Oakley Rack Power Supply Unit - RPSU

Constructional difficulty: Easy

A completed RPSU board fitted into an Oakley SRE330 rack ensemble module - the optional power on LED parts have not been fitted here.

The Oakley Rack Power Supply Unit (RPSU) is a split rail power supply design that has been designed to power our SRE330 rack module and other projects. It will supply a well regulated +/-15V although it can be simply altered to supply any split rail voltage from 5V to 20V. The amount of current that the unit can deliver is dependant on the AC power source, the choice of smoothing capacitors and the heatsink used. It is expected that the RPSU be fitted into a metal case and the case used as a heatsink for the two power devices.

For safety reasons it is suggested that the unit will be used with an external single phase wall-wart (plug top adapter) or centre-tapped linelump (in line mains adapter) such as the Yamaha PA-20. This ensures that all high and dangerous voltages are kept out of your module's enclosure.

It is possible to use a standard transformer with the RPSU. But note, a component level mains transformer should only be used if you know how to connect high voltage wiring. On no account should this project be powered by a component level mains transformer if you are not familiar with fusing, earthing and safe connection of high voltage equipment. For safety reasons Oakley Sound can only endorse using this module with a low voltage input from a suitable plug top or inline power supply.

The power supply uses standard parts throughout and requires only a simple voltmeter to test. The circuit board takes less than an hour to build.

Various options are available for different types of switching, earthing and power on indication. The strong glass fibre PCB is silkscreened for easy component identification. It uses generous pad sizes, through plated holes for easy soldering and wide double sided copper tracks for reliable operation.

The unit features two 0.156" headers for the outputs. PS1 can be either four (or five) way and carries +15V, 0V, 0V, -15V, (ground). PS2 is a three way header and carries +15V, 0V, 0V. PS1 when fitted with a four way header is MOTM compatible.

The board size is 150mm (width) x 50mm (depth).


RPSU issue 2.1 PCB .................................................... 12GBP Temporarily out of stock. More boards should be available in February 2023.

3-pin power socket for external PSU ............................. 2.50GBP

All of the other parts should be able to be purchased from you usual electronic component supplier. Please see the Builder's Guide for more details.

See the Oakley Sound ordering page for ordering information, shipping charges and payment methods.

All prices include VAT at UK rates. Shipping/postage is additional to these prices. See also the FAQ page.

The three pin power socket for use with external PA-20 and PA-30 power supplies.


Builder's Guide

Construction Guide Our handy guide to building Oakley DIY projects

Parts Guide Our handy guide to buying parts for Oakley DIY projects.

Use 'save as...' button to download and view the files.

The schematic is provided only to purchasers of the printed circuit board. This will be sent to you as a PDF file with your shipping confirmation e-mail.

For technical support on all Oakley projects please refer to the knowledgeable and helpful Oakley Sound Forum which is hosted at ModWiggler.com. Tony Allgood does not provide official building support for Oakley projects, but he and many others are usually available for help via the forum.

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Copyright: Tony Allgood
Last revised: November 18, 2022.