via this auction
"extraordinary Mid-70's vintage analog VCO/VCF/VCA synthesizer under digital control is an unusually expressive instrument as it features immediately accessible, simultaneously-available aftertouch or "Touch Sensor" (aka presssure sensitity) MULTIPLE parameters.
EXPRESSIVENESS! TOUCH / AFTERTOUCH / PRESSURE EFFECTS! Sure, others have Pitch Bend, but here you have, at the flick of a single switch which is ideal for performance (thus the PRO moniker): "WOW" (res filter opening/closing), "GROWL" (LFO LF Mod), BRILLANCE, VOLUME, and of course, VIBRATO.
OVERALL TOUCH SENSITIVITY immediately accessible. GLIDE / GLISSANDO / PORTAMENTO also immediately available via included AUTHENTIC ORIGINAL ARP FOOTSWITCH, with immediately available GLIDE SPEED Control too! REPEAT effect, with it's own LFO also available, instantly.
The ANALOG VCO/VCF/VCA voices are further enhanced with digitally-routing control through thoughtful fixed format resonant filter banks, and a HP filter, so there are actually SEVERAL seried filters. The sounds are primarily LEAD sounds, as this is a solo, monophonic instrument. Add a little chorusing or delay effect externally for even richer "phatt" sounds.
THREE Octave manual uses easily accessible simple contacts for easy user maintenance.
INCLUDED: FULL ARP SERVICE MANUAL, ARP PORTAMENTO FOOTSWITCH
The design is particularly ripe for modification, and bringing out some of the analog controls over the VCO/VCF/VCA. We've chosen to keep the design and circuitry intact per collector's usual preference. If you are interested in having this already-incredible Lead Synthesizer tricked out (modified) by us, please inquire, OR we can assist you in doing yourself, but be forewarned, mid-70's circuits have their own peculiar idiosyncracies and exotic parts requirements for compatibility.
HERE are two photos showing all the voices. I believe the RED voices are based on pulse and/or square waves with even harmonic content in varying ratios and the GREEN are based on sawtooth or highly filtered (sine or triangle wave-like haunting sounds). Remember, this is a LEAD INSTRUMENT - monophonic, no chords. All the power is packed in AVAILABLE EXPRESSIVENESS. Take some time to learn the extensive expressiveness parameters available on this amazing synth and you will create incredibly organic, heartfelt, powerful sounds."
