In my best Captain Renault voice I am shocked SHOCKED that people on this forum don’t know the power supply of the Nano is an external USB-C 5v2A rather than an internal one and would gatekeep the hobby in saying unless you can drop your monthly income for a power supply or a source component than don’t bother rather than actually helping the person with the original question seeking knowledge.
I went with the iFi Power X. I can't say how much it helped over the stock wall wart because I never used it. That said the Nano with it's built in DAC on it's own is fine, I'm just waiting for my new DAC to ship.