via this eBay listing
"Vintage PAiA 4700 Series Modular Analog Synthesizer with Keyboard – Needs RepairOffered here is a PAiA 4700 Series Modular Synthesizer, produced between the early 1970s and early 1980s. This system is being sold as-is and will require service to be fully operational.
Functional Status
VCO 1: Powered and producing signal. Can be patched through the filter and mixer and triggered via the keyboard.
VCO 2 & VCO 3: Not producing output. Both modules are not connected to power or ground.
Sequencer (4780): Does not power on or respond. The power and ground wires are present on the bus but not connected to the sequencer module.
Filter (4730): Produces sound when triggered through the mixer.
Keyboard / Pitch Tracking: Synth triggers properly, but pitch does not track consistently across notes within the same octave and will require calibration or service.
Internal Condition
Power and ground wiring for the sequencer, VCO 2, and VCO 3 are disconnected internally.
Loose wire ends have been insulated.
Reason for the disconnections is unknown.
Included Modules
4720 VCO (x3 total)
4730 VCF
4740 Envelope Generator (x2)
4710 Balanced Modulator (x2)
4711 4/2 Mixer
4712 Reverb
4770 Watt Block (x3)
Control Oscillator
4761 Wing
4780 Sequencer
Notes
No patch cables included
Vintage condition with cosmetic wear consistent with age
Not fully functional and sold as-is for restoration, repair, or knowledgeable users
The PAiA 4700 is a historically interesting DIY-era modular synthesizer with a distinctive analog character. This example will appeal most to technicians, restorers, or modular enthusiasts comfortable with vintage electronics."
