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Reviewer: Srajan Ebaen
Financial Interests: click here
Source: 27" iMac with 3.4GHz quad-core Intel Core i7, 16GB 1.333MHz RAM, 2TB hard disc, 256GB SSD drive, ADM Radeon HD 6970M with 2GB of GDDR5 memory, OSX 10.8.2, PureMusic 1.89g in hybrid memory play with pre-allocated RAM and AIFF files up to 24/192; Audirvana 1.5.5 in direct/integer mode 1, Metrum Acoustic Hex, AURALiC Vega
Preamp/Integrated: Nagra Jazz, Esoteric C-03, Bent Audio Tap-X, TruLife Audio Athena, Bakoon AMP-12R
Amplifier: First Watt SIT1, FirstWatt SIT2, Goldmund Job225, Crayon Audio CFA-1.2, AURALiC Merak monos [on loan]
Speakers: soundkaos Wave 40, AudioSolutions Rhapsody 200, Boenicke Audio B10, Zu Audio Submission, German Physiks HRS-120
Cables: Complete loom of Zu Audio Event, KingRex uArt USB cable, Tombo Trøn BNC/BNC S/PDIF, AudioQuest Diamond glass-fiber Toslink, Van den Hul 110-ohm AES/EBU
Stands: Artesania Exoteryc double-wide 3-tier with TT glass shelf, Rajasthani solid hardwood console for amps
Powerline conditioning: GigaWatt PF2 with Vibex Two 1R on amps, Vibex Three 11R on front-end components
 Sundry accessories: Extensive use of Acoustic System Resonators, noise filters and phase inverters
Room size: 5m x 11.5m W x D, 2.6m ceiling with exposed wooden cross beams every 60cm, plaster over brick walls, suspended wood floor with Tatami-type throw rugs. The listening space opens into the second storey via a staircase and the kitchen/dining room are behind the main listening chair. The latter is thus positioned in the middle of this open floor plan without the usual nearby back wall.
Review component retail: $1.399/1.6m

Light Harmonic's acrylic spacers physically separate the split cable to further minimize cross-field influences.
After Paul's review published, I'd sent my customary group mail to our writing team announcing new content. My note was plain.
• Paul hits us with a SOTA USB cable he sez makes more of a diff than speaker or interconnect cables.


Aussie contributor John Darko lost no breath chiming in. Ka-tchinggg:
• I have one of those LH USB cables. I agree with Paul. Bigger diff than speaker or interconnect changes. Slipping into street talk, I fired right back.
• Fuck. You mean I now gotta get me one of those things? Geezus. Thanks a lot -:)
• ‘Fraid so.
• Okay then. That's how quickly things can devolve even when you're being careful.
I prefer upsampling in 64-bit player software to on-chip SRCs in the DAC.
In the wake of this John even overcame carefully groomed habit—he dislikes reviewing cables for all the hate mail it inspires particularly with USB and Ethernet—and posted a small LightSpeed piece on his own site. But that wasn't the end of it. 6moons reader Ken Redault was furious.

• You gotta be kidding! Another USB cable rave. Are you guys stoned? What a joke! I posted his outrage in our feedback section with a reply:
• It's a circle jerk. Mono & Stereo just raved about the same cable and our Aussie contributor John Darko agrees that this cable makes more of a difference than interconnects and speaker cables. I haven't heard it for myself yet but I want what those guys are smoking.
soundkaos Wave 40 with Crayon Audio CFA-1.2 preceded by Nagra Jazz
That wasn't the end of it either. Someone was listening in. And not the NSA. A week later Bill Leebens who works with Light Harmonic offered to send me one of these effronting cables. He wanted to know which length—0.8m, 1.6m or 3.8m—I'd fancy. And double-headed or single. Clearly the time had come to challenge my customary KingRex twinned leash for a mano-i-mano. High noon at the USB corral. I opted for 1.6 meters. With forked tongue. Double ends. Bill made it so. Then DAR reader Nickolas piped up on Darko's forum.


• Just got a LightSpeed USB cable in the mail yesterday. Still burning in but can confirm the hype. It's spectacular. Want to echo what the others are saying. $1K is a lot for USB or any cable but you will get a lot more from this $1K than you usually do in audio. Two thumbs way up. Would I need three thumbs for my own come-to-Geezus meeting?
Despite the earlier exchange with the dark one, my own interest wasn't casual. If the LightSpeed was as potent as these guys had said, this single-source PCfi guy better learnt whether and how much precious performance he still brushed under that fancy Artesania rack. High-speed digital transmissions differ from analog. Digital is about approaching square not curvy waves. It's not to slap a pair of BNC or USB jacks on an analog wire and calling it digital. If our idealized red digital square wave ended up looking blue or green—the green is perfectly normal for what most power amps do to square waves—that'd be jitter. Blue like what speakers might do to 'em? More of a jittery egg-walk disaster. Broken eggs, no omelet.


Now add bandwidth far in excess of analog signal in the first place. Then add even more to transmit something approaching square waves (perfect ones would require infinite bandwidth). Digital and analog cables are not the same. So give the jive of just 1s and 0s a rest. Listen with ears not theory. Here I wasn't exactly starting out slumming it. The red KingRex—I'd compared it to their blue and preferred red—has been my reliable workhorse USB cable since its review. After that I'd not given the category another thought. Until now. So I fired up AURALiC's Vega with its clock at 'exact', Audirvana 1.5.10's custom upsampler at 352.8/384kHz for the 44.1/48kHz families, my mind to the proper Hemingway frame and went hunting for big game differences. Would I even see elephants? Or just nasty hyenas?


The short and sweet of it? I did. Perhaps not a fully grown elephant just a baby giraffe but there was an undeniable instant improvement. Murkiness and congestion. The LightSpeed cleared 'em up. It felt as though it pulled out an intermediate obstruction. Think gauzy filter, a sad smoke-stained formerly sheer but now yellow-tinged curtain.


Put at its most basic it sounded louder. Like a rigged comparo. Except it wasn't actually louder. It just had the same effect of hearing everything easier and better. Particularly at lower overall SPL this was quite uncanny.


Asking myself what caused this perception, I hit upon the usual. Transient fidelity. This is about the very beginning of each tone.


High-efficiency single-driver speakers tend to do this very well. With two-way speakers Gallo's Strada II is one of my favorites. If you don't touch anything else— you don't buy this leading-edge acuity by stealing from mass or decay lengths—but just up the system's percussive 'rise time', everything gets clearer and locks into perfect focus as though through a very expensive lens. And that's pretty much what I heard. I didn't hear more tone, more bass, more treble, more width... just higher beat/attack definition that was embedded in unchanged tone/detail density. Hence the removal of a filter which had before blurred this element of tone beginnings. So think starts, not middles or ends. Pricklier faster sharper starts without altered bloom or decay weighting don't sound sharper or pricklier. Just more intelligible. If that's higher resolution—it should be—the LightSpeed cable was plainly more advanced. Did touted higher cable bandwidth equal squarer waves for better-timed digital pulses? I don't know. That's for engineers. I simply report that there was room for improvement beyond what I'd known; and that its dead-obvious magnitude proved significant enough to not want to go back. The LightSpeed did its hype proud. Again. Bring on the hate. Or post to Darko's review. He'll luv that.


As for me, elephants could still be in the future. Bill Leebens: "This thing needs a lot of active burn-in. And by that I mean full-signal usage with a varying input, not just the hookup. It will likely change character pretty dramatically over the course of a couple of weeks. Yes that's a pain in the ass but so far we haven't come up with a burn-in protocol that can be done repeatably and effectively at the factory." If things get positively elephantine after a few weeks, I'll report back...
PS. On computer-audio differences, resident IT experts Marja & Henk had this: "It's a fact that with network communications (computer data transmissions) there are differences in ethernet cable quality. CAT 5 was superseded by CAT 6. When a standard CAT 5 cable for audio purposes gets switched to CAT 6, there's already a substantial audible difference. But it goes well beyond cables. Think hard disks. We notice differences using various hard drive makes/types for audio playback. In our XXHighEnd dedicated Windows PC our WAV/FLAC files store on USB 3 hard drives. From there data is intermediately stored on another disk before being transferred to memory from whence actual audio ‘playing’ is performed. The kind and type of intermediate disk has an influence on the perceived playback. Western Digital sounds less good than Toshiba where SATA disks are concerned. Disks spinning at 7.200RPM sound better than 10.000RPM spinners. Using a solid-state drive is not as fine/good as a slow-spinning SATA. So far the best is a RAM disk created in physical memory. Audiophiles have trouble wrapping their heads around the fact of no real time component since all data is cached and/or buffered somewhere along the path yet everything still has an influence. The only thing we can think of is that it has something to do with transitions between protocols. For an analogy, computer hacking occurs at the most vulnerable side of software - its protocol boundaries. When HTTP (which is nothing more than a copy protocol) transfers data from server to client (a web browser receives or sends data to a server), there's a conversion of protocols. At that crossing point hackers can interfere. It goes far deeper but the general idea is that at each crossing point from HTTP to XML, SQL or whatever protocol is involved, there's a weakness and an opening. The same seems to be true with audio content at a low level. In computer audio data migrates from one protocol to another. At every protocol translation point there's an influence."
Light Harmonic website