When the first DACs (digital-to-analog converters) appeared in 1985 they were big and expensive. Sony’s first DAC, the Sony DAS-702ES, weighed over 11kg and was built to last a lifetime. Too bad the technology inside the DAS-702ES remained cutting-edge for less than a year. Digital technology has continued to march forward, evolving and improving to the point where the early “Perfect Sound Forever” digital components sound pretty groady by today’s standards.
While I wouldn’t be so rash as to state that any new DAC will sound better than even the most expensive ten-year-old model, it’s not uncommon or surprising to find that many owners of older kilo-buck DACs are “trading up” to far less expensive DACs that provide superior performance compared to their outdated units. Combined with a computer-audio music library a USB-capable DAC can deliver a level of performance that a scant few years ago was available to only to a few of the very-well-heeled.
Here are four DACs, ranging in price from $699 to $3600, that offer better performance than you could obtain at anywhere near their prices just a few years ago. All represent the current state of DAC manufacturing and design. And regardless of their price points, they all attempt to optimize their listeners’ musical experience.
CHANNEL ISLAND AUDIO TRANSIENT MARK II USB CONVERTER AND DAC ($699)
The first DAC in our survey is from Channel Islands Audio. This small enthusiast-focused company specializes in high-value, made- in-the-U.S. audio components. Opened in 1997 and located on the central California coast in the town of Port Hueneme, Channel Islands Audio may be best known for its low-noise aftermarket power supplies for the Logitech Touch and SB3, but it also makes power amplifiers, preamps, DACs, and headphone amplifiers.
When I asked Dusty Vawter, chief designer at Channel Islands, whether the new Transient Mark II was principally a USB converter or a DAC, he told me, “I see it as a USB audio multi-tool. Its strength begins with the XM-2A board, making it a state-of-the-art USB to S/PDIF or I2S converter. We wanted a product that could be totally portable and provide the industry- standard 2V analog output. After testing the available DAC ICs, we chose the Wolfson for its musicality. We’ve surrounded this circuit with very high-grade parts from Nichicon, MUSE, Takman, Vishay, and Wima.”
Like the other audio components from CIA, the Transient Mark II exterior is simple and lacks the kind of cosmetic frills, such as 1⁄2″-thick front panels, that increase a component’s cost without adding to its sonic performance. The front panel has six blue LED lights that indicate the current sampling-frequency and two buttons to control the volume. That’s it. Since there’s only one input there’s no need for an input selector, and all outputs are always active.
The rear panel of the Transient has a USB input, one pair of single-ended RCA analog outputs, a BNC-terminated S/PDIF output, two I2S outputs (one HDMI and one five-pin mini-DIN), and a 5-volt DC power input for the optional VDC-5 Mk II high- current power supply.
The Transient II’s volume is adjusted via a digital control. According to Vawter, “a side benefit to the Wolfson DAC IC is that it has a 24-bit digital volume, which can be accessed in software mode. In that we already required a micro-controller to run the sample-rate indicators, it made sense to make use of the built-in volume control. The high-resolution control works very well and doesn’t have the L-R tracking error of potentiometers.”
Starting with the very well regarded Wolfson DAC and XMOS chipset as the basis for its design, Channel Islands added its own ideas to the mix. “We developed our own USB-to-I2S board utilizing the XMOS processor. Our XM-2A daughter board uses a compact four-layer PCB and dual ultra-low-jitter (<1 pico- second) oscillators, and can be powered by the USB or external low-noise supply. Then the low-jitter I2S signals from the XM- 2A are fed into independent buffers for each I2S output, a low- jitter S/PDIF transmitter (for BNC output), and also into the on-board Wolfson DAC circuit.”
Since the Transient II is a USB-only DAC it spent most of the review period tethered to my MacPro desktop computer. It did not require loading any drivers, and the Mac Sound Control Panel immediately recognized the Transient by the name “CIAudio USB Audio 2.0” and showed support for bit-rates up to 192/24. I used the Transient with iTunes, Amara, Pure Music, Decibel, Audirvana Plus, Audacity, and Audiogate without a single compatibility issue.
How does the Transient II sound? Well, it sure doesn’t come across as a “budget” component. Used as a USB-to-S/PDIF converter the Transient rivaled the more expensive Human Audio Tabla ($995) in S/PDIF when it was running into the April Music Eximus DP-1 DAC/preamp (the DP-1 has two S/PDIF and two analog inputs, so it’s ideal for real-time A/B comparisons). Although the latest Empirical Audio Off-Ramp 5 combined with the new Empirical Audio Short-Block isolation filter did have a slightly larger soundstage and lower noise floor, I had to use my own live recordings to clearly discern the difference—on commercial recordings the two USB converters sounded almost identical.
For optimum performance Channel Islands recommends using the Transient II’s I2S outputs. Fortunately, the Wyrd4Sound DAC II has I2S connections so I could hear the Transient II’s I2S performance for myself. It was easily the best sound I heard from both the Transient II and the Wyred4Sound DAC II. The improvement was principally in dimensionality. Not only did the front-to-back depth increase, all the instruments and voices gained additional solidity and edge definition. It was a lot like going from a very good solid-state power amplifier to a tube amp; the 2-D image morphed into 3-D. I used a PS Audio Perfect Wave 12-1 I2S cable for the connection. I also tried a generic HDMI cable, and while it, too, was superior to the S/PDIF connection, the imaging improvements were far less obvious. When I switched back to the Wryed4Sound’s own built-in USB implementation and compared it with the Transient II’s S/PDIF output, the dimensional presentations from the same USB source were virtually identical.
As a stand-alone USB DAC/Pre the Transient II gets high marks. If you can get by with one pair of single-ended RCA outputs the Transient II can serve as the center of your computer audio system. I was impressed by the Transient II’s lack of electronic edginess. Especially on voices, such as Emma Kirkby’s delicate soprano on the live concert album Time Stands Still [Hyperion], the lack of grain and glare lets the music flow with relative dynamic freedom. Unlike some budget gear, which sounds clean yet sterile, the Transient II’s overall presentation had an ambience and bloom that were natural and relaxed, without the slow, thick sound of some vintage tube gear.
Listening to my own DSD-format live concert recording of the Boulder Philharmonic performing Brahms’ Double Concerto in A minor for violin and cello played back through Audirvana Plus’ real-time DSD-to-PCM converter at 176/24, I was most impressed by the Transient’s ability to preserve all the subtle spatial details that were present in the recording. The violin and cello soloists were so clearly defined in space that when the violinist turned his body, even slightly while playing, it was immediately obvious. The Transient also did an excellent job of retaining all its sonic virtues even on double-forte passages— the sound didn’t get harder or more aggressive during dynamic peaks.
Near the end of the review period Channel Islands sent me its $329 VDC-5 Mk II high-current power supply. While I didn’t detect any improvement or sonic changes in the S/PDIF or I2S streams when I installed the VDC-5 Mk II, I did hear an improvement in the quality of the Transient II’s analog outputs. Dynamic contrast improved with greater image stability and focus. According to Dusty Vawter, whether the VDC-5 Mk II makes a sonic difference will depend on a number of factors, such as the noise generated by your computer’s video card and the noise on the USB connection. With some portable computers running on their battery supply the VDC -5 Mk II will make no sonic improvements. But if you run them plugged into AC, the VDC-5 Mk II will reduce the noise coming from the USB power supply. Given the VDC-5 Mk II’s cost, I would strongly suggest trying it out on your own system since it may not be the most cost-effective upgrade for the Transient II, especially if you are using the Transient II primarily as a USB-to-S/PDIF bridge. If you have an I2S-compliant DAC I would recommend investing in a high-quality HDMI-type cable before springing for the VDC-5 Mk II power-supply upgrade.
MY TRANSIENT RESPONSE
To say I was impressed by the Transient II’s combination of modest price and excellent sonics is something of an understatement. If you are contemplating spending $700 or more for a USB-to-S/PDIF converter, you should consider the Channel Islands Audio Transient II. For a reasonable price it lets you keep up with the current state of USB 2.0-compliant audio, even if your DAC lacks USB capabilities. And while we wait for the next wave of products with USB 3.0 compliance, the Transient II will keep your music flowing beautifully.
LINDEMANN USB-DAC 24/192 CONVERTER AND DAC ($1100)
The second DAC in this survey comes from Lindeman. Although in business for more than twenty years, Lindemann is a relative newcomer to the United States. Now distributed by One World Audio, this German company, formed by Norbert Lindemann, opened its doors in 1992. In 1999 Lindemann introduced the first upsampling CD player, and in 2002 the first German- manufactured SACD player. Releasing leading-edge digital products is nothing new for Lindemann, and its latest USB DAC is no exception.
Understatement in physical design is a hallmark of Lindeman products. The Lindeman USB DAC is a small 11⁄2″ by 43⁄4″ by 5″ silver-tone box with a single circular push-button on the front. The rear panel has inputs for USB, TosLink, and S/PDIF, one pair of RCA single-ended outputs, and a power-supply connection. That’s it. The only user adjustment is the source-selector button on the front. And while the Lindemann USB-DAC 24/192 may appear, at least from the outside, to be a modest entry-level offering, inside it’s packed with Lindemann’s current thinking on state-of-the-art digital technology. The USB interface is based on the XMOS DSP chip, and offers asynchronous “bit-transparent” resolution up to 192/24. The digital interface controller is the Wolfson WM8805, and the DAC chipset is the Wolfson WM8742. According to Lindemann’s published specifications, the USB DAC 24/192’s internal master clock produces less than 2.5 picoseconds of timing errors. The USB 24/192 also uses a “minimum phase” digital filter with an “apodizing” filter to reduce phase, timing, and group-delay issues.
For jitter reduction the 24/192 features an active jitter- reduction scheme that employs a digital PLL (phase locked loop) and memory buffering of the digital stream. According to Lindemann, “The remaining jitter of the signal (not the clock!) is below 50 picoseconds.”
Although the analog outputs are single-ended RCA, the Lindemann DAC employs a fully balanced analog output stage with bandwidth that extends up to 200MHz. According to Lindemann, “As a result of the silicon-germanium technology used for the wafer, the module’s supply voltage is limited to 5V. The result of this is an optimal output voltage of 1.4V RMS for 0dBFS. Consequently, the USB-DAC 24/192 is quieter than competitors using standard operational amplifiers.” As you would expect from a USB 2.0-compliant device, no additional drivers or plug-ins are needed for Mac use. For Windows machines Lindemann offers a certified driver and installation instructions.
SETUP AND ERGONOMICS
Given its level of internal sophistication, the installation, setup, and day-to-day operation of the USB DAC 24/192 were disarmingly simple. Once a USB cable was attached between the Lindemann and my Mac, the DAC was recognized in the Sound Control Panel as “Lindemann USB 2.0 Audio,” and I could select it as my output device. Although the Lindemann has no volume controls, its volume can be adjusted in software via iTunes (or other playback software). Since its full level is only 1.4 volts, and many fixed-output devices use 2.0 volts as their standard single- ended output level, in some installations such as those that use a passive preamp with no provisions for gain, the Lindemann might not have sufficient maximum volume. But in other systems this lower output level could allow users to employ the Lindemann without a preamp, using only minimal software gain attenuation. Another option for potential users searching for a minimalist solution could be attaching the Lindemann directly to a pair of powered speakers with gain controls, such as the Adam Artist 5x or PSI A-14M powered monitors.
The USB DAC 24/192 doesn’t come with a remote, but chances are you’ll never miss it. The only pushbutton on the front panel controls the input source, and if you have only one source, such as when the Lindemann is hooked up to your computer’s USB, even that button will remain untouched.
Unlike many USB DACs, which offer the option of a digital output, the Lindemann has only analog outputs, so it can’t be used as a USB-to-S/PDIF converter. While this may limit its appeal to some audiophiles looking for a USB converter as well as a DAC, it does keep things simple—it’s the analog out or nothing.
THE LINDEMANN SOUND
From the first time I heard the USB DAC 24/192 at CES I thought it was a very fine-sounding DAC. My experiences with the 24/192 at Casa Stone have done nothing to change this opinion. With a musical yet revealing character, the USB DAC 24/192 produces a large and well-defined three-dimensional soundstage that sounds neither digital nor analog—on good recordings it sounds like a microphone feed.
Early in the review I tethered the USB DAC 24/192 analog outputs to the April Music Eximus DP-1 DAC/PRE. This setup let me compare the Lindemann’s analog output to that of the Eximus DP-1. Since their USB interfaces are based on the same XMOS chipset I wasn’t exactly shocked to find that the two USB/ DAC sections had very similar sonic signatures when the Eximus DAC was set to 192/24 oversampling mode. The Eximus DP-1 delivered slightly better low-level resolution and dimensionality, but it had the advantage of one less interconnect in the signal chain. Both DACs also had a very similar harmonic balance and dynamic contrast when the DP-1 was in 192/24 mode.
When the DP-1 was set to non-oversampling native-rate processing the Lindemann USB DAC 24/192 sounded tighter with less harmonic bloom, but with more detail and low-level information. The fact that the differences between the Eximus DP-1’s three processing modes were greater than the differences between the Lindeman USB DAC 24/192 and the Eximus DP-1 in 192/24 processing mode tells you how similar to each other these two DACs can sound.
Putting an $1100 DAC against a $3500 one would not be considered a fair fight under most circumstances, but to give you an idea of how well the Lindemann DAC performs, that is its competition. The April Music DP-1 DAC PRE has a lot more ergonomic flexibility with its excellent built-in headphone amp, pure analog pass-throughs, and high-quality analog volume control, but based solely on sonic performance the Lindemann USB DAC 24/192 is certainly on the DP-1’s level.
Since many users will also be hooking up an S/PDIF source to the Lindemann USB DAC 24/192, I spent time listening to music through the S/PDIF input. To supply the S/PDIF I used the Human Audio Tabla converter ($995), which utilizes the M2Tech HiFace as the basis for its USB conversion. With its built-in battery power supply and automatic charging via USB, the Tabla doesn’t complicate the computer-audio grounding scheme, thereby reducing the chance of ground loops affecting the sound quality. Using the Tabla also let me compare the Lindemann’s XMOS USB solution with Human Audio’s M2Tech HiFace.
On Alexis Harte’s song, “Please Come Out” from his Six Spoons of Honey album, the similarities between the Human Audio USB interface and the Lindemann USB DAC 24/192 were far greater than the differences. Both created equally large, well- focused, and three-dimensional soundstages. After more than a half hour of going back and forth, the primary difference I heard between the two USB solutions was ever-so-slightly better solidity and fine detail through the Human Audio Tabla USB interface.
On my live concert recording of the Boulder Philharmonic performance of Ruby Fulton’s “Deadlock,” the sonic differences between the two USB interfaces were miniscule. During the beat-box solo passages I was impressed by the Lindemann DAC’s harmonic neutrality and the analog section’s transparency. Together they did a superb job of accurately rendering the dimensionality and dynamics of the live-to-DSD recorded performance.
If you like simple ergonomics coupled with high performance, the Lindemann USB DAC 24/192 may be what you’ve been looking for. Connect a USB, S/PDIF, or TosLink input and get superb music from its single-ended RCA analog outputs. What’s not to like? Well, it might not be a stand-alone unit, since you could need a preamp or volume attenuation method if you aren’t using software to control volume. Also with its 1.4V maximum fixed output, passive preamp systems might lack sufficient gain to drive your system to full volume levels. But if you use the USB DAC 24/192 with an active preamp its output level won’t be a problem, and if audio quality is your primary purchase criteria you’ll be hard-pressed to find a DAC that convincingly beats it.
NUFORCE DAC-100 DAC/PREAMP ($1095)
NuForce’s emphasis on high performance at a moderate price has, in a few short years, transformed the brand from “Who dat?” to “Oh, them!” The NuForce DAC-100 marks its first foray into the product category of DAC/preamps. With a feature set that should work equally well in a computer desktop/ headphone system or a small-room computer-based system the NuForce DAC-100 packs a lot of features and technology into its svelte chassis.
Although it is part of NuForce’s home/desktop product line instead of its reference line, the DAC-100 is sonically and ergonomically a high-value product through and through. What you don’t get, and don’t have to pay for, is a fancy case, thick front panel, or elaborate chassis. The DAC-100’s dimensions are 9.5″ by 8″ by 2″ high, putting it in a 3⁄4-width size category. And while it doesn’t take up much space, it does produce some heat, so giving it adequate ventilation, both below and above, is important for optimal operation.
NuForce calls the DAC-100 a DAC/preamp, which means it performs the functions of a DAC and a preamp. As a preamp the DAC-100 only supports digital sources. It has four inputs— USB 2.0, TosLink, and two S/PDIF RCA digital. For outputs the DAC-100 includes one pair of single-ended variable-output RCA connectors and a headphone jack on the front panel. The DAC- 100’s headphone output is designed to support headphones with an impedance range from 120 to 600 ohms, so it may not be suited for all headphones, especially high-sensitivity low- impedance in-ear models.
The front panel of the DAC-100 contains a rotating volume knob, three bit-rate indicator lights, four input buttons, and a headphone jack. The volume knob also doubles as a standby switch by pushing it inwards. On the back panel are all the inputs and outputs, and the standard IEC AC connector. The DAC- 100 comes with a credit-card sized remote that supports basic functions including on/off, volume level, input selection, and the all-important mute button.
Installation was simple: I merely plugged in a USB cable between the DAC-100 and my MacPro desktop computer and the Mac recognized the NuForce in the Sound Control Panel Attachment as “Nuforce 192k DAC—HS.” For PCs you can download the newest driver from NuForce’s Web site. I used the DAC-100 with a variety of Mac playback software including iTunes, Pure Music, Amarra, Audirvana Plus, Decibel, Fidelia, and Audacity with no compatibility issues.
One thing you can’t do with the DAC-100 is use it as a USB converter since it lacks any kind of digital output. If you plan to use it in conjunction with NuForce’s new DDA-100 digital integrated amplifier, the DAC-100 will be getting a digital feed from the DDA-100 via a TosLink connection, and since the DDA-100 will power the main speakers, the DAC-100 will be relegated to headphone-amplifier duties.
Since the DAC-100 only has one pair of line-level RCA outputs, using it in a system that has a subwoofer requires a wee bit of McGyvering. You can either attach Y-connectors to the RCA outputs on the back of the DAC-100 to give you two line- level feeds, or you can use the headphone output on the front panel. Most of the DAC/PREs I’ve reviewed, such as the April Music Eximus DP-1, mute their line-level output when you plug in headphones to their front panel, but the DAC-100 does not. Because both of the DAC-100 outputs are active and their volume levels are controlled by the same knob, you have a readily available source for the subwoofer feed; all you’ll need is a 1⁄4″ stereo-to-female-stereo RCA adapter.
For most of the review the DAC-100 was connected directly to a pair of PSI A-14M powered monitors and a Velodyne DD+10 subwoofer (using the Y-connector scheme), but near the end I used it with NuForce’s DDA-100 ($549) direct-digital integrated amplifier, an Accuphase P-300 power amplifier, and a Parasound A-23 attached to several of my reference desktop speakers, including the Role Audio Canoe, Aerial Acoustics 5B, Silverline Minuet, and ATC SC-7 speakers.
The only ergonomic issue I experienced with the DAC-100 was with its volume knob. It felt slightly loose and sloppy. Also it doesn’t take very much pressure to push the knob in, muting the DAC-100, which may not have been your intention when you reached for the knob. I much prefer the volume knob on NuForce’s DDA-100, which looks and feels better.
If you look inside the DAC-100 you’ll find a very sophisticated audio instrument. With a 32-bit digital volume control instead of the more-common 24-bit variety, a single-ended 500-milliwatt headphone amplifier, and a non-upsampling 192/24 DAC, the DAC-100 delivers excellent published specifications for jitter, frequency response, and THD+N, as you can see on NuForce’s site.
THE NUFORCE SOUND
The NuForce sound, or should I say lack of it, came as a pleasant surprise. I installed the DAC-100 just after reviewing the Lindemann USB 24/192 DAC. The first A/B comparison test I performed was with these two DACs running into the analog inputs of the April Music Eximus DP-1 DAC/PRE. After critically matching the output levels I was flummoxed to discover that I couldn’t reliably identify one from the other. Both did a superb job of preserving all the subtle soundstage cues and both had equally expansive soundstages. Since they are priced within $5 of each other, if I were forced to choose I would make my decision based on their ergonomics rather than sound quality. If I already had a good analog preamp I’d opt for the Lindemann, but if I didn’t own a preamp I’d chose the NuForce DAC-100.
Obviously the NuForce DAC-100 is sonically competitive with similarly priced DACs, but how does it rate verses higher-price DACS? I couldn’t do any real-time A/B switches, since testing involved disconnecting and reconnecting interconnects, but after several hours of listening I could reliably identify several sonic differences between the DAC-100 and the April Music Eximus DP-1. First the DP-1 had slightly better low-level detail. In my live DSD recording of The Deadly Gentlemen from Salina Schoolhouse, mandolinist Domenic Leslie turns to fiddle player Mike Barnett and says, “I’ll take the low part.” It’s easier to make out not only his words, but the direction he’s facing through the DP-1 than the DAC-100. Also the DAC-100’s soundstage is not quite as deep or three-dimensional as the DP-1. All the players seem to be closer to the wall behind them through the DAC-100.
To discover how good the DAC-100’s USB implementation was I set up another A/B test, this time with the Human Audio Tabla USB interface box. I attached the Human Audio Tabla’s S/PDIF output to one of the DAC-100’s two S/PDIF inputs and used Audirvana Plus for playback because it has the fastest switchover between output devices. Once levels were matched I found it impossible to tell which input I was using. While one test isn’t enough for me to state conclusively that the DAC-100’s USB implementation is equal to the
Tabla, I can confidently say that adding an external USB interface did nothing to improve the DAC-100’s performance.
I spent quite a bit of time, especially early in the morning while my wife was still sleeping in the bedroom right over my office, listening to the DAC-100’s headphone output. With some headphones, such as the Grado RS-1 and AKG K-701, the DAC-100 headphone output is dead quiet. But with other headphones, such as the
Audio-Technica ATH W-3000ANV or the Sol Tracks HD, I could hear a faint low-level hiss. Fortunately the hiss didn’t get louder as the volume increased, but higher sensitivity earphones are more likely to have some background hiss from the DAC- 100’s headphone outputs.
A NUFORCE IN USB DACS
$1000 to $1200 seems to be a price that many manufacturers are aiming at with their latest high-performance USB-enabled DACs. NuForce’s entry at this hotly contested price point delivers excellent sound combined with a useful feature set, making it one of the DACs that should be on anyone’s “must audition” short list, if he’s in the market for an under-$1500 USB DAC.
SYNERGISTIC RESEARCH MUSIC CABLE DAC ($3599)
It takes a certain amount of nerve (or cluelessness) to write that a $3500 DAC with cables and a built-in power conditioner is a “value proposition.” But that’s exactly what the Synergistic Research Music Cable was designed to be. Synergistic Research practically gives you a 192/24-bit DAC for free with some of its very tricked-out cable. If you add up the cost for a 1-meter length of terminated Synergistic Research Active digital cable ($1000) and a 1-meter length of Synergistic Research Active Tungsten interconnects ($2000), a Powercell ($1250), Galeleo universal interconnect cells ($1500), and Precision A/C Basik power cord ($250), it comes to $6000, and that doesn’t even include a DAC. By anybody’s standards, getting $6000+ worth of stuff for only $3599 is a bargain.
THE SOUP-TO-NUTS SOLUTION
Setting up the Synergistic Research Music cable can be as simple as plugging one end into a digital source’s S/PDIF output and the other end into the analog inputs on your preamp. The Music Cable supports up to 192/24 data streams and will automatically detect and set its DAC for the proper data transfer. BNC devotees will be happy to discover that the Music Cable comes with a BNC termination. If your transport or media server uses RCA hardware for its S/PDIF output, you will need to use a BNC-to-RCA S/PDIF adapter.
There are no adjustments on the Music Cable except for a pair of interchangeable Galileo universal interconnect cells. These cells come in three varieties, black, grey and silver, and are designed to affect the overall balance of the system. Synergistic Research, or its dealers, can make suggestions as to which of the cells would be best for a particular system, but Synergistic Research encourages owners to try all three to determine their own preferences. My preference during the review varied more based on program material than basic system balance. Since switching the cells takes less than five seconds, using them as overall harmonic balance controls is about as easy as turning a knob or changing a low-hanging lightbulb.
I used the Music Cable DAC in a variety of computer-desktop and room-based systems. For computer use I needed to employ a USB-to-S/PDIF converter since the Music Cable accepts only S/PDIF. I used the Human Audio Tabla ($995) as well as the Empirical Audio Off-Ramp 5 converter box when I employed USB sources. Synergistic Research makes a similarly priced USB- only version of the Music Cable, but it only supports up to 48/16 data files. And while I found its performance on Red Book and MP3s on a par with the S/PDIF version connected to the Tabla, (that was the conversion box I used for the A/B), its lack of support for higher bit-rates makes it less of a future-proof high- value purchase than the S/PDIF version.
During the review I only came across one compatibility issue. When connected to my MacPro system the Music Cable produced a low-level, but audible, hum at normal listening levels, on the right channel only. By repositioning the Music Cable I could lower the hum level, but I could never get the unit far enough away from whatever in the system that was causing the hum to eliminate it completely. None of my other computer- or room-based systems produced a similar problem. In every other system the Music Cable was dead quiet.
THE SYNERGISTIC SOUND
For a good part of the review period the Music Cable DAC was connected to a stock Logitech Touch music server. I also used the Music Cable coupled to a Lexicon RT-10 universal transport, Oppo BDP-95 universal player, and Meridian 598 DVD/CD transport. Since the Music Cable can only support one input I suspect that most users will want to hook it up to a music server or computer-audio source (for this a USB/SPDIF converter box may be needed) for maximum ergonomic ease.
The first A/B test I conducted after almost a month of break-in time was with the Wyred4Sound DAC II. Since the Logitech Touch has two digital outputs I could use the S/PDIF for the Synergistic Research Music Cable DAC and the TosLink connected to the Wyred4Sound DAC II. Obviously this wasn’t a completely fair test since the Wyred4Sound was saddled with a higher-jitter TosLink connection, but because the Music Cable won’t accept TosLink it was my only option. At least both DACs had the same Synergistic Research Active Tungsten interconnects between the DACs and my Parasound P-7 preamp. For those who think comparing a $3600 DAC to a $1500 one isn’t a fair comparison, remember that with the $2000 Synergistic Research interconnect the Wyred4Sound combo comes to just under $3500.
Hooked up to the Squeezebox Touch the Synergistic Research Music Cable produced a noticeably more three-dimensional image than the Wyred4 Sound DAC II. Both DACs delivered equal amounts of detail, but the Music Cable’s increased dimensionality located small details more incisively within the soundstage. Harmonic balance differences were miniscule, with the Music Cable delivering a slightly more relaxed and less mechanical presentation.
To see how much the source quality had to do with the sonic differences I heard, I did additional listening tests using the Lexicon RT-10 transport. Once more the Music Cable got the S/ PDIF output, but this time the Wyred4Sound got an AES/EBU signal feed. Based on my tests when I reviewed the RT-10 many moons ago, the AES/EBU was the RT-10’s best-quality digital output. Once more the Music Cable produced its usual remarkably three-dimensional soundstage. But unlike the first test, here the Wyred4Sound’s soundstage wasn’t left as far behind—in fact on some material such as the MA recordings Wolfgang Amadeus Mozart—Works from His Golden Age—Yoko Kaneko: Fortepiano I was unable to distinguish between the two DACs in matched-level tests. As a control I also listened to the analog output from the RT-10. After I reduced its output to match the two DACs output levels I was surprised to find how close it came in performance. Only in depth recreation did the Music Cable deliver noticeably superior results. On another MA Recordings release, Nima Ben David—Resonance, all three conveyed the same excellent transient response and immediacy of Ben David’s viola de gamba. But the Music Cable preserved the best sense of depth and room bloom. The Wyred4Sound DAC II made the room seem slightly smaller, as if the back wall had been moved forward by ten or fifteen feet. The Lexicon RT-10 had the least depth, but wasn’t too far behind the Wyred4Sound DAC II.
On some material I couldn’t hear any discernable sonic differences between the Synergistic Research Research Music Cable and the Wyred4Sound DAC II—specifically Kelly Joe Phelps’ Brother Sinner & the Whale. Both DACs did a superb job of capturing the grit in Kelly Joe’s voice without adding any electronic grain or grit to the sound. Both also preserved the subtle dynamic nuances of Kelly Joe’s fingerpicked resonator- style acoustic guitar. Finally, both DACS provided an equal number of spatial cues and the same degree of precise lateral focus.
For a third round of A/B CD-source tests I used my own live concert recordings of the Boulder Philharmonic, down-sampled from DSD to a Red Book 44.1/16 CDR. Once more the Music Cable displayed the best spatial reproduction. The soloists in the Brahms Double Concerto for Violin and Cello were more firmly anchored in space and had a greater feeling of solidity and mass through the Music Cable than from the Wyred4Sound DAC II.
For my last listening tests I went back to the Squeezebox Touch, but with higher-resolution 96/24 and 192/24 music files (yes, the Squeezebox Touch supports 192/24 with the addition of a third-party app, available directly from the Squeezebox’s own internal menus). I used the same Boulder Philharmonic recording, but this time it was only down-sampled to 96/24 and 192/24. Again the Synergistic Research Music Cable created a more convincing and dimensional soundstage. On the Frank Zappa composition, “Be-Bop Tango,” recorded in 2010, the Music Cable’s superior depth recreation was readily apparent, especially during the contrapuntal final passages when the music became rock-n-roll frenzied.
For 192/24 sources A/B comparisons I had to do a manual disconnect, and reconnect the S/PDIF cables from the back of the Squeezebox Touch because the TosLink connection doesn’t support 192 (96k limit). While this was less than ideal due to the lag-time during the changeovers, I still found that the Synergistic Research Music Cable DAC had slightly better depth recreation. The difference was not as pronounced as when the Wyred4Sound was getting a TosLink feed, but it was still noticeable.
IS A MUSIC CABLE IN YOUR FUTURE?
If you’ve read this far, obviously you’re interested in the Synergistic Research Music Cable. And despite its ergonomic limitations, with only one non-switchable input, no volume adjustments, single-ended-only analog outputs, and five separate fairly stiff cables to manipulate in an orderly manner, the Music Cable’s sonic performance sets it apart from any “convenience” DAC I’ve heard.
As I wrote earlier, I can easily see the Synergistic Research Music Cable DAC attached to a music server to form the front end of an ultra-modern high-performance music-reproduction system. Even coupled to the modestly priced Logitech Squeezebox Touch the Synergistic Research Music Cable produces a level of audio quality that emphatically checks all the audiophile boxes in double-black magic marker. If you want to keep it simple and high-end, the Synergistic Research Music Cable DAC may be all you really need.
SPECS & PRICING
CHANNEL ISLANDS AUDIO TRANSIENT II
Digital outputs: S/PDIF via 75-ohm BNC connector (galvanic isolated), i2s via mini-din connector (Audio Alchemy/Perpetual Tech/Camelot), differential i2s via HDMI connector (PS Audio/Wyred4Sound)
Sample rates supported: 44.1k, 48k, 88.2k, 96k, 176.4k, 192k up to 24 bits
Analog output Level: 2V RMS maximum (single-ended RCA)
Dimensions: 4.45″ x 2.9″ x 5.25″
Shipping Weight: 5 lbs.
Warranty: Five year parts & labor
CHANNEL ISLANDS AUDIO
567 W. Channel Islands Blvd.
PMB #300Port Hueneme, CA 93041
LINDEMANN USB-DAC 24/192
Inputs: USB-B, TosLink, coaxial
Supported sampling rates: 32kHz to 192kHz (USB 2.0, TosLink, coaxial)
Output voltage: 1.4V at full scale
Dimensions: 4.7″ x 1.77″ x 5.23″
Weight: 395 gm
Warranty: Three years
ONE WORLD AUDIO (U.S. DISTRIBUTOR)
Inputs: USB, TosLink RCA (x2)
Sampling rates supported: Up to 192kHz
Outputs: RCA, 6.3mm headphone jack
Recommended headphone impedance: 120-600 ohms
Headphone output level: 10.4V p-p, 3.7V RMS at 300-600 ohms
Dimensions: 8.5″ x 2″ x 9″
Weight: 2.64 lbs.
382 South Abbot Ave.
Milpitas, CA 95035
SYNERGISTIC RESEARCH MUSIC CABLE
No specs provided
17401 Armstrong Ave., Suite 102
Irvine, CA 92614