Bel Canto Design – REF Link USB Converter
Fulfilling The Promise of Digital Playback
Living in Minneapolis, Minnesota has provided me with access to many wonderful music related activities that help feed my insatiable appetite for the real thing (i.e., live music). In particular, the Twin Cities is host to a number of top-notch music venues that provide a regular dose of wonderful live performances, featuring a variety of music types. One of my favorite hangouts also happens to be one of the finest jazz joints in the country. It is known as The Dakota Jazz Club. This club not only provides a steady stream of both, traditional and contemporary jazz but also more recently has expanded into hosting artists covering Pop, R&B, world music and various other interesting performances. The artists range from some of the best known in the recording industry to those who are relatively new and emerging talent on the jazz scene.
The Twin Cities is also home to a number of well-known and highly respected high-end audio manufacturers. Again, my appetite for accessing this type of equipment is fed by this reality. This includes the likes of Audio Research Corp., Bel Canto Design, Magnepan, Atmasphere, Van Alstine and various others. Not bad for a quiet Midwest city that is often mischaracterized as the “Frozen Tundra” but also a city that provides a vibrant and economically diverse business community with a nice complement of Fortune 1000 companies headquartered here. Bottom line, the relative ease of getting around the Twin Cities ensures fairly easy access to the various high-end audio manufacturers mentioned above. For me, this has been an unexpected blessing.
Additionally, my audio journey has been long and fruitful with a progression from tubed electronics and analog playback equipment to solid-state and digital playback. Yes, there are those days when my mind drifts back to the so-called “Golden Era”, where black vinyl ruled, but as I also try be as open-minded as possible and focused more on the future, I must admit that current digital technology definitely seems to have picked up steam and is progressing aggressively. In fact, computer-based audio is rapidly upon us and anyone denying its presence is likely stuck in the past and wishing not to be a part of this exciting change.
My point in mentioning this is to simply compare and contrast what I am now experiencing, and specifically as I am now migrating to an enhanced level of digital playback as my sole music source. My initial exposure was like many of yours, a basic one-box CD player. Later I experienced a separate CD transport along and external DAC as the way to go. This approach introduced additional cabling (i.e., digital link and power cords) that added costs. What I thought would be the basic plug and play approach has now been disrupted with the emergence of new technology taking digital playback to a much higher standard of sonic quality.
TRANSITIONING FROM GOOD TO GREAT DIGITAL PLAYBACK
Again, I had the distinct advantage of having easy access to local manufacturers and hands-on technical support. In this instance, my conversion from using a more traditional approach of CD transport coupled to an external DAC was swift and convenient. Having the designer of the specific product for this review available to assist with installation made the change a snap. In a visit to my home, John Stronczer, head engineering guru at Bel Canto Design, quickly inserted a laptop (PC), as the music server, along with the Bel Canto Design REF Link (USB converter). Size-wise, this unit is shaped/styled very similar to other electronics in the Bel Canto line and takes up minimal space. The front panel sports a knob that allows the user to switch the display from off to the bit-rate. Additionally, there is an illuminated screen indicating when the unit is locked at 44.1 and ready to stream digital. On the back of the unit there is an AES/EBU output as well as a BNC SPDIF and glass optical connection (AT&T), USB connection, on/off switch and receptacle for an AC power cord.
For the review, the REF Link was connected to the laptop via a USB cable with the output signal being fed to my Bel Canto DAC 3.5 VBS via AT&T ST glass fiber-optic cable. This arrangement was particularly convenient since I was able to locate the laptop on an equipment stand near the listening position and run a 30’ long glass fiber optic cable to my DAC with no loss or signal degradation. Additionally, JRiver Media Center software was already installed on the laptop so it was simply a matter of minutes before I was streaming digital for music playback. One other nice feature was the ability to synch my iPad Mini with the JRiver software and Wi-Fi in my home. As a result, I am able to use it as my remote. Essentially, this approach enables the user to see all recordings that are on the laptop and make a selection from this unit.
Even though I had heard the REF Link at the Bel Canto Design factory, I really wasn’t quite sure what to expect in my system. Needless to say I was anxious, and at the same time excited, with the prospect of improving the sound of my system. Well my friends, I have some good news and I have some bad news. First, the good news; by having this change made in my reference system, the difference and level of improvement were so immediately noticeable that I could only shake my head in appreciation. As for the bad news, I soon I was faced with a rather perplexing situation that specifically focused on what I now had to do with my very competent CD player/transport/digital cable combo. After listening to a variety of recordings with the new setup, my current digital playback rig no longer seemed relevant.
In order to make sure I wasn’t simply allowing myself to be fooled into hearing what I wanted (or had hoped) to hear, I switched back from the computer/USB converter generated playback to my original reference. Same DAC and interconnects were used to control those as variables. Without question, the newer playback system was the clear winner and not by a slight margin. Essentially, it was a game changer and I was totally ready to make the switch. Beyond that, I quickly invited several golden-ear audiophile friends over for a listen and literally the very same reaction occurred with them as well.
So just exactly how did the Bel Canto REF Link USB converter improve the sound of music in my system? Instantly my system sounded even quieter than before with music emerging from a very black background. Music emerged with a very natural, lifelike quality with enhanced dynamics across the entire soundstage. Macro and micro dynamics became that much more tangible with leading edge transient attack being sharper and more precise. Trailing edge transients simply shimmered with very clean, clear articulation allowing the sound to naturally fade away. Additionally, there was a more organic feel to the music with improved body and texture. Beyond this, there was improved clarity and openness as well. Subtle musical details that had been obscured previously became much more obvious, clear and distinct. Instruments rocked but the midrange also took on added dimensions of layering and body as well.
An excellent example of how really good music can be enhanced was by listening to Manu Katche’s very creative recording titled Neighbourhood [ECM]. The rendering of musical instruments along with the spatial qualities of the soundstage are captured in a very magical way. Another great recording is Ray Brown’s Soular Energy [Concord]. On this recording played via the REF Link, Ray’s superb playing of the acoustic bass becomes all that much more impressive. Additionally, Gene Harris’ masterful piano playing on this recording can be even more fully realized as well. With the increased clarity and open quality to the sound – I was able to more fully discern the tonal characteristic of these instruments making everything sound more real and lifelike. Similar reaction when listening to Ahmad Jamal’s recording titled Blue Moon [Jazz Village]. The attack of the piano was rendered in a very authoritative manner with clear distinct dynamic thrust so very obvious. Additionally, Herlin Riley’s performance on drums during this recording is totally outstanding and with the added clarity and impact through the REF Link – the sound is outstanding and totally convincing. For vocals, whether female or male, single performer or groups – the enhanced tonal and spatial quality of the sound with the REF Link in place was elevated to a significant level.
Overall, it was as if the proverbial veil had been lifted thus allowing me to more easily listen and hear deeply into the music. Soundstage width, depth and height all improved as well as notes within the soundstage taking on more body with a greater tactile sense as well as becoming more dimensional. Here’s the other really good news; with the enhanced lifelike quality to the music, I was not aware of any negative aspects to these improvements. Any concern about the music becoming forward and in your face was quickly dispelled. Instead, image placement on the stage became more focused with greater solidity and coherence. Again, it was all good.
Every day there seems to be new and innovative USB converters appearing on the scene - some inexpensive and others not so - and with lots of hype about their overall ability to improve digital playback performance. Sorting through the options may be a bit daunting but perhaps also necessary. The Bel Canto Design REF Link USB converter is a highly effective product capable of significantly improving digital playback in a high-end audio system. It has quickly and easily helped me more fully appreciate just how good digital playback can be. My previous setup was no slouch but with the Bel Canto Ref Link – there is far greater realism and authenticity to the music.
What this unit does is shocking and transformative. Fortunately, by high-end audiophile standards, this product is also reasonably affordable and provides a very strong price to performance ratio. The return on investment is definitely there. But what really counts is the music and this product helps make wonderfully beautiful music. Once you hear what it does, I am confident you will not be able to go back. For me, my experience with the Bel Canto Design Ref Link has been totally positive and nothing short of revelatory. It’s a keeper. Highly recommended and definitely is a candidate for a “Most Wanted Component 2013!” award.
INTERVIEW WITH JOHN STRONCZER: DESIGN APPROACH – TECHNICAL OVERVIEW
Because of my lack of being particularly techno savvy and not wishing to try to impress the readers otherwise, I (BW) decided to put a series of questions to John Stronczer (JS), the designer, for an even better understanding of this particular product and its impact on the music. Below are a series of questions, and responses, for this review in hopes that this information will provide insights regarding his innovative design to achieve higher levels of digital playback. Here goes:
BW: What inspired you to develop the Link series of USB converters and specifically the REF Link?
JS: These designs grew from the exploration of the potential offered by Asynchronous operation. This operating mode allows us to actually remove any jitter on the audio waveform-allowing a low noise free-running oscillator of our choice to define jitter on the audio signal. There is no control loop in the system to add jitter to the critical oscillator- having a free running oscillator is so important to the ultimate performance that can be achieved. Our experiments with better and better oscillators and cleaner power supply environments naturally led to the 3 tiers of products represented by the mLink, uLink and REFLink. Our listening tests showed a clear improvement with each step.
BW: What are the key technologies that you've employed in this unit that provide such improvement in signal processing for enhanced sonic reproduction?
JS: The designs utilize a 500MHz DSP core that is common to all three Link products. This core provides the Asynchronous operation, telling the computer when to send data at a rate that is governed by our low noise reference oscillator. This technology is followed by our low noise oscillator and retiming circuitry, all powered by low noise power supplies. The REFLink goes further by offering another layer of galvanic isolation with internal power for all stages for an even better controlled and lower noise environment. The uLink and REFLink both use the Ultra-Low Phase Noise clocks with only 70 femtoseconds (0.07 picoseconds!) of integrated jitter from 100Hz to 1MHz.
BW: What are the specific undesirable things about digital that you've addressed with the REF Link?
JS: It is remarkable how much of the grain, edge and dynamic compression of the audio signal are due to noise on the critical digital clock. When we finally are able to strip this noise away using the technologies in our Links the sound of digital playback becomes very organic, dynamic and involving-much as good analog from top LP playback and tape sources achieve as a matter of course.
BW: Why is it better to rip CDs to a storage device such as a hard drive (i.e., lap top), or some other medium such as this vs. directly playing back from a CD?
JS: The CD playback mechanism is fundamentally a mechanical process with numerous motors operating and generating noise and interference signals at audio frequencies.-These noise signals can easily modulate the clock and show up as jitter on the digital output. This noise can result in muddied sound with layers of harshness. Playing back from a computer allows the computer to store the audio data into local computer memory and clock the data out-running this through a USB Link further isolates the critical clock from being corrupted by the playback hardware-especially in the case of the REFLink with its highly optimized architecture. Further benefits from computer playback accrue when you factor in high res file options-now we are getting into master tape quality performance-although it is remarkable how good 16/44.1 files can indeed sound!
BW: Is the REF Link your ultimate approach for a USB converter or are there other cost-no-object approaches you envision developing at some time?
JS: The REFLink architecture forms the basis for new developments that promise even further evolutionary gains and remains our ultimate approach to a USB Link product.
BW: What affect do USB cables make when downloading signals from a lap top? Can improvements in overall sonic performance be realized by using various types of exotic high-end USB cables with the REF Link? Please explain.
JS: With the REFLink I have not found the USB cable to have as much influence but certainly the mLink and uLink can benefit from better cables as the USB cable is part of the power supply for these units. The isolation provided by the REFLink architecture mitigates the impact from the USB cable-of course this does not necessarily eliminate cable quality from influencing playback.
BW: Please explain why you chose ST fiber as the preferred cable choice for the REF Link? How does this differ from the various types of coax cables with SPDIF connections and what are the benefits sonically?
JS: ST fiber can operate with very wide bandwidth; it is specified for use up to 160 MB/s over lengths of 1 kilometer. In audio we are using less than 10% of this bandwidth thus preventing any added jitter on the signal due to bandwidth limitations. By their nature, Optical Interconnects have additional advantages including no radiated electrical noise, no sensitivity to electrical noise and complete galvanic isolation between the send and receive ends.Further advantage relates to the ability to run long distances with no signal degradation-including up to 100 meters can easily be run.Also even relatively low cost ST fiber offers these performance advantages.
Controls and Indicators
On/Off power switch
Sample Rate LEDs indicating 44.1, 48, 88.2, 96, 176.4 and 192 Ks/s
Input: High Speed USB type-B receptacle
Coaxial SPDIF on BNC 75Ω
Balanced AES on XLR 110Ω
LightLink ST Fiber
Supported sampling rates:
Supported word lengths: up to 24-bit
Native MAC USB 2.0 compatible on OSX 10.6 and later
Custom Windows USB 2.0 driver Win 7 and XP
Driver appears as Bel Canto uLinkUSB2.0 select as default playback
System volume control is disabled upon installation
BNC/RCA adapter included
USB cable not included
Power Usage On: 3W
Power Usage Off: 0.0W
Power Requirement : 120VAC/60Hz or 240VAC/50Hz set internally
Dimensions: 8.5” W x12.5” D x 3.5” H (216mm x 318mm x 88mm)
Weight : 14lbs (6.5kg)
REFLink Core Technology
Proprietary 500MHz DSP Asynchronous USB Core
Dual Ultra-Low Phase-Noise Clocks
Two-stage galvanic isolation
Dedicated LNS (Low Noise Supply)
Full e.One chassis and front-panel display
Native MAC USB2.0 Compatible
Retail Price: $1495.00
Name: Bel Canto Design, Ltd
Designer: John Stronczer
Address: 221 North 1st Street, Suite 300
Minneapolis, MN. 55401
Tel: (952) 317-4551
Web Site: www.belcantodesign.com