In a post above, I mentioned that I chose to use Esoteric's ESLA link protocol between my K-01XD Player and my new C1X solo over standard XLR interconnects, thinking it's a proprietary feature so it must be at least marginally better. My initial impression was that it sounded more refined. Didn't do any follow-up, in part because specifying the link protocol to be used in both units is a PITA setup process. But as time passed, I started to feel less involvement with some favorite music, less bass, maybe less air. Was I imagining this or ....? So I went back to standard XLR protocol. Wow! The magic was back! If you have a solo, I doubt that setting up ESLA INPUT links will prove worthwhile. As always, YMMV. (ESLA OUTPUT links, however, may be another story - can't say because I don't own a supporting Esoteric amp).