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    Berkeley Audio Design Alpha USB Review

    alpha-usb-front-200x63.pngThe Berkeley Audio Design<sup>®</sup> Alpha USB<sup>®</sup> converter was one of the most highly anticipated computer audio products of 2011. Fueling the anticipation were several delays during development and initial production. Many computer audiophiles wondered what Berkeley Audio Design was doing since early 2010 when rumors of the product started circulating. During that time the perfectionists at Berkeley Audio Design fine tuned the Alpha USB using unique design approaches, the best measuring techniques available, and extensive listening sessions. Shortly before production began Berkeley Audio Design rejected critical components from suppliers for quality unbecoming of a true reference converter. Following many months of research and development 'Berkeley' wasn't about to rush the Alpha USB to market. Fortunately good things come to those who wait. Sonically the Alpha USB is extremely impressive. After four months using the Alpha USB, in combination with the Alpha DAC<sup>®</sup> Series 2, I'm continually astonished by its level of performance. In fact, the Alpha USB is so good I've yet to hear a better digital interface. Period.

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    <center><img src="http://images.computeraudiophile.com/graphics/2012/0303/alpha-usb-front-584x187.png"></img></center>

     

    <b>The Alpha USB Interface</b>

     

    The Alpha USB from Berkeley Audio Design is an external asynchronous USB to AES or S/PDIF interface. It's strictly a D to D converter accepting USB digital audio input and delivering AES or S/PDIF digital audio output. Because humans can't hear digital signals a Digital to Analog Converter (DAC) is also required to reproduce music in one's home. A simple audio playback flow chart consists of a PC -> Alpha USB -> DAC -> Preamplifier -> Amplifier -> Speakers. Such an interface can play a critical role in presenting the cleanest audio signal to a DAC or may be necessary in order to use a DAC without a next generation interface such as USB or FireWire. Plenty of wonderful DACs without USB or FireWire interfaces are as good or better than new DACs with interfaces for every source imaginable. When users find a sound they like there is no need to change. Fortunately these users can add a device like the Alpha USB to extend the life of their already great digital to analog converter.

     

    There are a couple competing schools of thought when it comes to the best place for a USB interface. Just as in everyday life, there is no free lunch with either design approach. One school advocates for the USB interface to exist within the digital to analog converter. This allows the DAC chip to receive data using its native I<sup>2</sup>S protocol. In theory this design is capable of lower jitter if implemented without an intermediate conversion to S/PDIF before I<sup>2</sup>S. This USB implementation can also incorporate such methods as opto-isolators and grounding to isolate an internal USB interface from the sensitive DAC circuitry. The other school of thought insists USB interfaces must be completely separate from the chassis of the DAC. Physical separation allows for an otherwise unobtainable level of isolation between the noisy computing environment and the delicate digital audio environment. This isolation eliminates any direct electrical connection to the DAC's chassis and is required to reach the highest levels of USB audio performance according to proponents of the separate chassis design. In addition these proponents believe the benefits of a direct I<sup>2</sup>S data path are not worth the tradeoffs of reduced isolation and increased noise from a single chassis design. Needless to say Berkeley Audio Design believes strongly in separating the USB interface from the chassis of the DAC.

     

    No matter what USB interface school of thought is most appealing one mustn't hyper focus on this single element of component design. Each design element or internal part selection only equates to a certain level of potential. Reaching that potential is what separates the armchair engineers and the component assemblers from the truly brilliant designers. The bottom line is not about numbers and theories. It's about the component as a whole being much more than the sum of its parts and the sound it helps reproduce in one's audio system.

     

     

    <b>Separating The Alpha USB From The Pack</b>

     

    The Alpha USB's retail price of $1,895 is the most readily visible item that distinguishes it from much of the competition. This interface is expensive and that fact is not lost on Berkeley Audio Design. The company is intent on producing products with great value. As such the wholesale margin on the Alpha USB is lower than the Alpha DAC which is already one of the lowest in the industry. Berkeley Audio Design is a humble, down to Earth company. Trust me these guys won't be retiring to a private island with the spoils collected from Alpha USB and Alpha DAC sales. The fact remains that it's expensive to build components that achieve the highest levels of performance. The Alpha USB is no exception.

     

    The Alpha USB is all about clocking and isolation. This sounds fairly straight forward at first blush. Upon closer inspection and research it appears the Alpha USB is in a class all by itself. The Alpha USB employs clocking components that weren't available prior to its development and isolation techniques that may be unique in all of high end audio. Now comes the part where I, and every journalist, grow frustrated. Because of the highly competitive nature of consumer electronics and the value placed on intellectual property, manufacturers are unwilling to divulge too many technical details in public. This is a fact of life. Fortunately consumers have the option of listening to the end product to decide if any of the public or private details really matter. In my conversations with Berkeley Audio Design's Michael Ritter I was able to glean some details worth noting.

     

    Design work on the Alpha USB began in 2009. At that time the clocking components used in the final production version of the Alpha USB weren't available. Berkeley Audio Design knew it wanted to use dual fixed crystal oscillators that performed to a certain level not seen in any digital audio interface product. Thus, 'Berkeley' was involved in co-developing new oscillators not yet commercially available. New computer audiophiles should understand that crystal oscillators are used to generate the clock signals for 44.1, 88.2, 176.4 kHz and 48, 96, 192 kHz audio. These components are critical to accurate sound reproduction. The entire Alpha USB development process was fraught with delays and less than desirable results. After rejecting early components from the vendor, "Everything just came together." said Michael Ritter. The final production version of the Alpha USB contains dual fixed oscillators. One for each sample rate family of 44.1, 88.2, 176.4 kHz and 48, 96, 192 kHz. Only a single oscillator is operational at a time. Even very good low jitter oscillators can produce relatively high levels of low frequency phase noise. Not so inside the Alpha USB. I was unable to obtain actual numbers for these specific oscillators, but I talked to an engineer from a competing high end audio company who was familiar with the products in use by Berkeley Audio Design. He stated a couple times that the low phase noise from these oscillators was unique and remarkable.

     

    Adding to the Alpha USB's excellent clocking is the use of Streamlength<sup>™</sup> asynchronous USB code in conjunction with the XMOS USB receiving chip. Small companies such as Berkeley Audio Design need to leverage design talent. In this case there was no reason to reinvent the wheel. The Streamlength code was selected because it was already well developed and was very robust. Streamlength asynchronous USB code controls the data flow from the computer or music server and the newly developed crystal oscillators take control as the master clock generators. No matter what one believes about the importance, or lack thereof, of asynchronous USB and its oscillator design "requirements" it would be hard to second guess the Alpha USB's design approach.

     

    The Alpha USB's non-standard 2.3”H X 10.5”W x 5”D dimensions (2.55”H including feet) serve one purpose: function. According to Berkeley Audio Design the Alpha USB's unprecedented level of isolation can't be accomplished in a smaller chassis. "The unit is the size it has to be" says Michael Ritter. Mr. Ritter explained that the unique isolation techniques used in the Alpha USB are very difficult to implement and theorized that this difficulty is a major reason nobody else in high end audio has gone to this level. I gathered that many isolation design choices are like a balloon in that pushing in on one side causes the opposite side to stick out. Reduce the measured numbers in one area and increase the numbers in another as a result. All engineers have dealt with similar phenomena in other design endeavors. Michael Ritter hinted that tracing secondary and tertiary coupling paths in addition to minimizing capacitive coupling by surrounding the USB input connector with an inch of plastic were just a few of the isolation elements addressed. The inch of plastic on the rear of the chassis is one item I noticed as being unaesthetic the first time I saw the Alpha USB. It's good to know the Alpha USB's form entirely follows function and there's a good reason for every design decision.

     

    Another major contributing factor to isolation is how the USB interface is powered. Berkeley Audio Design elected to power the USB receiving chip in the Alpha USB via USB bus power from the computer. Power emanating from the computer's USB port doesn't traverse any further than the USB receiving chip inside the Alpha USB. 'Berkeley' uses its proprietary isolation techniques that are said to provide much better performance than traditional opto-isolation methods while keeping computer generated noise away from the sensitive output clocking and driver circuitry. Powering the audio output side of the Alpha USB is a low noise linear power supply. This noise filtered linear supply feeds clean power to the oscillators and the digital audio output circuitry.

     

    On the rear of the Alpha USB are two outputs; balanced AES (XLR) and coaxial S/PDIF (BNC), and an output selection switch. Many devices with more than one digital output keep all the outputs live continuously no matter what output is in use. According to Berkeley Audio Design the highest levels of performance simply cannot be reached without deactivating the unused output(s). Thus, the reason for the Alpha USB output selection switch. The user must toggle either the balanced AES or the coaxial S/PDIF output on/off.

     

    Berkeley Audio Design strongly recommends using the balanced AES output of the Alpha USB when possible. In theory a true coaxial 75 ohm S/PDIF connection is better, all things being equal. However, all things are not equal in practice. Given that balanced AES does not use true 110 ohm connectors I inquired into this recommendation a bit further. The answer I received from Michael Ritter was mainly voltage, and some noise rejection. Even though S/PDIF when implemented with 75 ohm BNC connectors is a true 75 ohm coaxial connection its limitation is that it delivers .5 volts peak to peak. Balanced AES on the other hand benefits from a 2 to 7 volt signal amplitude. In fact the Alpha USB's AES output delivers 4 volts or eight times the signal level of the S/PDIF output. This higher voltage is key to maximizing data receiver performance and reducing effective jitter. The balanced AES connection also offers common mode noise rejection. In addition to recommending the balanced AES output Berkeley Audio Design also recommends using a 1.5 meter AES cable and USB cable when possible. This recommendation has everything to do with reflected versus original digital signal energy caused by return loss. A cable and its connectors is not a perfect transmission line as it suffers from reflected energy. When a 1.5 meter cable, 3 meters round trip internally, is used this reflected energy is delayed enough to minimize confusion with the original signal at the data receiver. These may be small or insignificant details to some, but are important and critical details for those seeking the highest level audio reproduction.

     

    All of the aforementioned design elements including oscillators, isolation, asynchronous USB transfer mode, USB bus power, and linear power are only equivalent to potential. Data sheets and application notes for each internal component contain nothing for designers seeking to push the boundaries of what's possible. A brilliant engineer and a holistic design approach are required to master the interaction between all the potentially excellent internal components. All of this must come together to produce an excellent product such as the Alpha USB.

    <center><img src="http://images.computeraudiophile.com/graphics/2012/0303/alpha-usb-rear-480x161.png"></img></center>

     

     

    <b>Where The Rubber Meets The Road</b>

     

    After all design and engineering is complete any product can still be a colossal failure if the sound quality doesn't meet expectations. The Alpha USB is far from a failure. Its unprecedented design is commensurate with its astounding sound quality. The Alpha USB has opened the door to use almost any DAC with any computer or music server source. The old formula of using a Lynx AES16 audio card in a desktop computer to feed an AES signal to my Alpha DAC now seems antiquated and mid-fi at best. The Alpha USB works flawlessly with desktops and laptops running Windows, OS X, and Linux. It also works perfectly in combination with the Aurender S10 and SOtM sMS-1000 Music Servers. All sample rates from 44.1 kHz through 192 kHz are supported on all platforms. Because Windows does not support Class 2 audio, users are required to install the supplied device driver for proper operation. The driver in use today is the same driver I received when the unit was first delivered to my house. This is a good sign that the driver is stable and developed by people who know what they are doing. The same can't be said for all USB device drivers used in other products.

     

    The Alpha USB paired with the Alpha DAC Series 2 is possibly the best digital I've heard in my listening room. At the time of this writing the Alpha USB alone is the best external audio interface I've heard anywhere bar none. During the extended four month review period I used the Alpha USB with numerous sources and DACs from many different manufacturers. The standard AES and S/PDIF digital outputs on the Alpha USB make it compatible with almost any DAC. Even the BNC output can be connected to a coaxial RCA input through the use of an adapter. I compared the Alpha USB to a few different D to D converters I had on hand between November 2011 and early March 2012. Most of the compared interfaces were fairly inexpensive ranging from around $200 to $500 with one interface retailing for near $1,000. The results were unambiguous. Only the $1,000 interface came close to the performance of the Alpha USB. However, close isn't good enough for those of us seeking the ultimate interface.

     

    The Alpha USB provided an immaculate digital audio stream to my Alpha DAC Series 2. The result was incredible detail and extremely controlled bass. This was very evident listening to both Ray LaMontagne's Are We Really Through [<a href="http://www.amazon.com/God-Willin-Creek-Dont-Rise/dp/B003QCCS36/ref=sr_1_3?ie=UTF8&qid=1330804650&sr=8-3">Link</a><a href="http://www.amazon.com/God-Willin-Creek-Dont-Rise/dp/B003QCCS36/ref=sr_1_3?ie=UTF8&qid=1330804650&sr=8-3"><img src="http://images.computeraudiophile.com/ca/icons/ex.png" style="padding: 0pt 0pt 0pt 3pt;" alt="link"></img></a>] and the Kansas City Symphony's performance of Passacaglia at 24 bit / 176.4 kHz [<a href="http://www.referencerecordings.com/HRx120_DETAIL.asp">Link</a><a href="http://www.referencerecordings.com/HRx120_DETAIL.asp"><img src="http://images.computeraudiophile.com/ca/icons/ex.png" style="padding: 0pt 0pt 0pt 3pt;" alt="link"></img></a>]. The detail I heard in Ray LaMontagne's voice made me giggle. When something is so good I tend to respond in abnormal ways. I was almost in disbelief because of the incredible breathy detail. Changing styles with the Kansas City Symphony I was again thrilled by what I heard. I've used Passacaglia (track #6) many times to evaluate components and I've never heard more detail or better controlled bass from my system. The entire 7:16 track is full of low level detail and wonderfully powerful bass. Less patient readers may want to jump ahead to the 4 minute and 25 second mark for a minute and a half of serious dynamics that will test the quality of any component. Don't get me wrong, this is not an audiophile demonstration disc. I simply love this recording more every time I listen.

     

    Over the course of four months I listened to a fair bit of music. A few recordings played through the Alpha USB really grabbed my attention. Ottmar Liebert's One Guitar at 24 bit / 96 kHz [<a href="https://www.hdtracks.com/index.php?file=catalogdetail&valbum_code=HD783707392707">Link</a><a href="https://www.hdtracks.com/index.php?file=catalogdetail&valbum_code=HD783707392707"><img src="http://images.computeraudiophile.com/ca/icons/ex.png" style="padding: 0pt 0pt 0pt 3pt;" alt="link"></img></a>] can really demonstrate the sound of an unamplified acoustic guitar. If I were a guitar player I'm sure I could identify the strings and model of guitar he used on this album simply by listening. Near the end of the review period I started listening to the newly released Leonard Cohen album Old Ideas [<a href="http://www.amazon.com/Old-Ideas-Leonard-Cohen/dp/B0067LY4WG/ref=sr_1_1?s=music&ie=UTF8&qid=1330804987&sr=1-1">Link</a><a href="http://www.amazon.com/Old-Ideas-Leonard-Cohen/dp/B0067LY4WG/ref=sr_1_1?s=music&ie=UTF8&qid=1330804987&sr=1-1"><img src="http://images.computeraudiophile.com/ca/icons/ex.png" style="padding: 0pt 0pt 0pt 3pt;" alt="link"></img></a>] and a Blu-ray rip of Leonard's Songs From The Road at 24 bit / 96 kHz [<a href="http://www.amazon.com/Songs-Road-Blu-ray-Leonard-Cohen/dp/B003VSVWAA/ref=pd_sim_m_35">Link</a><a href="http://www.amazon.com/Songs-Road-Blu-ray-Leonard-Cohen/dp/B003VSVWAA/ref=pd_sim_m_35"><img src="http://images.computeraudiophile.com/ca/icons/ex.png" style="padding: 0pt 0pt 0pt 3pt;" alt="link"></img></a>] (both albums Mastered by Doug Sax and Robert Hadley at <a href="http://www.themasteringlab.com/">The Mastering Lab</a><a href="http://www.themasteringlab.com/"><img src="http://images.computeraudiophile.com/ca/icons/ex.png" style="padding: 0pt 0pt 0pt 3pt;" alt="link"></img></a>). Leonard's 77 year old baritone has wonderful texture on both albums but more so on Old Ideas. Using the Alpha USB this texture was palpable. The tones of his voice and the bass guitar weren't smeared in the least as can happen with less refined digital interfaces. I felt like Leonard was singing / talking right in my ear. Either that or the microphone used to record him was placed directly in front of his larynx.

     

     

    <b>Conclusion</b>

     

    <a href="http://images.computeraudiophile.com/ca/cash-logo-black.png" class="thickbox" rel="cash-alpha-usb"><img src="http://images.computeraudiophile.com/ca/cash-logo-black-thumb.jpg" style="padding: 2pt 10pt 5pt 0pt;" align="left" alt="CASH-List"></a>Slow and steady wins the race and good things come to those who wait. Alpha USB design work started in 2009, before some components used in the final product existed. Production units began shipping in September 2011. The many months in between were filled with more R&D than many high end audio products. During this time Berkeley Audio Design participated in development of highly accurate oscillators with incredibly low phase noise. In addition 'Berkeley' mastered the balancing act required when using the unprecedented methods of isolation found in the Alpha USB. All of this isolation, clocking accuracy, and low noise design means nothing without proportional sonic performance. Fortunately the Alpha USB was well worth the wait. As it stands now I know of no better digital interface converter. The sonic purity heard through the Alpha USB is something to behold. In fact there is no way I'm giving up the review sample. This level of design and sound quality comes at a price above that which most people are willing to spend. Audiophiles prepared to part with $1,895 will no doubt be delighted with the Alpha USB connected to any source or any DAC. The Alpha USB has solidified my view that a reference level digital interface will play a critical role in achieving all that computer audio can deliver.

     

     

     

     

     

     

     

     

     

     

     

     

     

    <b>Product Information</b>:

    <ul>

    <li>Product - Berkeley Audio Design Alpha USB</li>

    <li>Price - $1,895 (black only)</li>

    <li>Product Page - <a href="http://www.berkeleyaudiodesign.com/products4.html'>http://www.berkeleyaudiodesign.com/products4.html">Link</a><a href="http://www.berkeleyaudiodesign.com/products4.html'>http://www.berkeleyaudiodesign.com/products4.html"><img src="http://images.computeraudiophile.com/ca/icons/ex.png" style="padding: 0pt 0pt 0pt 3pt;" alt="link"></img></a></li>

    <li>Where To Buy - <a href="http://www.berkeleyaudiodesign.com/us_sales.html'>http://www.berkeleyaudiodesign.com/us_sales.html">For U.S. Customers</a><a href="http://www.berkeleyaudiodesign.com/us_sales.html'>http://www.berkeleyaudiodesign.com/us_sales.html"><img src="http://images.computeraudiophile.com/ca/icons/ex.png" style="padding: 0pt 0pt 0pt 3pt;" alt="link"></img></a> | <a href="http://www.berkeleyaudiodesign.com/world_sales.html'>http://www.berkeleyaudiodesign.com/world_sales.html">For International Customers</a><a href="http://www.berkeleyaudiodesign.com/world_sales.html'>http://www.berkeleyaudiodesign.com/world_sales.html"><img src="http://images.computeraudiophile.com/ca/icons/ex.png" style="padding: 0pt 0pt 0pt 3pt;" alt="link"></img></a></li>

    <li>User Guide - <a href="http://files.computeraudiophile.com/2012/0303/Alpha_USB_User_Guide_v1_1.pdf">Link (PDF)</a><a href="http://files.computeraudiophile.com/2012/0303/Alpha_USB_User_Guide_v1_1.pdf"><img src="http://images.computeraudiophile.com/ca/icons/ex.png" style="padding: 0pt 0pt 0pt 3pt;" alt="link"></img></a></li>

    <li>Data Sheet - <a href="http://files.computeraudiophile.com/2012/0303/Alpha_USB_Preliminary_Data_Sheet.pdf">Link (PDF)</a><a href="http://files.computeraudiophile.com/2012/0303/Alpha_USB_Preliminary_Data_Sheet.pdf"><img src="http://images.computeraudiophile.com/ca/icons/ex.png" style="padding: 0pt 0pt 0pt 3pt;" alt="link"></img></a></li>

    </ul>

     

     

     

     

    <b>Associated Equipment</b>:

    <ul>

    <li>Source: <a href="http://www.aurender.com/">Aurender S10</a>, <a href="http://www.computeraudiophile.com/content/Computer-Audiophile-Pocket-Server-CAPS-v20">C.A.P.S. v2.0 Server</a>, <a href="http://www.apple.com/macbookpro/">MacBook Pro</a>, <a href="http://www.sotm.sonore.us/">SOtM sMS-1000</a></li>

    <li>DAC: <a href="http://www.berkeleyaudiodesign.com/">Berkeley Audio Design Alpha DAC Series 2</a>, <a href="http://www.dcsltd.co.uk/product/debussy-dac"><i>dCS</i> Debussy</a></li>

    <li>Preamp: <a href="http://www.spectralaudio.com/">Spectral Audio DMC-30SS Series 2</a></li>

    <li> Amplifier: <a href="http://www.spectralaudio.com/">Spectral Audio DMA-260</a></li>

    <li>Loudspeakers: <a href="http://tad-labs.com/en/consumer/cr1/">TAD Labs CR1 Compact Reference</a></li>

    <li>Remote Control Software: <a href="http://itunes.apple.com/us/app/aurender/id426081239?mt=8">Aurender iPad App</a>, <a href="http://www.jremote.net/">JRemote</a>, <a href="http://www.katoemba.net/makesnosenseatall/mpad/">MPaD</a></li>

    <li>Remote Control Hardware: <a href="http://www.apple.com/iphone/">iPhone 4</a>, <a href="http://www.apple.com/ipad/">iPad</a></li>

    <li>Playback Software Windows 7: <a href="http://www.jriver.com/">J River Media Center 17</a></li>

    <li>Playback Software: <a href="http://www.apple.com/macosx/">Mac OS X 10.7.x</a>, <a href="http://www.channld.com/puremusic/">Pure Music</a></li>

    <li>Cables: <a href="http://www.spectralaudio.com/">Spectral Audio MH-770 Ultralinear CVTerminator Series II Loudspeaker Cable</a>, <a href="http://www.spectralaudio.com/">Spectral Audio MI-350 Ultralinear CVTerminator Series II Analog Interconnects (RCA)</a>, <a href="http://www.mogamicable.com/category/bulk/dig_interface/aes_ebu/">Mogami W3173 Heavy Duty AES 110 ?</a>, <a href="http://www.mitcables.com/available-in-stores/power-products/oracle-ziii.html">MIT Oracle ZIII Power Cables</a>, <a href="http://www.wireworldcable.com/products/107.html">Wire World Silver Starlight USB Cable</a>, <a href="http://www.audioquest.com">AudioQuest Diamond USB Cable</a>, <a href="http://www.kimber.com/products/interconnects/digital/usb/bbus/ag/">Kimber Kable B Bus Ag USB Cable</a>, <a href="http://www.wireworldcable.com/products/53.html">WireWorld Ultraviolet 5 S/PDIF Coax Cable (BNC)</a>, <a href="http://industrialcomponent.com/oem/mi1005.html">Baaske MI-1005 Ethernet Isolator</a>, <a href="http://store.microconnectors.com/servlet/-strse-NETWORKING/Categories">Micro Connectors Augmented Cat6A Ethernet Cable</a></li>

     

     

     

     

     

     

     

     

     




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    You would think all async converters would sound the same. Maddeningly, and for reasons I don't think anyone outside those who research this and design and sell products from it, they do not and the differences are often not subtle.<br />

    <br />

    Thanks<br />

    Bill

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    These Async converters are not just converting data from one format to another; they are establishing the clock system which the receiving DAC must work off of, and retrieving the data from the computer in a way such as to keep a buffer full so that the data can be clocked out to the S/PDIF or AES/EBU output.<br />

    <br />

    ALL of the considerations regarding clock jitter and stability are quite important to the overall system design and performance. It's no surprise at all that different designs sound different, even ones all running Gordon's code. My own experience mirrors the benefit of even just improved isolation and buffering on a conventional S/PDIF input driven from a computer- witness the benefit of having an Antelop DA inserted between the computer and original Berkeley Alpha DAC. <br />

    <br />

    My Alpha USB just arrived yesterday, and I look forward to setting it up this weekend and doing some comparisons, including against the built in USB connection in the NAD M51, and with the Alpha DAC, and against my favorite LIO-8.

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    Very good points Jon. Please let us know your thoughts on the Alpha USB once you spend some time with the unit. <br />

    <br />

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    Jon, as a fellow LIO-8 owner and former BADA owner I will be eager to hear the results of your comparison. <br />

    <br />

    I would echo your comments on the import of jitter, stability and isolation in an async converter. I realized immediate, significant SQ improvements when I used an Antelope DA with my BADA. I just don't get why I should need such a device upstream of a modern DAC. <br />

    <br />

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    Hi All:<br />

    I am planning to replace my Bryston BDA-1 DAC with a Berkeley Alpha DAC2 this summer. I currently have a Weiss INT202 that allows me to interface my MacBook Pro via firewire to the Bryston via a Kimber cable (orchid digital cable). I run Pure Music with an external 2 TB hard drive (stored AIFF, FLAC music files) connected via USB to the Mac. I writing to ask if anyone has come across a comparison of the Weiss Int202 vs the Berkeley USB interfaces in linking to the alpha DAC2? From a price standpoint, they are similar, however, Weiss is firewire and the Berkeley is USB. Just wondering if one of these offer any advantage (in performance, sonics) over the other?<br />

    Tom

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    I don't THINK so but I have not done an in depth comparison. I did hear the Wiess device once compared to a Stello into a Metrum DAC - and I thought it was better than the Stello. However the sounds I was able to get out of my Off-Ramp into the Metrum was clearly better. This was not a side by side comparison so its rather tentative but I would say its about the same league as the Wavelength and Berkeley and a bit above the Audiophellio.<br />

    <br />

    Thanks<br />

    Bill

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    <i>I also tested the Berkeley into a Metrum and the Bryston compared to a fully optioned Off-Ramp with other audiophiles on more than one occasion. </i><br />

    <br />

    Don't want to side track this thread. Oh wait a minute, it's beyond side tracked already. <br />

    <br />

    What did you think of the Metrum vs Bryton?<br />

    <br />

    The Metrum in general?<br />

    <br />

    You can PM me if you rather.<br />

    <br />

    Thanks buddy,<br />

    <br />

    RM

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    The Metrum is one of the best DAC's I know but you must feed it with something like the Berkeley, Off-Ramp etc. Its not as good as the best DAC's I have heard such as my reference PDX and the Playback Designs I have just purchased - but it far from shamed and some people prefer it.<br />

    <br />

    Thanks<br />

    Bill

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    Why a BNC connector? Most cables with this interface tend to be pricey. And DAC's with an AES/EBU balanced input usually cost thousands. I'm sure this is a nice piece, but there are other products that do pretty much the same for a lot less $$$. Hey, not all of us can afford dSC Scarlatti systems.<br />

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    So has anyone done a listening comparison between the Alpha USB and the Weiss int203 yet? Considering the pedigree and engineering talent of both manufacturers I'm leaning toward the int203 based on the technical advantage of Firewire over USB 2.0. Any additional thoughts on this?

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    <i>"I'm leaning toward the int203 based on the technical advantage of Firewire over USB 2.0"</i><br />

    <br />

    Hi nd4speed - What technical advantages are you thinking about?<br />

    <br />

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    Hi Chris,<br />

    I've been able to consistently observe differences in transfer speeds between Firewire and USB 2.0, with Firewire 400 being faster. I know this is attributable to real world bandwidth and perhaps latency differences, but it may also be indicative of architectural differences intrinsic between the two interface specifications. Differences like the fact that USB host incurs most of the overhead associated with the transfer, and that perhaps other factors that I can't substantiate but have heard about Firewire; that more of its implementation is "on-chip" (for lack of a better term) vs USB for example.<br />

    Whether this amounts to measurably less jitter is arguable, but it seems very plausible.<br />

    Any feedback you can provide is appreciated. Thanks.

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    "Whether this amounts to measurably less jitter is arguable, but it seems very plausible."<br />

    <br />

    I find that the above is not at all plausible when considering asynchronous USB receivers. In an asynchronous environment, nothing going on in the USB host will have any effect on the jitter at the output of the USB receiver.<br />

    <br />

    BTW, has anyone ever published an photo of the interior of the Alpha USB? I would be very interested to check out the interior layout, power supply(ies) and parts selection... <br />

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    First at our level (ie not being a digital engineer like say a guy such as Steve Nugent is) a number of effects such as RFI, common mode rejection, and spikes etc travelling down the USB cable are usually grouped under the heading of Jitter even though strictly speaking it isn't. Async does nothing to really help those other issues. This explains why async implementations can and do sound different as I have heard many times and why different bit perfect players can and do sound different into async Dac's<br />

    <br />

    Thanks<br />

    Bill

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    I am not denying that these things matter, I am just saying that they do not effect jitter-I should add: in a well implemented asynchronous interface. A well implemented interface will have masterclock oscillators implemented in such a way as they are not affected by anything on the computer side.<br />

    Yes, the computer (and software, and USB cable) still matters, why, I am not sure, but it is not becuase it effects jitter. Jitter can be measured, although not easily well measured, I have not seen anyone demonstrate jitter measurements effected by the computer side of things when using a really good async interface.

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    Would love a comparison with the (substantially cheaper) Musical Fidelity V-Link 192.

     

    I listened to the new V-link II a few days ago and was not impressed at all. I have their M1HPA Headphone amp and it is really good. But on hi res classical music that I know very well both from sessions and via other dacs I did not find the V-Link II very good .

    It failed to reproduce both percussion strings and space and decaying notes realistically in for example the 24/176.4 recording of Rachmaninov's Symphonic Dances and from Reference Recordings. And The strings on 2L's very realistic true Reference recording of a string orchestra In Folk Style ,string sound was a bit harsh and not very resolved and lacked both the warmth and clairity that I heard both live at the sessions and hear via my Hegel HD 20 Dac and HD 800 headphones.

    Maybe it sounds better via coax but the only connection the dealer had was via usb and it was not very good IMO.

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    Chris my apologies regarding my post complaining about lack of references . I missed your link to the Britten the first time I read this review!

    All I am asking now, is that you always use that and other similarly revealing material in future reviews.

    I listened to that recording and several other very realistic ones with a selection of dacs recently via both my trusted HD 800 Headphones and via a TAD REFERENCE speaker and amp system.

    It seems we are on the same page regarding true references after all.

    ps I will listen to the Berkeley asap.

    ps 2 Benjamin Britten was a great composer too IMO.

    All the best Chrille

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    I listened to the new V-link II a few days ago and was not impressed at all.... Maybe it sounds better via coax but the only connection the dealer had was via usb and it was not very good IMO.

     

    I'm missing something here. The V-Link is a USB-to-S/PDIF adapter, so there will always be a USB connection from the computer or other player into the V-Link. The connection from the V-Link out to the DAC can be either version of S/PDIF, coax or optical (usually Toslink). Did you mean the dealer did not have a coax cable available so the output from the V-Link to the DAC was optical? Or were you listening to a V-DAC, which is a DAC rather than a converter, being fed by a USB cable from the computer/player?

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    I listened to the new V-link II a few days ago and was not impressed at all. I have their M1HPA Headphone amp and it is really good. But on hi res classical music that I know very well both from sessions and via other dacs I did not find the V-Link II very good .

    It failed to reproduce both percussion strings and space and decaying notes realistically in for example the 24/176.4 recording of Rachmaninov's Symphonic Dances and from Reference Recordings. And The strings on 2L's very realistic true Reference recording of a string orchestra In Folk Style ,string sound was a bit harsh and not very resolved and lacked both the warmth and clairity that I heard both live at the sessions and hear via my Hegel HD 20 Dac and HD 800 headphones.

    Maybe it sounds better via coax but the only connection the dealer had was via usb and it was not very good IMO.

     

     

    Just so we're clear. Are you talking about the V-Link II or V-Link 192?

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    Hi Chris,

     

    Thanks for the interesting Berkeley Alpha USB review. I bought one on 3/30/2012. It's connected to an HP laptop (running Win7 64bit and JRMC17) and newest Benchmark DAC1 HDR using the S/PDIF digital coax connections. JRMC17 is set to WASAPI-Event Style as recommended in the Berkeley Alpha User Guide. The music library is on an external USB hard drive.

     

    Things are going well, except when I change between songs of different sampling rates (e.g., 16/44.1 kHz to 24/96 kHz) in JRMC17 suddenly there is no sound. The JRMC17 interface still shows that the song is playing.

     

    To fix this, I close JRMC17, unplug the USB cable from the PC, and then plug it back in. This works until the next time I change between songs with different sampling rates and the same problem occurs. JRMC17 and Win7 are recommended in the Berkeley User Guide and JRMC17 is capable of seamlessly switching between files of different sampling rates. Given your experience with the Alpha USB, have you heard of this issue or have a solution?

     

    The same sound problem occurs when switching between the JRMC17 and iTunes players on the same laptop even with songs with the same sampling rate. This is of less concern to me because I don’t switch between players very often.

     

    Thanks

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    Hi Chris,

     

    Thanks for the interesting Berkeley Alpha USB review. I bought one on 3/30/2012. It's connected to an HP laptop (running Win7 64bit and JRMC17) and newest Benchmark DAC1 HDR using the S/PDIF digital coax connections. JRMC17 is set to WASAPI-Event Style as recommended in the Berkeley Alpha User Guide. The music library is on an external USB hard drive.

     

    Things are going well, except when I change between songs of different sampling rates (e.g., 16/44.1 kHz to 24/96 kHz) in JRMC17 suddenly there is no sound. The JRMC17 interface still shows that the song is playing.

     

    To fix this, I close JRMC17, unplug the USB cable from the PC, and then plug it back in. This works until the next time I change between songs with different sampling rates and the same problem occurs. JRMC17 and Win7 are recommended in the Berkeley User Guide and JRMC17 is capable of seamlessly switching between files of different sampling rates. Given your experience with the Alpha USB, have you heard of this issue or have a solution?

     

    The same sound problem occurs when switching between the JRMC17 and iTunes players on the same laptop even with songs with the same sampling rate. This is of less concern to me because I don’t switch between players very often.

     

    Thanks

     

     

    Hi Phil C - Hmm this is a weird one. The Alpha USB switches sample rates flawless in my system. Have you followed my JRiver setup guide? Do you have the audio output going through Default Device instead of the Alpha? If you follow this article everything should work great -> http://www.computeraudiophile.com/content/436-JRiver-Media-Center-17-Detail

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    Hi Phil C - Hmm this is a weird one. The Alpha USB switches sample rates flawless in my system. Have you followed my JRiver setup guide? Do you have the audio output going through Default Device instead of the Alpha? If you follow this article everything should work great -> http://www.computeraudiophile.com/content/436-JRiver-Media-Center-17-Detail

     

    Hi Chris,

     

    Per your suggestion, I checked settings using your JRiver setup guide and found my setup is okay. I have heard back from Michael Ritter of Berkeley Audio Design and, as with you, he has not seen this problem either. He thinks it's most likely a computer software or hardware issue.

     

    While checking I noticed that the Wiin7 System Properties screen does not show that Win7 Service Pack 1 (SP1) is installed, even though I routinely use the Windows Update feature to keep up-to-date. So this is an inconsistency I am checking on. Maybe I will be able to install SP1 "manually" with a download from the Microsoft web site and this may solve the problem. Fingers crossed and hope springs eternal!

     

    You might be like me and enjoy a good computer "mystery" (as long as the solution is found). If I get things fixed, I'll be sure to let you know the solution to this curious mystery.

     

    Talk to you later, I'm turning on the PC, rolling up my sleeves, and I'm going in.....

     

    Phil C

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    Hi, Chris! Glad to see your comments on the BADA USB. Nice work, and thanks for digging in there.<br />

    <br />

    I don't think you've done with the companion piece with the Series 2 DAC, yet, have you? If not, let me request that you try and tease apart the contribution of the USB transport? Running the Alpha USB into both the Series 2 and into, say, a dCS Debussy (I think that'd have to be by BNC S/PDIF, wouldn't it?) or another DAC of similar "level" that also sports an on-board USB interface may help us get a handle on what the Alpha USB does, or doesn't, do for the DAC over and above what using an on-board USB receiver might do. <br />

    <br />

    I've found that the Alpha USB can certainly "level up" just about any DAC I've used it with, even on DACs that have explicit isolation and great oscillators. Not sure why that is as I'd think that adding in an additional translation into and out of S/PDIF would do bad things to the overall sound quality. There are DACs out there that take USB and translate into I2S, for example, instead of translating into S/PDIF first, yet again, every DAC I've tried it with, benefits. <br />

    <br />

    IME, the Alpha USB really helps the Berkeley DAC shine and I completely agree with you that the bass on the Series 2 DAC is one of it's comparative strengths. With the Alpha USB, the already very good bass on the Series 2 is far better (best I've heard out of that DAC). <br />

    <br />

    But you have access to, and way more familiarity with, more DACs than I, and more DACs of varying character. So I am curious, does the Alpha USB "add bass to" (improve the bass performance of) bass-light (or DACs that aren't necessarily known for their bass performance) DACs? What about "liquid DACs", that is DACs that really do mid range well like a tube DAC (LampizatOr or AMR DP-777), or an "airy DAC" like the dCS -- any contribution of the Alpha USB there to the (non-bass) character of those DACs?<br />

    <br />

    Thanks, Chris. Appreciate the comments and still loving the site 2.5 years in. ;-)

     

    Hi, long time lurker, first time poster here. I have recently upgraded from Berkeley Alpha DAC Series 1 to Series 2 and have posted some impressions here:

     

    AudiogoN Forums: Review: Berkeley Audio Design Alpha DAC Series 2 DA converter

     

    Regards,

    Eugene

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    Hello Chris,

     

    I've recently replaced my MF Vlink (24/96) with the BADA USB and also upgraded the 75 ohm and USB interconnects with Audioquest high end cables, both being 1 step down from their top products. Source is Sony Vaia PC using Audiogate software driving an Accuphase C2110 + DAC 30, Qol signal completion unit, Sanders Magtech and Magnepan Mini Maggies.

     

    There is little point using the BADA Alpha USB unless the cabling is also upgraded. Using high end audio cables on digital equipment is problematical as these are optimised for audio frequencies, DC to 20KHz, (< 30KHz) while digital signals are, at minimum, double that. (The higher the frequency, the greater the presence of HF artefacts, usually known as skin effects in the conductors).

     

    That said, putting the BADA Alpha DAC into the system made an obvious difference from the MF Vlink (24/96). I have a BADA Alpha DAC series 1 but due to space limitations etc, and the fact I can't readily discern a difference between the Alpha DAC and the Accuphase DAC30 in my system, it's in storage for the moment.

     

    That raises a new issue - the sound of any DAC - for it is a fact that the despite what the various digital circuits are designed around, the final output from any DAC is analog audio. So why would one DAC sound different from another - digital circuit topology or analog stage topology, or both? This raises the question of the Accuphase C2110/DAC30 combo sounds identical to the BADA Alpha DAC driving one of the line inputs of the Accuphase.

     

    In my case I would need to compare the Alpha DAC driving the QOL etc as a preamp vs the C2110/DAC30 driving the QOL.

     

    One thing is quite obvious from having experienced the hi-fi tendency from its beginnings, technological progression hasn't diminished the audiophile factor at all. If anything, it's increased it; yesterday we were obsessing over VTA's - today cable physics.

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    Hi Phil C - Hmm this is a weird one. The Alpha USB switches sample rates flawless in my system. Have you followed my JRiver setup guide? Do you have the audio output going through Default Device instead of the Alpha? If you follow this article everything should work great -> Computer Audiophile - JRiver Media Center 17 In Detail

     

    Hi Chris,

     

    The problem is solved. Let me walk you through events. I previously told you that I followed your advice about using your JRMC Setup Guide. More recently, I installed Win7 SP1 and upgraded from JRMC17 to 18, but this still didn't fix the problem. I was out of ideas and time passed as I just lived with the problem.

    Then, unrelated to looking for a solution, I purchased a USB 3.0 external HD and moved my music library from a USB 2.0 external HD to it. Arbitrarily, I connected the new HD to a different USB port (which is a shared USB/SATA port ) than the port that the old HD was connected. When I next played music in JRMC, the problem was solved; I can switch between songs of different resolutions without playback halting.

    What to make of this? Was changing from a USB 2.0 HD to a USB 3.0 HD the solution? Not likely. So, unless I have overlooked something, simply plugging into a different USB port connection did the trick. How can this be? One theory: It's all about timing. I've read that selecting a USB port that is less busy with interrupts can improve musical performance. So, maybe I luckily picked a port that helped with sensitive timing issues between software. One problem with this theory though is that if this were the case then a lot of other Berkeley Alpha USB/ Windows PC users would be complaining about a resolution switching problem and they aren't.

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