• Sale
  • $ 40

Erthenvar Freelunch Efficient -12V to +5V Eurorack regulator provides your modular system with up to 600mA of current on the +5V rail without loading down the +12V rail.



The standard Eurorack bus header was designed with a total of 16 pins and includes a +5V rail. Unfortunately, the Eurorack standard does not require this rail to be powered because traditionally few modules have needed +5V in addition to +/-12V.

Some of the latest offerings in the Eurorack format use digital technology to bring new and exciting circuits to the market. Modern digital integrated circuits require +5V (and lower) voltage supplies. Currently, manufacturers using digital ICs are forced to include onboard regulation from +12V to +5V, which can overload the +12V power rail.


The Freelunch -12V to +5V Eurorack Regulator will breathe new life into your existing case and power supply by powering the +5V rail of your bus board without loading your +12V power supply. Most modules draw more from the +12V rail than the -12V rail, leaving the -12V as an untapped resource in your existing power setup! The Freelunch provides up to 600mA of +5V power to the on-board Eurorack bus headers and optionally back to the bus board.




  • High efficiency -12V to +5V inverting voltage regulator
  • No load on the +12V power rail
  • Pi filters on the input and output
  • New: Header guard ensures proper installation
  • Two standard 16 pin Eurorack bus headers that include +5V from the Freelunch module and direct connections to other bus pins
  • Indicator LED shows if voltage is present on +5V bus power rail
  • Jumper routes regulated +5V back to the bus board (only install if LED is NOT active)




  1. Turn off case power supply
  2. Place the Freelunch on to an open 16 pin Eurorack bus connector. The Erthenvar logo should be rotated 90 degrees clockwise and the silkscreened -12V designation should match your bus board -12V location (usually at the bottom). The header guard will prevent you from fully inserting the Freelunch unless all header pins are properly aligned
  3. Ensure the jumper is not installed, then turn on case
  4. (Optional) if the indicator LED is not active when the case is powered on, the jumper can be installed on to the header to power the bus board with the +5V output voltage from the Freelunch. The indicator LED will activate after installing the jumper. DO NOT install the jumper if the LED is active