I own a tempest 2, have owned the sphinx 2 and the RP1. I can attest to how incredibly noisy all of this gear was. The sphinx 2 was less so and was actually manageable as my speakers weren't very sensitive at the time. The RP1 created a ridiculous amount of noise unlike any other preamp I've ever owned. It was sold. The tempest likewise has a crazy unlistenable amount of noise compared to any other amp I've ever owned, even when just using the onboard passive preamp, a hum X, conditioned power, it generates massive noise that is clearly audible at 15'. I've decided to take a break from Rogue Audio products because of it.