that controls the ...

Bulky, heavy, ugly and decidedly unsexy to look at it might have been (especially the early models), but the Mellotron carved out its own niche in the progressive rock scene in the late 60s and ...