Eurorack Power Supply

An easy to build Eurorack Power Supply with convenient on-board connectors.

The Build Guide is here.

This is an easy to build bipolar Eurorack Power Supply that outputs a clean, linear source of bipolar +/- 12V for Eurorack Synthesizers. Note that 5V is not provided from this circuit. Max output is 1 amp split between the positive and negative loads. Note that all power supply max loads are "theoretical" so don't try to max out any power supply. Optional heat sinks can be added to help get you closer to the theoretical max output.

This circuit/kit has PCB space for a DC input jack for the wall wart so you don't have to splice the wall wart, and eurorack, Molex (MOTM), and wire outputs on the PCB as well, to allow the supply to work not only as a Eurorack Power Supply powering multiple modules, but as a bench supply as well for testing MOTM and Eurorack DIY builds.

The kit supplies everything except the AC wall wart (easily buyable at Amazon or locally) and an optional output connector (euro or MOTM). The most common use case will be for a user to wire the output (after testing!) to a bus board to power multiple eurorack modules via the output wire pads, but spaces for an Amp 4 Pin (MOTM) and Eurorack connector are present if you want to use it as a bench power supply, or if you are using a 4pin connector rout power to bus boards.

Note that while the kit supplies LM78 and LM79 regulators selected for +/- 12V systems, using a different wall wart and different LM voltage regulators will allow for +/- 9 or 15 volt systems.

You must supply your own wall wart which outputs 12 to 15 VAC at 500 to 1000 mA. The output of the wall wart MUST be AC. This wall wart is a good example.

This should not be a first builders kit as it contains mostly polarized parts, and getting it wrong may result in fire and/or destruction of other Eurorack modules. While the kit is not hard to build and has a low parts count, careful attention is needed throughout the build process to ensure no mistakes are made.

The circuit is very simple: A bipolar AC power signal comes in, is rectified into positive and negative power by diodes, and then regulated to 12V on either side. The 2.4K resistors provides a load to ensure the circuit works even with no modules to draw current, and the large caps are there to clean up the power signals. The smaller caps and extra diodes are just there for safety.

I am not responsible for any harm that comes from building, installing, or using this power supply. Build and use at your own risk!