Linear USB power supplies...

[jack]

I'm after a decent low noise linear PSU with USB outputs to power an Focusrite Scarlett 2i2 4th Gen interface...

Currently it's fronting a RPi which is generating a load of hum, rather drowning out the faint audio I'm trying to record. The box uses USB C to connect to the Pi and uses the same cable for power unless there's another PSU plugged into a power-only USB C socket, in which can it uses that for power.

My logic is therefore to use a linear 5V USB supply in that second socket. Obviously, I could build one, however by the time I've done that and boxed it nicely, I suspect I'd be £50 and a load of time into it, so I might as well buy one.

What to do?

Edit: moving the power from the Pi to a "less digital" source has improved matters greatly ... still some hum though...