Treble was very extended, and detail retrieval was very good. Low level details from the presence region, and upward, were quite amazing. However, some of the "analog ease" quality that the reverse cord combo had, was missing. The upper mids could be very slightly "hard" on rare occasions. Another strange tonality was that occasionally, the "chest range" of both male and female vocalists could turn overripe. But the biggest problem was the lack of ryhthmic drive and pace, especially when compared to any combo that included the Shunyata Sidewinder cord (although it kind of exagerrated pace). And compared to most of the other cord combos, the images of instruments did lack solidity. The treble could almost be "wispy", but was very liquid. Stage depth was good (but ultimately U-shaped), and fatigue factor was very low. Layering of depth, especially in the treble, was intoxicating (the U-shape notwithstanding). My attention kept being drawn to instruments whose range occupied it, and away from the instruments in the rest of the range. Stage width was slightly beyond "average". The air between/around instruments was very clear, and the background was kind of medium black. Attack transients were only slightly hyped, and midrange timbre was almost too transparent; or at least not "juicy" enough, lacking warmth and tonal color...but wasn't really cold either. Bass was very extended with good weight, but lacked focus; had a good "round" quality, though. And yet somehow, I COULD CRANK THE VOLUME TO ELEVEN, and wasn't overly bothered by the problem with the lack of pace. It was there in abundance, but it didn't scream at me...kind of a sin of omission. Tonally, overall the presentation was strangely reminiscent of my Sennheiser HD-600 headphones (except for the bottom octave, of course).................About the U-shaped soundstage: I noticed it the most on the RCA UV-22 remastered Rimsky-Korsakov "Scherazade" gold CD, Fritz Reiner conductor. I realize the Chicago concert hall was wide and shallow, but somehow the Proteus/Black Mamba combo missed what little depth there was in the back corners. I freely admit that the ac cords don't deserve 100% of the blame here, but....while listening to this CD, I was nowhere close to believing I was back in that 1960 concert hall, especially during "The Young Prince and Princess"........My quest continues.