PAiA Custom 4700 Power Supply

The PAiA 4700 uses the 4771 Regulated power supply for modules and and also an unregulated 4770 Watt Block which could be configured for +18V or +/-9V.  Each module has series resistors and 100 F capacitors to further decouple the power supplies.  Series resistor values vary from 100R to 470R.

The customer did not have a power supply and needed a solution.  PAiA modules require very little current but at +/-9V and +18V.  There are no small linear commercial power supplies that supply these voltages and safety with mains wiring is always a concern so I chose to do DC-DC conversion from an external 5V 6A block power supply.

The power requirements for this PAiA system are +18V at 150 mA and +/-9V at 250 mA.  An additional 9V at 150 mA is needed to power a Kenton Pro Solo II MIDI to CV module for the V/Hz conversion of the keyboard which is mounted inside the cabinet.  I used DROK DC-DC converters which provide 300 mA of current at a variable voltage.  Two DROKs are used for +18V and the Kenton Pro Solo II, and a dual DROK is used for +/-9V.  I adjust the DROK outputs for the PAiA to 2V higher and follow them with linear adjustable regulators to filter out switching noise.


I made DC distribution boards and installed MTA connectors on the power supply cables for each module.  I made two distribution boards to minimize module cable length.  I soldered and strain-relieved 22 gauge wires at the distribution boards and the power supply connects with screw terminals.


I made the panel using 1.5mm anodized aluminum with the print graphics feature from FrontPanelExpress.  The anodized aluminum has a matt finish instead of the brushed shiny finish of the original panels.  This module uses a NKK UB26KKW015F-FF illuminated push switch


The switch is rather small and just pushes into the panel.  I wanted red/black 20 AWG wiring since the current is around 4A.  I could only find this in 18 AWG so I added some strain relief for the cables to protect the switch.  I originally used the FPE epoxy studs but the panel is so thin there isn't much holding strength so I drilled the panel and used screws.