Pros:  Crystal clear, exceptional imaging and depth, resolution and detail (especially bass texture) power for HiFiMAN Susvara, grace for Focal Utopia, excellent outputs, built like a tank Cons: not for low impedance high sensitivity IEMs, price List Price: $3499 Product Website: http://www.theevolutionofsound.com/xiaudio-formula-s/ Introduction Alex Twister introduced me to Michael Xiao, proprietor of Eleven Audio, formerly... Continue Reading →