Teisco S100P

Back in 1979, this Japanese-made gem snuck in assignable aftertouch under an ARP Instruments license, a rare trick that let players bend pitches, tweak filters, add vibrato or even unleash a gritty growl just by leaning into the keys—way ahead of its time for a preset monosynth.

Housed in a compact, tank-like body with 37 keys spanning C to C, it packs a single analog VCO feeding a filter with dedicated brilliance control, plus an LFO for modulation. You'll find 32 onboard presets switched via buttons, a pitch-bend slider, octave up/down, portamento/glissando time, and an effects section toggling hold, sustain, note repeat, and that built-in flanger. Spring reverb with level knob adds lush space, while aftertouch sensitivity dial and expression pedal input for volume keep things expressive; high/low outputs and headphone jack make it ready to plug in.

Owners love its punchy, versatile tones that punch above the monophonic weight—brassy leads, growly basses, and weird warbles that hold up in modern mixes. Sure, no patch storage beyond presets and limited tweaking draw some gripes from modular heads, but its playability and that touch response keep it a quirky favorite for hands-on fun.