PSS-140(1988)

The PSS-140 is a compact, battery-powered PortaSound keyboard from Yamaha, released in 1988 as an affordable home/beginner instrument. It has 37 synth/organ-style mini keys (no touch sensitivity or aftertouch), six-note polyphony, 100 onboard sounds including pianos and real-world sounds plus accompaniments and rhythms, and no pedal inputs. It has a built-in amplifier and speakers and runs on both AC and battery power. ReverbReverb

The character comes from its FM sound chip — the same lineage as classic late-80s/early-90s PC sound cards: the sounds are generated by 2-operator FM from the Yamaha YM2413 OPLL chip and sound similar to the OPL2/OPL3 cards of that era (AdLib and Sound Blaster). It's a great representative collection of what FM does well — organ, bass, synth brass, electric piano, synth strings and melodic percussion — without having to program FM yourself. Underdog GuitarsUnderdog Guitars

A fun quirk that has made it a lo-fi/circuit-bending favorite: the 11-step volume control acts like a bitcrusher — lowering the volume strips bits of resolution, so sounds get grainier and more lo-fi, and the output is fairly noisy at any volume. Underdog Guitars

Specs at a glance:

• Keys: 37 mini keys, no velocity/aftertouch Reverb
• Polyphony: 6 voices Reverb
• Sounds: 100 voices, FM synthesis, with accompaniments/rhythms Reverb
• Sound chip: Yamaha YM2413 (OPLL), 2-operator FM Underdog Guitars
• Power: AC adapter or batteries; built-in speakers and amp Reverb
• Released: 1988 Reverb