Simplest Linear PSU?

@itsjustme +1 I use Uptone JS2, choke based lps on some of most important digital components. This will explain issues with T,BR&F  and advantages of choke based,https://audiobacon.net/2021/08/06/the-worlds-best-audiophile-linear-power-supplies/3/

I am a fan of small chokes to eliminate the HF noise generated by most series regulators. 

I should add that the link above describes what appear to be very well thought out supplies, at a not-insane price considering what's inside them.  I pay little attention to the stand alone LPS market since i design LPSes for use within products. And when i need my own personal outboard LPS i just build it ( i have genero PCBs that i fab and can adapt to most uses).

Regulation done right reduces noise on the supply, rather than adding noise.

Hmm, no love here for SBooster?

s boosters are excellent, cost effective, very very well built and terrific performers