You mentioned Pass Labs so I thought I would link to this https://www.google.com/amp/s/www.cnet.com/google-amp/news/luxman-p-750u-headphone-amp-drool-worthy/ I'm having a demo this upcoming week. FYI, and IMHO, I heard the Nimbus at CanJam fronting a Chord TT2. The system didn't do much for me. In the same room was the new HeadAmp GSX Mini fronted by the new Brooklyn Bridge DAC. Significantly more impressed with that setup.