PAiA 4700 Modular Synthesizer System

An example of a PAiA 4700 system. This consists of at least 3 complete 4700 systems plus some extra modules and a bunch of 2700 series modules. A total of 4 double-cases that are hinged and clasp together to form 4 roadcases. The special thing about this system is that all of the modules are working (except where noted), tested, tuned, calibrated and modified to some degree to turn this system in a working musical instrument!

Below are pictures of the actual system and include the modules in each cabinet as well as a not about them if there is something that needs to be mentioned. Here is a list of some of the modifications. Please note that the original integrity of the system has been considered and the modifications are simply enhance what is already there in terms of quality.

The system includes 12 oscilators, 7 multi-mode filters, 10 VCAs, 7 envelope generators, 4 stereo mixers, 2 spring reverbs, 2 12-step sequencers, a compliment of 7 2700 series modules, 4 lfo/noise sources, an 8 channel midi to CV converter (best used in 4-channel cv/gate mode), and some other modules to work with the stock keyboards (untested), and more!

PAiA 4700 Upgrades  
  • all modules tested and calibrated
  • high current regulated linear power supplies
  • comprehensive power supply interface
  • 4x 0-5V regulated bias dual outs
  • 4x 0/5V regulated tune-up section
  • 8x ground buss
  • new 14ga copper power supply buss rails
  • full filter caps every 7 module units (LF and HF)
  • all osc upgraded to 4720-A
  • sequencers: new pushbutton switches
  • all osc 10-turn spectrol tune dial with readout/lock
  • oscillators: saw/square Bennic PP caps 16
  • filters: input/LP/BP/HP Bennic PP caps 20
  • vcas: output Bennic PP caps 6
  • mixers: outs Bennic PP caps 6
  • reverbs: out Bennic PP cap 1
  • mixers: upgraded to 5534 low noise op amps
  • mixer/osc/filter/vca: all signal resistors upgraded to MF
  • envelopes: switches replaced with momentary toggles
  • all pots and switched cleaned

Sound samples are at the end of this page.


With this system you also get a huge collection of original PAiA documentation pictured here (every piece is original). This includes multiple copies of many of the manuals for the 4700 and 2700 line, sales literature, some copies of Polyphony, the 4700 demo book and record, a had written note from PAiA service about a possible DIY repair, some $1 off coupons for modules, manuals for some other PAiA gear. There is at least one manual for all the module types in this collection. Many duplicates and triplicates.


Spare Parts

Also includes are a large compliment of spare parts as well as all the original parts that were replaced with new parts. What to put this back to original? You can! As well you get a pile of 1/8" audio cords and premium single copper stranded Belden rubber insulated pin cables, a bag of about 50 pin connectors and a reel of that Belden wire to make up more connectors. Some extra cabinet rails and original PAiA hardware. Many ICS, resistors, transistors, etc all organized and labeled.

The Complete System

The PAiA 4700 System Details

Power Supply

The power supply cabinet. Includes PAiA midi-CV converter with 8 channels of CV that can be configured in many including 4 channels of CV/Gate. The knobs control the voltage out of the two red jacks under each from 0-9V. under that are 4 power cable connectors that go to the cabinets. Under that are a row of black ground connectors. To the left are 4 connectors and a switch used for tuning. There is a 120V power connector and switch on the back.


Cabinet 4/Left

Top: 2720-3B Band Pass, 2720-3L Low Pass, custom level, 4711 Stereo Mixer, 4712 Reverb with Spring

Bottom: 4770 Watt Block (not connected), 2720-1 VCA, 4730 Multi-Mode VCF, 2720-5 LFO/Noise Source, 4761 Multi:

Cabinet 4/Right

Top: 4710 VCA/Balanced Ring Modulator, 2720-11 Env Follower, 4780 12-Step Sequencer, 4770 Watt Block (not connected)

Bottom: 4761 Multi, 2720-12 Inverter/Buffer, 4780 12-Step Sequencer, 4770 Watt Block (not connected):

Cabinet 3/Left

Top: 4720-A Oscillator,4720-A Oscillator, 4711 Stereo Mixer

Bottom: 4720-A Oscillator,4720-A Oscillator, 2720-5 LFO/Noise Source, 4761 Multi:

Cabinet 3/Right

Top: 4730 Multi-Mode VCF, 4730 Multi-Mode VCF, 4710 VCA/Balanced Ring Modulator, 4710 VCA/Balanced Ring Modulator, 4712 Reverb with Spring

Bottom: 4761 Multi, 4740 ADSR, 2720-4 Function Gen, 8781 QuASH

Notes: second 4730 has noisy output

Cabinet 2/Left

Top: 4720-A Oscillator,4720-A Oscillator, 4711 Stereo Mixer

Bottom: 4720-A Oscillator,4720-A Oscillator, 2720-5 LFO/Noise Source, 4761 Multi

Cabinet 2/Right

Top: 4730 Multi-Mode VCF, 4730 Multi-Mode VCF, 2720-12 Inverter/Buffer, 4710 VCA/Balanced Ring Modulator, 4710 VCA/Balanced Ring Modulator

Bottom: 4761 Multi, 4740 ADSR, 4740 ADSR, 4740 ADSR

Notes: last 4740 always has some attack

Cabinet 1/Left

Top: 4720-A Oscillator,4720-A Oscillator, 4711 Stereo Mixer

Bottom: 4720-A Oscillator,4720-A Oscillator, 2720-5 LFO/Noise Source, 4761 Multi

Notes: bottom left 4720 a driftier than the others, right 4720 PMW range is not working right

Cabinet 1/Right

Top:4730 Multi-Mode VCF, 4730 Multi-Mode VCF, 2720-1 VCA, 4710 VCA/Balanced Ring Modulator, 4710 VCA/Balanced Ring Modulator

Bottom: 4761 Multi, 4740 ADSR, 4740 ADSR, 4740 ADSR

Notes: first 4740 requires a bit of attack to get it going, second 4740 has leds reversed



The system is quite stable although it does drift a bit like all vintage analogue gear. The oscillators have the zero adjust pot accessible from the front panel (stock it is internal and so the module has to be removed to get at it). The pot has also been changed to a 10-turn for finer tuning. The pot is accessed through a small hole to the left of each tuning knob. The tuning pots have been replaced with 10-turn wire wound pots and multi-turn dials. These significantly enhance the ability to fine tune the oscillators. Once set up, the system remains stable with a bit of drift as expected. The multiple outputs of the oscillators are useful for plugging in a chromatic tuner on the fly without disturbing a patch as long as there is one output left open.

The Keyboards

As you can see, the bottom three cabinets are pretty much configured the same way: 4 oscillators, mixer, lfo, couple of filters, a few adsrs and a couple VCAs. The top cabinet is more sequencers and misc. modules. It also comes with two keyboards. Here they are. Please note: the keyboards are totally untested as are the DA and Quash modules. The computer on the one keyboard starts up and will pass the self test.

When all the cases are folded and closed:


Live Show Pictures (that's me in the picsxx)...

The system, before the last 4700 and 2700 modules were added was used in a live show I did. Here are some pictures of that show.



It sounds more like a moog or a CEM based synth, like an SCI Pro One. It doesn't have a thin sound. More of a powerful, rich sound with a bit of grunge. These sounds are straight out of the PAiA VCA's with no EQ or processing, except for the final 'song' which has delay and reverb added.

PLAY Bass sound (heavy) (two osc, LPF, VCA, played via midi-cv converter)

PLAY Bass sound (mellow) (two osc, LPF, VCA, played via midi-cv converter)

PLAY Lead sound (two osc for lead, two for attack sound, each pair through its own filter, played through midi-cv)

PLAY Weird band pass sound (two osc, through bpf, filter modulated via step sequencer, notes sequenced)

PLAY A sequencer sound (two osc, lpf, adsr) sequenced and filter manually manipulated

PLAY This is all the sounds being played live in real time via a Doepfer Schaltwerk. I am playing the lead line live and controlling the sequences live as well. The drums are from a MAM ADX1. Please note that all of this is the system in this auction running at the same time in realtime. There are no overdubs. These are all the sounds from above (using the heavy bass sound, not the mellow one).

Restoration Gallery

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