I finally got (and extensively burned in) my twisted Opus cable for my Neumann NDH20 Black Edition, and at long last, I can now say this portable rig is DONE... because every single part if it is utterly maximized in terms of accomplishing its True Portable (but wired) high isolation closed back headphone mission, as well as looking very pretty.
Although the treble is quite obviously less smooth, the overall sound hasn't really become analytical like my old original NDH20 sounded with its stock cable on my Hugo 2. As expected, the iFi Gold Bar is still smoothing out the top end a little bit, leading to a lifelike but pleasant sound. The Cardas Copper cable I was using before this was also increasing the bass significantly, but I now realize it was only increasing mid bass, not the low bass or sub bass. With the Opus, by comparison there is now an emphasis on the lower bass frequencies, so the impact and slam is fully equal to what it used to be, though overall the audible bass is less loud. Having less mid bass is less fun, but more realistic, and the still strong slam means it's still equally exciting.
But the great thing about the sound now is that it's more interesting and versatile due to the increase in detail and the pivot toward a realistic, balanced sound signature, without really losing the "mule kick" aspect of the incredible bass. Now I never once feel when checking out a new musical artist that I'm "slumming it" with my smaller, portable rig, I never feel like the music necessarily demands my more technically advanced main rig with my expensive Chord DAC, Opera Cable, etc.
The improved clarity, maybe in the treble particularly, also makes the wildness of hearing a decent sized soundstage from a super isolating closed back even more miraculous, making the most of iFi's stage-expanding Xspace crossfeed voodoo. I watched a couple movies on this tiny thing last night, and it actually sounds cinematic, not only in the rumbles and booms of the low end, but in the size and scope, in the spacial dimensionality. I'll be taking some more classy photos of this rig soon, like it deserves, but in the mean time here are a couple quick shots.