Light Harmonic LightSpeed USB Cable
Availability: Authorized Dealers
Price: 0.8m = $999, 1.6m = $1,399, 3.8m = $1,999
Equipment Used in Evaluation: MSB Technology Analog DAC with Analog Power Base, early 2011 MacBook Pro 2.3 GHz Quad Core i7, 16 GB RAM, Samsung 840 Pro SSD, Promise Pegasus Thunderbolt Drive 8TB, GRAID 8TB Thunderbolt Drives. Audirvana Plus/OSX Mtn Lion, JRiver, JPlay/Windows 8 Pro 64. Interconnect cables: Synergistic Research Tesla Apex LE, and Tesla Precision Reference LE. Speaker cables: Synergistic Research Tesla Apex LE. Power cables: Synergistic Research Element C.T.S. Digital, Tesla Hologram D, T3, and Precision AC cables. 2 Synergistic Research Tranquility Bases, USB Active SE cable and Thunderbolt Active SE cables. Other USB cables on hand were the Audioquest Diamond, Synergistic Research Active USB SE, and the Wireworld Platinum Starlight.
The LightSpeed USB cable is Light Harmonic’s latest entry to an ever growing and somewhat crowded filed of audiophile USB cables. Light Harmonic, well known for their outstanding Da Vinci DAC that I previously reviewed last January (see review), has created what they feel is a USB cable that very few other manufacturers can match in terms of bandwidth. Light Harmonic claims that the LightSpeed with its Ultra-high speed differential pair provides 20 times the bandwidth of USB 2.0 high speed. With its 10 GB per second bandwidth, it offers performance that many other high end USB cables cannot come close to. In fact, Light Harmonic has measured many high end USB cables and found that they cannot meet the USB Audio 2.0 High Speed standard of 480mbps. The LightSpeed physically splits the line with separation of the 5V power supply to reduce noise and disturbances of the digital signal.
The LightSpeed is offered in two configurations
1. The Standard split line with a shared connector at each end. 2. A 3 connector version with two USB-A connectors at the computer end; one for the signal, the other for the power line. One USB-B termination of both lines for the DAC.
I evaluated the standard split line version with a shared connector at each end.
|Conductors||Signal: 0.51 mm silver plated 99.9997% pure copper
Power: 0.6 mm 99.9997% pure copper
|Connectors||USB-A: 30µ 99.9% Gold Plated A Grade Phosphor Bronze
USB-B: 30µ 99.9% Gold Plated A Grade Phosphor Bronze
|Dielectric Construction||Layer 1: 0.55 mm Gas Injected Polytetrafluoroethylene
Layer 2: 0.08 mm Biaxially-oriented Polyethylene Terephthalate
Layer 3: 0.32 mm Gas Injected Tetrafluoroethylene
Layer 4: 0.08 mm Biaxially-oriented Polyethylene Terephthalate
Layer 5: 0.35 mm (+/- 0.1) Polyvinyl Chloride
|Final dimensions||Square-shaped, 3.5 mm (+/- 0.1) X 5.0 mm (+/- 0.1)
|Rated Bandwidth||10.083 Gbit/s|
DSD Playback Issue
Just how important these specification of speed and signal integrity with reduction of the 5 volt line noise was made plainly evident to me. I have been having some issues playing native DSD files with Windows 8 64bit Pro / JRiver Media Center 18 / JPlay 5.1. Intermittent dropouts have been occurring with intermittent clicks with some of my otherwise excellent sounding USB cables. I tried to increase the buffer size for JPlay 5.1, but had no success eliminating these playback issues. I decided to try the LightSpeed to see if its superior bandwidth and claims of noise reduction would solve this issue. Inserting the LightSpeed between my MacBook Pro and MSB Technology Analog DAC completely eliminated these playback defects with absolutely not one dropout or click.
I asked Gordon Rankin of Wavelength Audio if he had some insight into the problems I was having with some of my cables. Gordon is one of the most knowledgeable engineer-designers on matters of USB that I know.
“The problem is what we call turnaround and has to do with the overhang of noise from when the computer sends what's called an IN packet request to the DAC. At that point the USB cable turns around and the DAC sends back the feedback pipe which is getting lost in this case because the overhang of the computers IN packet is lingering (probably too much capacitance or impedance is wrong) and corrupts the feedback sent to the computer. Since the feedback packet is corrupted the computer ignores this and continues to send out data as normal. This causes either and over run or under run of data to the dac chip which causes pops and clicks. Windows does not seem to handle this as well as OSX for some reason.”It would appear that the selection of the USB connectors also influence the performance of the LightSpeed.
A Soundstage to Die For
I recently replaced my Levinson 32 preamp with an Ayre KX-R preamp. The Ayre has balanced outputs which did not allow me to use my run of single ended cables to my Wilson Watch Dog 2 powered subwoofer. The XLR to RCA adapters I had were incorrect for this application. Now the Wilson sub helps to create a deep and wide soundstage with my Wilson Sasha speakers. Even though the Watch Dog comes in at 35Hz, it has a substantial effect on the perceived soundstage of my system.
Using the LightSpeed provided an enormous soundstage that just about matched what I was hearing with the subwoofer in the system. The depth and width were excellent with lateral reproduction of instruments that went well beyond the outer border of the speakers.
Playing the Weavers Reunion at Carnegie Hall 24/96 Classic records DAD, I was simply amazed at the soundstage given the fact that the sub was out of the system. The depth was some of the best that I have ever heard with this recording. But this leads me into the next characteristic of this cable.
A Low Noise Background
Listening to the same Weavers at Carnegie Hall title I was also struck by the low background noise of the cable. I heard subtle hall reverberation with this cable that was masked with some other fine cables in my possession.
The excellent Reference Recordings Doug MacLeod There’s A Time 24/176.4 allowed the guitar and voice of Doug MacLeod to emerge from a deep black background that highlighted the definition of his guitar playing. The pace and rhythm reproduced by the LightSpeed was impressive. This is really a wonderful recording. The only USB cable that I’ve heard that surpasses this background silence is the Synergistic Research Active USB SE with its Active Shield powered by the Transporter Ultra SE. But the LightSpeed would be considered superior in this quality compared to most other high end USB cables.
Dynamic Reproduction with Weight and Wallop
I don’t think I’ve ever used the term wallop to describe the punchy dynamic quality of a USB cable. Aaron Neville’s My True Story 24/192 had impact and a sense of rhythm that was possibly the best I have heard with this recording. The LightSpeed is fast with no overhang. Its dynamic qualities are first rate with the ability to draw one into the musical presentation. The rhythmic drive that this cable can deliver is something that must be experienced to fully appreciate.
Hans Zimmer and James Newton Howard’s The Dark Knight Soundtrack 16/44.1 delivered fast powerful dynamic bass lines in track 1 "Why So Serious?" Again, even without the subwoofer in the system, the bass moved the walls and rattled the windows in my room.
Detail and Definition
The LightSpeed reproduces instruments and voices with exceptional clarity and definition. The LightSpeed is not bright; it does not soften the high end nor is it euphonic sounding as some USB cables I have heard. Complex symphonic musical passages are beautifully unraveled with this cable. I listened to the Mercury Living Presence native DSD Howard Hanson / Eastman-Rochester Orchestra playing the Song of Democracy. The chorus was well separated from the up-front orchestra. The voices were easily understood. The orchestra was reproduced with excellent dynamics and sounded very real. What a superb recording from the golden age. The LightSpeed‘s exceptional clarity and resolution allowed this recording to easily surpass my early vinyl pressing; especially in the loud passages.
What About DXD Playback?
DXD files or Digital eXtreme Definition is an audio format recorded at 352.8kHz. 2L Records utilizes 32 bit floating point at 352.8kHz for their masters. This leaves headroom for their editing and balancing before converting to DSD. HighResAudio.com sells the 24/352.8 files for 2L recordings. I was interested to see how the LightSpeed would handle DXD files; certainly a more difficult task to deliver to a DAC than DSD64 files.
The Hoff Ensemble’s Quiet Winter Night was downloaded at the master sample rate of 352.8kHz/24. I have enjoyed the 24/192 version purchased from HDtracks and was interested to see if I could hear a difference between the two formats. More importantly, I want to see if the LightSpeed could handle the DXD format.
Not all DACs are comfortable playing back 192kHz files, let alone, 352.8kHz files. The MSB Technolgy Analog DAC with its modified Signature Ladder DAC modules and precision femto clock can handle these files easily.
This title was the first true DXD recording I have ever listened to. While the 24/192 version was very good, the 24/352.8 easily bettered it. The ambience seemed to dry up in the 24/192 version with a collapse of the soundstage. Now the soundstage is very good in the 192 version, but nowhere as good as the DXD version. The percussion that plays in the background-left became less defined and a little muted with the 24/192 version. The decay of the percussion was not as prominent with the 24/192 file.
I’m not suggesting that music needs to be recorded at 24/352.8, but when carefully executed as 2L Records seems to do, the result can be stunning. And the point to take home with this discussion is that the LightSpeed was able to discern the differences in these files with no dropouts or noises.
The LightSpeed Has Weight and Body
I played Mel Torme Swings Shubert Alley 24/192 (HDtracks) and was quite surprised with the result using the LightSpeed. Not only was the orchestra’s instruments extremely clear, but Mel’s voice had body and weight and sounded less 2-dimensional than with some other USB cables. I suspect that the cable’s speed and low noise just allows more information to get to the DAC . Also, timing errors are probably reduced with the LightSpeed.
A High Resolution USB Cable
The Light Harmonic LightSpeed is capable of exemplary resolution when paired with a fine DAC. Its special qualities of speed, detail, soundstage and ambience reproduction, along with its low noise capabilities, place it among the finest USB cables I have yet heard. Having had an opportunity to live with the Light Harmonic Da Vinci DAC, I can see how this USB cable would beautifully complement the low grain-analog sound quality of the Light Harmonic Da Vinci DAC.