Shunyata Everest power conditioner with a Shunyata Sigma v2 power cord. To say that I am surprised at the audible difference in my system is an understatement. Increased depth of soundstage, better placement of the instruments in the soundstage, and although it is difficult to explain, a "blacker" background, which makes the instruments seem placed correctly. This should be looked at as a component, and not just a power conditioner.
Not sure about other preamps but I have found that the Ref6/Ref6SE is extremely tunable with feet and power changes. I have an Everest with an Omega PC feeding mine and it was quite a huge upgrade from the Denali and older shunyata that I had before. Now I have some Sigma X QR power cables coming for my Ref160 monos and I am sure that will also be a huge upgrade. ARC just seems to be very tunable/upgradeable in this way!
A few weeks ago, an Eversolo DMP-A8 DAC/Streamer/Music Server and added an internal Samsung 990 Pro M.2 2280 SSD, and an internal LHY LPS-A8 Linear Power Supply
A week ago an ET3 Cd transport landed on my Shelf. A few months ago a Holo Audio Red also came in the mail. At the same time I got an Yggdrasil+LIM to try in my system. Loved it and it never left. All of a sudden all my digitalis was replaced.
I don't have a large vinyl collection but decided back in February that I wanted to give them an occasional listen while doing so with ease of operation. To satisfy my needs I purchased: a Music Hall Stealth turntable which came with Ortofon 2M Blue , I have since purchased a 2m Bronze ; a Clearaudio Smart Phono V2; Stack Audio Serene Stabilizer; Les Davis Audio 33 1/3 mat and a Herbies Way Excellent 2 mat; Triode Wire Labs phono cable; and an additional set of Stack Audio EVO isolation devices for under the Stealth's feet. I moved Tchernov Reference 2s from my 2nd system to connect the Smart phono to either my preamp or integrated amps in my main system, and purchased Triode Wire Labs RCA cable for my 2nd system
Sean Jacobs DC4/ARC 6 LPS for my DAVE (with Scaler). Immediately and utterly transformative to my system. Despite all the glowing reviews (upon which I based my purchase decision without an audition) I was not prepared for the effect this had on my system.
Next purchase is a second REL S/812. UPS tells me it’s out for delivery right now!