Teisco SX-400

Back in the early '80s, this synth punched way above its budget weight class by packing four independent analog oscillators into a keyboard instrument that could go from polite polyphony to monstrous mono leads, all while offering memory storage that was pretty forward-thinking for the era.

At its core, it delivers four voices through independently tunable VCOs, each with multiple waveforms like sawtooth, ramp, square, and triangle, routed through a shared filter and a single envelope generator for the VCF, plus another EG for the VCA. You'll find a swarm of sliders for hands-on control over everything from LFO modulation—two of them, one with delay and shape options—to cutoff, resonance, and amplitude, with aftertouch and a pitch/mod wheel that can simultaneously bend pitch, vibrato, and filter sweep. The 32-key dynamic keyboard feels responsive, and modes let you switch between quad poly, dual, or single-oscillator mono mayhem. It's a hefty desktop beast with stereo outputs for its built-in Ensemble chorus, pro-level +4dBm option, and 8 factory plus 8 user patches stored in internal memory.

Players have long praised its thick, warm analog tone—often stacking those VCOs for Juno-like depth with more expressive control—and the hands-on slider layout that invites tweaking, though some note its large footprint demands serious desk space.