My ES100 is now working again with my Linux computers. What fixed the issue was... a device reset. I really should have thought of that earlier. Weird bug anyway. What I'm really not impressed with is Radsone's customer support. Never got an email back. Anyway, I'm not using my ES100 with my laptop anymore as I've received my Topping NX4 DSD. It sounds terrific and the amp is wayyyy more powerful than the ES100. The ES100 has plenty of power for IEM and sensitive headphones (that's what it's designed for after all), but it's a little lacking for my harder to drive headphones that I use with my laptop setup, like my Monolith M560 and Sennheiser HD58X.