A board to take the input of two single-output 15v SMPS AC-DC PSUs and output a precise, regulated +/-12v DC to use in a Eurorack system.

Using two 15v single-supply SMPSs**, the board combines the negative output of one supply with the positive output of the other supply, forming a reference ground. The remaining positive output provides +15v to the board's negative rail and the remaining negative output provides -15v to the board's negative rail. The positive and negative rails are then filtered before being regulated by a LM350 on the positive rail and an LM337 on the negative rail. The two regulators can be adjusted using a trimmer to achieve exactly +/-12v DC at (depending on the heatsink and supply chosen) up to 2A** on the positive rail and 1.5A on the negative. This is roughly enough power for a 9U 104HP case.

The boards use blade/faston terminals to distribute power to the busboards.

Wiring for the board is as follows:

An example of usage is as follows:

There is no 5v regulator or rail provided due to its huge decline in usage. If needed, please either use a busboard with a 5v regulator or a solution such as the Mutable Instruments Volts plug-in module.

** Common examples are the Mean Well RS-35-15, RS-50-15 or the smaller LRS-35-15 / LRS-50-15 (or similarly specced)

*** Theoretically it could provide up to 3A, but you would need a very large heatsink with active cooling.

Project is CC BY-NC-SA 4.0