Introduced in 1982, this hybrid powerhouse ditched patch cords entirely, letting a microprocessor and custom MIDAS software orchestrate six polyphonic voices through digital oscillators and intricate routing— a bold leap toward what we'd now call a DAW in synth form.
At its core, it delivers West Coast synthesis with FM-capable DCOs per voice, feeding into resonant 12dB/oct lowpass filters and culminating in an 8-stage stereo phase shifter for lush, swirling outputs. The original 404A featured capacitive touch plates for expressive play, later expandable via the 406's velocity-sensitive keyboard with polyphonic pressure; both integrate a mod matrix, internal memory for patches, and banana jacks for nine CV inputs, five pulse inputs, ten CV outs, plus clock, gate, and early MIDI/RS232 connectivity. A standout video display brought programming to life, while software-defined controls allowed dynamic reconfiguration of envelopes, sequencing, and timbre.
Around 40 units found homes in studios and institutions through 1985, earning praise for its visionary computer-synth integration and film-scoring prowess, though its steep learning curve and programming demands kept it niche among experimentalists.
