With a few more days of burn in I am quite satisfied with the sound quality of the M7S Amanero input with the Icron Ranger + OPA2140 DC Servo opamps. I believe I will skip upgrading to any USB-I2S DDC no matter what new chip/clock it will be using as it is still USB Audio 2.0 the limiting factor. Let see in a few years if the next wave of Thunderbolt-I2S interface or HDMI 2.X audio (directly output from video card supporting 8K and 22.2 channel audio) shall give a definite advantage over my current setup. As the M7S is limited to192kHz PCM in 8XOS mode, the current Amanero is still capable for this data rate. I can understand DSD128 and above streaming can easily overrun the current Amanero. I am too lazy opening the M7S setting jumpers to try 4XOS or NOS. I compared 8XOS and 4XOS by playing some 352kHz materials with/without using J. River doing downsampling to 176kHz. (as PCM1704 auto switches to lower oversampling when playing above 192kHz), and I like 8XOS with J. River downsampling better. 4XOS makes each intrument sounding bigger, like sitting closer to stage. I prefer the more precised imaging of 8XOS, which is more "capatible" to different genres/masterings of music.