Fiio x7 portable high resolution music player with am1 amp module experience digital music to the fullest with mastering quality lossless playback designed originally for high end home audio the x7 is one of the first devices to utilize the original ess es9018s in portable audio its 8 output channels can be bridged 4 a side for an astonishing 135db sn ratio and dynamic range while the thd is as low as 120db compared to the es9018k2m popularly used in portable devices the original es9018s f