Synth: Sequential Circuits Pro-One
Review by: Tim Walters

Summary: Versatile monophonic mini-synth.  Excellent bang for the buck.

Years Made: 80-81 (?)
Polyphony: mono
Multitimbrality: nope
MIDI: nope
    Note on/off:
    MIDI controllers (aftertouch, CC, etc):
    Sysex patch dumping:
    Sysex parameter control:
Other external control: 
    CV/Gate: yes
    Clock: yes
    Other CV: filter
    Audio input: yes, with gate to trigger envelopes
    Proprietary (DCB, etc): nope
    Programmer: nope
Patch storage: nope
    Patch dumping (tape, MIDI, etc):
Voice architecture:  
    VCO A saw/pulse (either or both), syncable to VCO B, hardwired to kybd
    VCO B saw/tri/pulse (any or all), lfo/normal, kybd on/off
    Noise (somewhere between pink and white)/external input
    1 LFO (saw/tri/pulse (any or all))
    VCF (cutoff, res, ADSR env amt, kbd amt)
    VCA (ADSR env)
    2 modulation busses (direct/mod wheel)
    Mod sources:  filter envelope, VCO B, LFO
    Mod destinations:  VCO A freq, VCO A pw, VCO B freq, VCO B pw, filter
Sequencer/Arpeggiator: 
    40-note dual sequencer, volatile
    Latchable up or up/down arpeggiator
Keyboard/rack: keyboard only
Known problems: none
Accessories: none that I know of
Related synths/gear: Prophet 5 -- manual says Pro-One is identical to one 
    Prophet 5 voice
Price range: $100-$350 (I've seen both)
Availability: common
Comments:  A lot like a MiniMoog with one less oscillator.
    Strengths:  Good modulations, oscillator sync and external input make
	this an extremely versatile synth for the price.  Easy to work on--
	it's easy to open, the layout is clear, the technical manual is 
	well-written.  I like the sound but haven't heard enough of the 
	classics to really compare it in-depth to them.  It's very light and 
	portable, as well.  Weaknesses:  No HPF, only one flavor of noise, 
	LFO inseparable from arp/seq clock unless you have external clock 
	source (or use gate from external audio).
    Overall:  Excellent price/performance ratio.
    Other:



Tim Walters 
Demiurge
Core Dump Records
walters@digidesign.com or walters@mills.edu