Quality power question #2

Those wall warts are fine! Rega knows what they are doing! No need to spend hundreds on a linear supply, contrary to what the "golden ears" crowd claims. 

I use the Farad Super 3.

https://www.faradpowersupplies.com/

The Rega fono mini is a $200 phono pre-amp, so I’m not sure how much more performance you can squeeze out of it.

You can always try an upgraded power supply, as @carlsbad2 pointed out, but I’m not sure I’d expect miracles.

Pretty quickly, you're going to run into a situation where you're throwing good after bad, so to speak.

JM2CW.