Updated version available!

What's new:

• A completely new layout.
• Addition of two LEDs.

AC/AC adapters sources

• https://www.dreadbox-fx.com/product/psu-12vac/
• AC to AC Wall Adapter Transformer 12 Volt @ 1000mA

What is the Mini Dual Power Supply?

The MDPS is a small linear Power Supply, perfect for powering a small Synthesizer, with just a simple AC adapter. It is able to deliver a Bipolar (or "Dual") output voltage: both positive and negative voltages (+12V and -12V for example).

It's a good choice for your small Eurorack skiff or your MFOS SoundLab MiniSynth for example. It's also a good fit for an op-amp project that needs a dual and symetrical power supply.

For your Eurorack synth, please have a look to the "Eurorack compact power bus".

The MDPS is designed for small current needs. The maximum available current depends on the AC adapter, but do not expect more than 100~200mA per rail.

If you need more power, please consider a different solution: The Eurorack Power Supply for example can deliver up to 1.25A per rail!

In details

The max output current will depend on several factors. But consider carefully that this power supply is unable to provide more than 500 mA. The reason why you cannot draw a huge amount of current is due to the design's topology. It is built around a double half-wave rectifier. It means that only half of the input AC waveform is kept on each rail. The missing half waveform is compensated by their respective reservoir capacitor (C1 and C6). As capacitors cannot deliver more current than they can, there are chances that some ripple occur at the output. To be safe, use this power supply in low power systems only.

Do not use DC Wall Wart. Use only AC output plug pack.

Input type: 2.1mm Barrel Jack. There is no input polarity.

What's included?

For the PCB Only: Well... it's PCB only! However, components are standards and easy to find.

For the Kit version: One PCB and the components on the pictures are provided. Nothing less, nothing more. You have to build it yourself (it's DIY!). No heat sink provided.

For the fully assembled version: A complete and tested module, with all components soldered. No heat sink provided.

Choose your Output Voltage

Several options are available. +9V / -9V is a good choice for numbers of small projects and guitar effects, including some MFOS products. +12V / -12V is what you need for any Eurorack Modular Synth module. Be careful: some modules also need a separate +5V rail and it's not available with this power supply.

Check my blog! Updates, tips, building guides, more products!

More information: http://www.davidhaillant.com/category/electronic-projects/power-supplies/mini-dual-power-supply/

Layout and size:

Schematic:

More pictures