USB Power supply module?

I’d like to build a module just for powering my peripherals (keystep, beatstep pro or charging my phone). Anyone know much about diy usb supplies or know of a good premade circuit for it?

I’m guessing that plans will be hard to come by as it’s one of those things that most people don’t do themselves since it’s harder and more expensive to find the separate parts than it is to find a full working one when you stop for gas or a burrito for less money than the gas or burrito, but if anyone has a DIY one, it’s going to be in this forum!


a lot of power strips come with USB on them and you can find them pretty cheap


The 1st thing that comes to mind is a USB power supply. However, if you look at videos like this one:

or this one,

and the list BigClive has investigated goes on,

you’d be surprised how dodgy some of these are. Some are even dangerous.
You can find more videos where USB-power supplies are tested.

Most are switched mode power supplies (that do not have a mains transformer) and do not have a decent separation between the high voltage input stage and the low voltage output stage. Not to speak of the HF-distortion that might seep into your audio circuitry.

So I’d advice to build an old fashioned transformer based transistor or LM7805 regulated DC power supply to be on the safe side. Yes they run hot, yes they are inefficient, but they are electrically safe and do not introduce HF noise.

If you still want to got the USB-power supply route, it could be wise to look at a few videos and find a power supply that is a good one (won’t be easy).


I had the bright idea of getting USB from the 5v rail that I don’t use in my Eurorack system, especially since at least two such modules exist, but they turned out to be noisy as hell. Hadn’t thought of going the linear 7805 route. In particular, I’d like my Roland Boutiques to be less noisy.

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I use these. I know they are not DIY, but they’re crazy versatile and you can connect various ones together in whatever configuration you want.


Maybe just mount a powered USB hub or charger behind a modular front panel.

This car one looks kinda cool and only requires a 12V power input.

This USB hub is designed for a PC front panel, but should work with just +5V and +12V supply (might need more 5V power than a typical modular synth power supply provides though).

Or if you don’t want to siphon any power from your modular’s power supply, a mains powered USB hub/charger like this one can be mounted behind a synth front panel with a couple of brackets (or good glue).


I use an Anker PowerPort. You can get them on Amazon with a variety of different USB socket counts and power outputs. They’re not dirt cheap but they’re reasonably priced.

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Those look good thanks!