I may be wrong, but I think the Hi-Z input may exacerbate the hum coming from a grounding issue. They are usually used for guitars, piezo pickups etc. Do you have any regular line level inputs you can use instead?
Yes, I thought the same. But in this particular case the Hi-Z is actually reducing the noise hum and also giving the extra gain that I need in comparison to the Line level input
Voltage Converters are pretty noisy so the hum may be coming from that.
You can use the power supply without the voltage converter: the power supply’s input is rated at 100-220VAC, 50/60Hz so it will work on the UK power grid. However, you will need a ‘plug’ adapter to match the UK wall socket shape:
My mistake, I meant that I was using a ‘plug adapter’ like the one you have posted, not a voltage converter. I’m not aloud to post a pic, but the input of the power supply is: 100-240v~50/60hz 0.5A
The plug converter has 13A, 250V written on it.
I’m a noob when it comes to electronics, so I don’t know what is compatible.
For me battery’s running most of my equiptment during recording solves all these problems and is the quietest solution ive found. Power conditioning too but its not perfect.