Nirvana S-X Ltd. interconnect
Nirvana's first product, their Transmission Digital Interface, went on sale in 1992. Although virtually no advertising surrounded its launch, it quickly became an underground success. Ever since, Nirvana's steady growth has been fueled almost entirely by firsthand exposure to their products and word of mouth. Not surprisingly, the company isn't prone to update-of-the-month syndrome, or to trundling out "revolutionary" new products each year. The S-L speaker cables and interconnects I've been using since 1994 are the same ones being sold today. Similarly, the other products in Nirvana's tiny linetwo power cords and three digital cableshave remained unchanged since their introductions.
So when Mr. Nirvana, Stephen Creamer, casually mentioned, "Oh, by the way, I've got a new interconnect cable," I took notice. When he added, "I hate to admit itbecause S-L really is the cable I wanted to makebut the new stuff is a lot quieter," I started negotiating for review samples.
The S-X Ltd. was designed, from the outset, not as a system-wide replacement for the S-L, but rather as a front-end cable for carrying low-level signals between source components and the preamp. "The entire philosophy of noise cancellation was developed around low-level, pre-preamp signals," said Creamer. "Reducing noise is key to just about everything in terms of audio performance. S-L was designed to be as quiet as possible in system-wide applications, but I had in the back of my head that I really wanted to design a low-level cable...one optimized for that application, that would be even quieter, that would give you a super-duper black background."
The final product shares many aspects of its construction with the S-L, but is different in several key areas. Both use a Litz construction, with "95 isolated, multi-gauge, multi-strand, oxide-free, Lab Grade fibers per conductor with FEP insulation." But there are two conductors in the S-L, three in the S-X. Both use opposed-helix shieldingin which the angular relationship between the wire overlays is said to cancel noiseand a static-resistant particle-loaded polyurethane jacket.
The arrangement of conductors and shielding is proprietary, but both the S-L and the S-X Ltd. use aerospace-grade amorphous PTFE and air insulation. The difference is that the S-X gets a much more elaborate, multi-layer treatment. To manage the additional layers' added capacitance, the S-X adds a complex internal wire guide system that spreads and specifically locates the componentswhich also ensures a high level of spatial and electrical consistency along the cable's length, and from cable to cable.
Each S-X Ltd. cable is hand-assembled, extensively tested, and personally inspected by Creamer. The process requires about a daynot counting the curing time for the epoxy used to seal and mechanically stabilize the terminations. Termination is an intricate process that involves not only dealing with the Litz conductors and multiple shields, but essentially rebuilding the WBT (RCA) and Neutrik (XLR) conductors to fit the S-X Ltd. Even a cursory description of the procedure filled a page of notes, so I won't describe it here. But it spawned a project to design a significantly better connector; it's being beta-tested now, and may be available by the time you read this.
Use and Listening
Like all Nirvana cables, the S-X Ltd. interconnect is beautifully built and finished. It's larger than the S-L11mm in diameter vs 9mmand a bit stiffer, but still quite manageable. Even so, Creamer is apologetic for its size. "I hate stiff cables, and I worry that this stuff is getting too thick. I work a lot with high-voltage cables, 235kV, and they aren't as thick or rigid as some audiophile cables. But S-X is used for pro-audio [Chesky and Mercury-Japan are among the labels that use S-X as microphone cables] so it has to be tough, and the shielding and the spacing of the components requires that it be this way."
Although the S-X Ltd. was designed primarily as a low-level or "front-end" interconnect, I used it throughout my system: a 3m length between my VPI/Grado analog rig and the VAC CPA1 Mk.III preamp, 1m between the lovely SimAudio Moon Eclipse CD player and the VAC, and a 6m run between the VAC and a pair of Classé CAM 350 monoblocks. All interconnects were single-ended. I did most of my listening using the Magnepan MG 3.6/R loudspeaker, biwired using a number of different speaker cables. All cables were burned-in in situ for about 200 hours prior to any serious listening.
Nirvana S-L has long been a staple of my cable collection, so although the S-X wasn't intended to replace it, the S-L's performance is a natural jumping-off point. The S-L's strengths include its superb noise cancellation/rejection (it truly is incredibly quiet, even in the harshest environments), very low distortion, and wonderful coherence. On the minus side, it gives up a bit of precision and speed at the frequency extremes, the leading edges of transients are a bit softer than with some cables, and detail is not quite as sharply focused as the best I've heard. The result is a wonderfully coherent, low-distortion cable with an overall presentation that's a little to the soft, liquid side of neutral.
In comparison, the S-X Ltd. matches or improves on the S-L's strengths, and amelioratesno, obliteratesits weaknesses. Quieter? I can't say for sure, but I could hear farther into the soundstage with the S-Xas if the background seemed clearer and more open, and even "blacker" than the S-L's lush silence. The soundstage was wider and deeper, and there was a much better sense of the space around and between instruments, particularly with respect to front-to-back layering. At the rear corners of the stage, rather than having a sense of an image surrounded by air with a wall next to it, the S-X gave me a clear picture of three distinct elementsinstrument, wall, and the space between themand their positions. And where the S-L seemed to have a slight liquid texture, the S-X's soundstage was neither liquid nor dry, just crystal-clear and wide open.
The S-L's seamless coherence and natural portrayal of images has been transferred intact to the S-X Ltd. The S-X was every bit as coherent as the S-L, and did an even better job of imaging, with noticeable improvements in dimensionality, inner detail, and edge definition. Images were more dense and tangible, but remained as well-integrated with the surrounding space as with the S-L.
In the areas where the S-L was a bit less superb, the S-X wasn't just better, it was a lot betterin fact, it was one of the best cables I've ever heard. For starters, resolution of inner and low-level detail was outstanding, as was its ability to uncover subtle microdynamic transients and shadings. Vocals were particularly well served. Try Ernestine Anderson's Never Make Your Move Too Soon (Concord Jazz CCD-4147): In passage after passage, the S-X surprised me by revealing additional layers of subtle intonation and vibrato. I felt as if I could hear into the notes, hear the air moving through Anderson's body, and the contributions that her chest, throat, and mouth all added to her tone. There was a better sense of hearing through the system to a real person singing; I could easily close my eyes and picture her moving around, head back, pausing a split second to gather herself for the next note or transition.
Chesky's killer new live CD of Clark Terry duets, One on One (Chesky JD198), really came to life with the S-X Ltd. This disc has a natural, acoustic sound and a great sense of spaceboth of them served well by Nirvana's trademark coherence, and particularly well by the S-X's improved openness and air. The real kicker was how the S-X captured the low-level ambient soundspeople moving, brushing against objects, talking, whispering, singing alongthat occur all around the stage. With other cables, including Nirvana's S-L, the sounds are still there, but only just above the level of audibility. When I dropped in the S-X wires, the background sounds took on dimensionality and detail, and theyand the entire ambient environmentjust seemed to come alive. I was listening to the second track, Lilian Hardin Armstrong's "Just for a Thrill," and caught my heart skipping a beat when Terry's trumpet entered after the piano solo. He was right there.
Another piece of the S-X's wonderful life and presence, and another area where it was a significant improvement over the S-L, was its precision in the leading edges of transients. Where the S-L sounds a bit soft and rounded, the S-X was clean and fast. At the opening of "Walk Away Renee," from Rickie Lee Jones' EP, Girl At Her Volcano (Warner Bros. 23805-1), the bells popped out from the background and danced in three dimensions, exactly as they should, their ring cutting cleanly through the ambience.