I built my first Helix pc perhaps a year ago, easily heard upgrade over Shunyata Python and Vh audio Airsines I was using. At this point I'm using Helix pc on every major component in system, everyone added only further upgrades sound quality. Originally, I was using Duelund AC rated on hot, started noticing a bit of darkening, rounded bass, highs rolled. Replaced Duelund with Vh audio airlock, lightened up on bass, opened up top end a bit, sound a bit more refined, greater resolution.
Whether built with Duelund or Airlock, the most noticeable improvement heard over many other pc's I've tried over the years is the amazing transparency, never heard pc's sound so open. A couple of differences in my recipe are cryo versions of Parts connexion connex ac plugs and bare wire attachment at ac plug. I use two runs of airlock in source components, four runs for tube amps.
Thanks to Steve for a really great diy recipe, easily best diy recipe for anything audio related I've experienced in many a year in audio. Having auditioned many high end pcs over the years, I can't really recall any I wanted to use on entire system. These are so natural in timbre, tonality, really very little coloration.