Low rider: Indeed a linear power supply may result in an improvement. Its a 16V wart. I’ve got 3 warts on my system. To date I’ve addressed this by doubling up a Furhman power conditioner with EFI-EMi clamps on all my plugs/connectors, and isolate the warts as far away from my components as possible using a dedicated power strip for the warts also plugged into the Furhman. I’ve plugged and unplugged the warts at full power/volume and don’t hear them. Thats not to say soundage isn’t impacted. I’m dead quite on all inputs except my Mc phono, but don’t feel its coming from any of the warts. Tubes seem to be the #1 variable in the phono section noise department. I’ve done an AB comparison of the LOKi in/out of the system and detect no issues. Its clean. I strive for extreme detail as my MO and accomplish this via driving a large pair of ML electrostats bi-amped with a pair of NUForce STA-200’s, and a tube pre-amp that includes grid frame’s in the first section of the tubes and the Russian 75 HG Saratovs in the 2’nd part of the phono stage. Have also installed the little VIshay low uF bypass capacitors on both the Martin Logan high and medium stator caps, and run the same along with bypass capacitors and Mundorf Supreme EVO gold, silver & oil caps in the audio output stage of the pre-amp. Net, I can hear a flea walk across the recording studio. The soundstage is crisp, detailed, and deep. Not everyone likes this, I strive for it. But its extremely revealing of system, source, or recording issues. Not detected w/the Loki. But I have to admit in the quest for improvement, a linear supply may result in another step up. The challenge is numerous different voltages in the wall wart row. You think the industry would standardize. Need a Swiss knife LPI that can handle various voltages from one unit. The Schiit Loki is not a tube pre-amp, but I wanted to mention it because the topic author suggested EQ was important to their interest and its the first EQ that meets my expectations without molesting the SQ IMHO for what its worth.