Paul...I've owned Black Mambas for about a year and also Cobras for maybe 6 months. I also have several Master Couplers in there to boot. There are some substantial differences between all 3 cords. The Master Couplers have improved bass response, somewhat lowered background noise and have slightly smoothed out the overall music presentation. They are a good buy and a significant improvement to your system. The Black Mambas take the forementioned to the next level. Still tighter bass and wider soundstage. You are able to single out and focus in on the individual instruments. Hidden detail is brought out. Next is my favorite, the Cobra. This power cord is a pretty substantial jump in performance over the B Mamba. I've heard so much new information on my CDs that it amazed me. There is an 'air' around the music and bass response is excellent. I have one plugged from the wall to my VansEvers line conditioner. Everything that I plug into the conditioner has been upgraded 125 to 150% in virtually all areas of the listening spectrum. You really have to experience these for yourself. That's what they do for my system, they may be different in yours. You can find Cobras for less than 1k here at Audiogon. They are well worth the money!
