The collection looks to be in good to great condition!
It has a power supply from the 2720 series, so it might be a system pieced together over time rather than one of the packaged systems.
The modules in this system are about the same complement as contained in a 4700J or 4700S and these systems were about the $500 range (kit form, and with more value completed and in good working order); however, it is just a nice monophonic voice and probably most valuable to a collector. With $500 plus in your pocket, there are plenty of other options to consider. The P9700S is about this price, new.
Here's a minimal patch to get sound:
First, the red and black plastic connectors are single-conductor pin or tip jacks (sockets) and plugs for control, etc. and the mini-phone connectors are for the audio signals (these can be single conductor (tip-tip)) within the system, but when going out to an external amp/speaker, mixer, etc, two-conductors are needed (tip-tip (signal) and sleeve-sleeve (ground)).
The keyboard controller and the module cabinet have separate power supplies so the first patch made should be the black pin jack on the keyboard panel to one of the three black pin jacks labelled "Ground" on a cabinet Wing panel.
One more patch from the keyboard to one of the VCOs and you should be able to connect to hear one of the output waveforms -- the pitch control voltage output (graphically represented with varying stepped levels) to the VCO control voltage input.
The other two connectors on the keyboard are for trigger outputs: Gate or Step, and, Pulse, for connection to the Function (Envelope) Generator which makes a control voltage typically for a VCA to frame the audio from a VCO or VCO into a VCF.
A gate-trigger is off (no voltage) when no keys are pressed and on (voltage) when a key is pressed. The pulse-trigger is momentary with the voltage condition for a short duration at the instant a key is pressed.
Go to the PAiA homepage and make the entry
/talk using the 4700
in the Search Site box and you'll see many topics which should help you learn more about the system, in particular, the one with the link to the booklet, Using the 4700S.
I haven't had the chance to post the manual for the 1500 Phlanger yet...
Just connect audio in and audio out. The Pulse or Ramp waves from the VCO sound good flanged.
The pedal is simply a volume pedal with a variable amount of the input available at the output.
Make this entry in the http://www.paia.com
Search Site box to see extras