Power Supply For Korg Volca

For the last post of 2018, I wanted to write about the making of a small power supply for 4 Korg Volca.

Power supply inside

A Korg Volca can be powered by batteries or by a dedicated power supply : the Korg KA-350.  Not only is that power supply expensive compared to the affordable Volca, but it is over-dimensioned and you end up using one per box.
Moreover, Korg uses a slightly different connector than most 9V guitar pedals power supplies and the polarity is reversed (positive inside).  They correspond to the EIAJ-02 japanese standard.  Size is 4.0 x 1.7mm.

Power plug assembly in progress

There are some solutions out there, like alternative power supplies, adapters, daisy chain cables, etc.  Nevertheless, I couldn't resist to make my own power supply.

Bob screws the cables

This is a classical dual regulated power supply.    I used a design from the excellent Sonelec website.  You'll find the layout below.

The transformer is a 220V to 2x 12V transformer.  Bridge rectifiers are DB205.  Regulators are LM317.  The power plugs are PP-014 from CUI.  The enclosure is a 137x97x67mm ABS Polycarbonate Power Supply Case.

Splices

I bought the 5 connectors from Mouser and the plastic enclosure from Banzai Music.  All the other parts are leftovers from previous projects : I usually buy a little more each time to cover losses, destruction or to simply fill my drawers just in case...

Each one of the two outputs of the power supply is split in two with splices and a bit of heat shrink tube.

The transformer is only rated for 12 VA, which means 500 mA per output.  Volca are reported to draw about 80mA. This means a total of 160 mA per output.  That's enough safety margin for me.



That's it.  Let the fun begins.

Circuit and layout