via this auction
"In the first enclosure there are two 4770 Watt Block power modules for 8 and 18 VDC, there is a 4740 Envelope Generator, a 4710 Balanced Modulator, a 2720-12 Inverter Buffer and a 2720-11 Envelope Follower.
In the second enclosure there is a 4771 Regulated Power complex power generator with variable voltages and polarities (rare), a 4730 Voltage Controlled Filter, a 4711 Four Into Two Mixer, a 4761 Wing power block, a 4720 Voltage Controlled Oscillator, two 4710 Balanced Modulators and a 4750 Control Oscillator Noise Generator.
There is included also the May 1973 Radio-Electronics article by John Simington (PAiA founder and recently unfortunately passed) titled Build A Modular Electronic Synthesizer wich provides wonderful background and support infos for the line of PAiA synth modules.
Also included are original copies of the documents for the 2720-1 Voltage Controlled Amplifier, 2720-2A Voltage Controlled Oscillator, 2720-3B Voltage Controlled Filter (Band-Pass), 2720-3L Voltage Controlled Filter (Low-Pass), 2720-4 Function Generator, 2720-5 Control Oscilator / Noise Source, 2720-7 Power Supply, 2720-8 Keyboard/Case ( and the assembly diagrams, the 2720-11 Envelope Follower/Trigger, 2720-12 InverterBuffer, and 2720-14 Sine Converter / Pulse Width Modulator. These manuals provide a great amount of context for the 4700 modules and included schematics are basic to the functions they describe. There is also a wealth of information out on the net as you'd expect detailing the internals and functions of these PAiA modules. Check out http://www.synthdiy.com/files/2008/4700ug.pdf which is a User Guide for the 4700/S synth system.
These hip PAiA pieces have come into their own recently as Doepfer, Moog, etc, modules have skyrocketed in price and the vintage analog synth community recognized in the PAiA modules the value engineering and forward thinking design John Simington employed when he created this line of analog treaures.There are a number of great articles about this fine (very underrated, known as "Poor Man''s Buchla" in some hip synth circles) series of vintge synth modules. One article is http://www.johnnypumphandle.com/johnny/Paia/paia.htm, but the most comprehensive is the legendary http://www.musicofplexus.com/paia4700/. In this extensive photo journal essay one can see the scope and depth of the capabilities of these modules when properly handled and with only quite modest upgrades made (High quality caps, ten turn pots on teh VCOs, etc)"
