(Not to be confused with E-mu's series of Proteus sample playback synths) A monophonic analog synthesizer produced by PAiA from 1979 to 1982. The voice architecture consisted of two VCOs, a noise source, one LFO, one envelope generator, and a low pass VCF. It had a three-octave keyboard but no pitch or mod wheels. The synth was semi-modular as a patch panel on the rear of the synth provided access to nearly all internal inputs and outputs. And unusually for its time, it included patch memory, with a capacity of 16 patches. An LED adjacent to each parameter knob informed the performer as to whether the parameter's current value was set by a recalled patch or by the knob.
Like all PAiA products, the Proteus 1 was sold in kit form only. It was probably the most complex build of any product that PAiA ever offered, and likely few of the ones sold were ever completed. Only a handful of completed ones are known to exist today.