Watched a power supply comparison on Old HiFi Guy's youtube channel.
I purchased 2 one for a Fosi Audio GR40 and the other for a Fiio K11 R2R.
The Fiio's switching power supply is 12 volt 2 amp so I did not try it with the Fiio.
Tried it with the Fosi GR40 on my modest near field system that is powered by a Fosi ZA3 amp with Sparko's opamp's, Sony SSCS 5 for mains and Polk Audio RM705 subwoofer.
The difference in sound stage, instrument placement, vocals and especially bass response was shocking. This PSP linear power supply made music like Stanley Clarkes School Day's, to stuff like Dave Brubeck's Time Out to the Who's Live at Leeds My Generation bass solo by John actually sound like a bass instrument instead of the expected performance of an inexpensive subwoofer.
Moving from a Douk Audio P1 tube preamp to the Fossi GR40 preamp/dac made a immediately noticeable improvement. This linear power supply gave a comparably obvious improvement to the overall sound.
Easily the best bang for the buck improvement to the overall sound I have ever purchased.