• Berkeley Audio Design Alpha USB Review

    The Berkeley Audio Design® Alpha USB® 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® 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.

     








    The Alpha USB Interface

    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 I2S protocol. In theory this design is capable of lower jitter if implemented without an intermediate conversion to S/PDIF before I2S. 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 I2S 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.
     

    Separating The Alpha USB From The Pack

    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 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.

     

    Where The Rubber Meets The Road

    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 [Linklink] and the Kansas City Symphony's performance of Passacaglia at 24 bit / 176.4 kHz [Linklink]. 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 [Linklink] 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 [Linklink] and a Blu-ray rip of Leonard's Songs From The Road at 24 bit / 96 kHz [Linklink] (both albums Mastered by Doug Sax and Robert Hadley at The Mastering Lablink). 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.


    Conclusion

    CASH-ListSlow 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.


     



     



     


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    Comments 152 Comments
    1. KarolG's Avatar
      KarolG -
      Hi,<br />
      <br />
      Thanks for the review!<br />
      <br />
      Does such interface isolate DAC from the music server good enough to make server specification not important?<br />
      I mean to buy such a device and then build media server without taking any care of the quality of the components (sound wise). I could make some $$$ savings on the server side and this would justify Alpha USB price.
    1. wdw's Avatar
      wdw -
      Hello Chris, thanks for your review. <br />
      Truly sounds like a wonderful component. I see from your equipment list that you are using Spectral Electronics and am wondering whether you are using the gain stage of the pre-amp with the Alpha DAC or the digital volume control of the DAC. <br />
      I recall Berkeley claiming that direct connection to the amplifier was the clearest signal but also suspect the Spectral gear is so good that this might not be the case. Spectral is on my wish list for new electronics.<br />
      Regards, Warren
    1. Julf's Avatar
      Julf -
      Would love a comparison with the (substantially cheaper) Musical Fidelity V-Link 192.
    1. roubaixpro's Avatar
      roubaixpro -
      Great through review Chris.<br />
      <br />
      I your review, you state that a simple audio playback flow chart consists of a PC -> Alpha USB -> DAC -> Preamplifier -> Amplifier -> Speakers. <br />
      <br />
      I am planning to replace my entire home theater / stereo system. Using your flow chart example, I am thinking of getting the Aurender S10 > BADA Alpha USB > Classe SSP-800 Pre Pro > Parasound Halo A51 amplifier > B&W 803Di speakers.<br />
      <br />
      In my flow chart above, you notice that I have omitted a standalone DAC. The Classe SSP-800 has its own high quality DAC built-in. My question to you is that can I omit buying the BADA Alpha DAC2 and just use the internal DAC in the SSP-800 and still get good sound?<br />
      <br />
      <br />
      <br />
    1. Part-Time Audiophile's Avatar
      Part-Time Audiophile -
      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. ;-)
    1. accwai's Avatar
      accwai -
      <cite>Does such interface isolate DAC from the music server good enough to make server specification not important?<br />
      I mean to buy such a device and then build media server without taking any care of the quality of the components (sound wise). I could make some $$$ savings on the server side</cite><br />
      <br />
      Same here. Specifically, I'm wondering if Chris has done comparison between feeding from CAPS v2 through the SOtM USB card vs from the motherboard USB port. First, the SOtM USB card accounts for a large chunk of the cost of the CAPS v2. But more importantly, it imposes a lot restrictions on the architecture of the server. For example, it also requires a PCI bus that some newer Atom motherboard don't have. And by getting rid of the separate USB card altogether, embedded system type boards like the Alix can now be used. This could really open up a world of possibilities...<br />
      <br />
      Andy
    1. Mark Powell's Avatar
      Mark Powell -
      That the isolation of any half-decent DAC is every bit as good as this Berkeley pair. And with a single box you avoid the SP/DIF conversion. Which, despite what Berkeley say, must be a 'good thing'.<br />
      <br />
      I have only one computer, have no requirement for a second one, so I am not willing to spend the time and money building, for example, a CAPS2. So I have to go by what others say.<br />
      <br />
      But I am beginning to think that once you have 'bit perfect' output, simple enough to achieve with any computer, OS, and software player, that given good isolation in the DAC, or in this instance converter plus DAC, the computer does not matter at all.
    1. pawel8's Avatar
      pawel8 -
      Chris <br />
      Thank you for for a great review(as usual).<br />
      I have both Alpha USB and Alpha Dac series 2 running via Aes/EBU and directly to Ayre amplifier using balanced cables(Audioquest).<br />
      I like the sound very much to the point that I sold my CLEARAUDIO Ovation turntable.<br />
      I spoke with Berkeley and they confirmed that digital cables should be 1.5 meter long.<br />
      Now questions:<br />
      1.What brand of Aes/EBU Mogami,Straightwire or others?<br />
      2.What brand of USB cable?<br />
      3.Have you compared Alpha Dac 2 to Debussy sound while using Alpha USB?<br />
      4.Dac 2 to amplifier or via separate preamplifier.<br />
      Paul
    1. Elberoth's Avatar
      Elberoth -
      Chris, thanks for your review. A nice read, as always. The downside is no real comparision to the COMPETING products.<br />
      <br />
      By competing I mean dCS U-Clock, Diverter HD and the Off-Ramp Turbo 4 (soon to be superceded by Turbo 5).<br />
      <br />
      I have already read a review where prefered someone preffered the (cheaper) Off Ramp Turbo 4 to Alpha USB ...
    1. MarkS's Avatar
      MarkS -
      Please post a link for:<br />
      <br />
      "I have already read a review where prefered someone preffered the (cheaper) Off Ramp Turbo 4 to Alpha USB "<br />
      <br />
    1. Elberoth's Avatar
      Elberoth -
      Here you go:<br />
      <br />
      http://www.stereo.net.au/forums/showthread.php/41477-Bryston-Berkeley-Alpha-And-Off-Ramp?highlight=alpha
    1. VandyMan's Avatar
      VandyMan -
      Thanks for this review. I'm sorry you chose not to name the competition you compared to, but it was a very interesting review none the less. I'd love to hear what you think of the Berkeley in comparison to the Offramp 5.
    1. Elberoth's Avatar
      Elberoth -
      AFAIK Off Ramp Turbo 5 is not out yet.
    1. Mike Gillespie's Avatar
      Mike Gillespie -
      Can someone help me out: are we talking optimal length of AES and USB cable of 1.5 meters or is that the minimum length. IE, I just got a 5 foot USB and a 6 foot AES. If I exchange those for 1.5 meters will I be optimizing anything?
    1. easternlethal's Avatar
      easternlethal -
      I don't understand. CA had this unit for four months and instead of comparing against other similar products, he uses that time to compare between different sources and DACs. <br />
      <br />
      Then, when it comes to comparing against other converters he uses units that cost half as much at most before concluding a) another unit which costs $1000 actually comes close, and b) he knows of no converter better than the Alpha USB. <br />
      <br />
      Firstly I think a lot of users would actually not mind paying nearly half the price of the Alpha USB for another product that comes close (despite what he says about close not being 'good enough'), secondly I am not surprised he thinks it's the best converter since he only compared it against cheaper products. Did he even compare against any products in the same or higher price range, like the sonicweld diverter? If he did then why didn't he mention it?<br />
      <br />
      Sorry but this is as faulty a review process as I ever seen.
    1. The Computer Audiophile's Avatar
      The Computer Audiophile -
      @wdw - <i>"I see from your equipment list that you are using Spectral Electronics and am wondering whether you are using the gain stage of the pre-amp with the Alpha DAC or the digital volume control of the DAC."</i><br />
      <br />
      Great question. I am using the gain stage of the Spectral DMC-30SS Series 2 preamp. I et the Alpha DAC digital volume to 54.<br />
      <br />
      &nbsp;<br />
      <br />
      @roubaixpro - <i>"My question to you is that can I omit buying the BADA Alpha DAC2 and just use the internal DAC in the SSP-800 and still get good sound?"</i><br />
      <br />
      You most certainly can get good sound with your proposed system. <br />
      <br />
      &nbsp;<br />
      <br />
      @Mark Powell - <i>"That the isolation of any half-decent DAC is every bit as good as this Berkeley pair. And with a single box you avoid the SP/DIF conversion. Which, despite what Berkeley say, must be a 'good thing'."</i><br />
      <br />
      I see your inner armchair engineer coming through once again. It appears that you are satisfied with mediocrity and not interested in pushing the boundaries of engineering. That's totally OK with me. As long as you're enjoying this wonderful hobby of ours that's all that matters. You are enjoying it right?<br />
      <br />
      &nbsp;<br />
      <br />
      @pawel8 - <i>"Now questions: 1.What brand of Aes/EBU Mogami,Straightwire or others? 2.What brand of USB cable? 3.Have you compared Alpha Dac 2 to Debussy sound while using Alpha USB? 4.Dac 2 to amplifier or via separate preamplifier."</i><br />
      <br />
      1. I have a few different AES cables here. The Mogami cable is a favorite of mine simply because of the price to performance ration I receive with it. Ultra inexpensive, non-pretentious, and good performance. I also use a custom made cable that comes from another industry. This AES cable isn't available to purchase but provides awesome performance. I am looking into other AES cables now that the Alpha USB has impressed me so much. All things being equal, I prefer to use cables that CA readers can purchase instead of vaporware.<br />
      2. Kimber, WireWorld, and AudioQuest.<br />
      3. Yes, but not in a head to head type of way. Both have very different sonic signatures.<br />
      4. Very dependent on the components. I use a Spectral DMC-30SS Series 2 preamp. I think it's one of the most transparent components in all of high end audio. And, the Spectral preamp mates well with my Spectral DMA-260 amplifier. Thus, I use the preamp gain stage. <br />
      <br />
      &nbsp;<br />
      <br />
      @Elberoth - <i>"I have already read a review where prefered someone preffered the (cheaper) Off Ramp Turbo 4 to Alpha USB"</i><br />
      <br />
      Excellent. I encourage everyone to read reviews from as may sources as possible. CA is a single data point among many. Not everyone likes the same components or the same sound. Reviews are similar to legal opinions. If you look hard enough you can find evidence completely contrary to any existing conclusion or finding. That's part of what makes this an exciting hobby. If we all liked the same components it would be pretty boring. <br />
      <br />
      &nbsp;<br />
      <br />
      @easternlethal - <i>"Review method leaves a lot to be desired. I don't understand. CA had this unit for four months and instead of comparing against other similar products, he uses that time to compare between different sources and DACs. Then, when it comes to comparing against other converters he uses units that cost half as much at most before concluding a) another unit which costs $1000 actually comes close, and b) he knows of no converter better than the Alpha USB. Firstly I think a lot of users would actually not mind paying nearly half the price of the Alpha USB for another product that comes close (despite what he says about close not being 'good enough'), secondly I am not surprised he thinks it's the best converter since he only compared it against cheaper products. Did he even compare against any products in the same or higher price range, like the sonicweld diverter? If he did then why didn't he mention it? Sorry but this is as faulty a review process as I ever seen.</i>"<br />
      <br />
      Thanks for the honest opinion. I should probably clear up a couple things that may help put us on the same page. Computer Audiophile is not like Consumer Reports. The reviews contained here are not scientific longitudinal studies using products that compete on price and performance. CA is not curing Cancer and doesn't submit articles for peer review prior to publication similar to the New England Journal of Medicine or the like. You may still think the review process is as faulty as you've ever seen but my process is probably different than many others. I take an organic approach to listening to components and comparing them to others on hand. My results are not to be interpreted as the final word on anything and not to be used as a rubber stamp for how a component will sound in any system other than mine. As such, comparing components in a head to head or shootout fashion is really a disservice to everyone despite what at first blush may seem like the ultimate in informative journalism. In reality these types of comparisons are used as <a href="http://en.wikipedia.org/wiki/Link_bait">link bait</a><a href="http://en.wikipedia.org/wiki/Link_bait"><img src="http://images.computeraudiophile.com/ca/icons/ex.png" style="padding: 0pt 0pt 0pt 3pt;" alt="link"></img></a>. Disagreements with my subjective analysis are a natural and healthy part of any publication. When a component is "close but not good enough" for those seeking the ultimate in performance I'm happy to say so. This is strictly an opinion, like all reviews on all websites since the beginning of time. What's not close enough for me might be the best some else has ever heard. In addition what is the best I've ever heard may be child's play for someone else. Not a big deal. I enjoy reading about different methodologies and the conclusions that follow. Also of note is the fact that I've heard many more converters in all types of systems all over the world than I mentioned in this review. When I state that I've never heard a converter better than the Alpha USB I am taking all my listening experience into account. When I say the Alpha USB is better than a specific component I compared during the review period that's also exactly what I mean. Two very different statements that again are only valid for me. Hopefully readers who've followed CA for awhile understand the way I write and the type of sound that I like. Also, I hope my integrity comes through as new and experienced readers peruse the site. <br />
      <br />
      Thanks again for being brutally honest. I accept all opinions as an attempt at constructive criticism. Hopefully we are on the same page now or at least within the same chapter regarding how this and other reviews on CA are completed.<br />
      <br />
      <br />
      <br />
      <br />
      <br />
      <br />
      <br />
    1. Mark Powell's Avatar
      Mark Powell -
      "Satisfied with mediocrity"<br />
      <br />
      If you think the Debussy, the McIntosh, and the Tannoys are mediocre you are of course entitled to your opinion.<br />
      <br />
      You may have noticed that I am 'trying harder'. As such I refrained from making one comment, but I will now make it.<br />
      <br />
      I suspect the real reason that Berkeley introduced the USB to SP/DIF converter is (1) they don't have to update their DAC by adding a USB interface to it, (2) They get to sell two boxes rather than one. That said, It is probably very good.<br />
      <br />
      Re 'armchair', the rest of us don't get to try all these fancy boxes fot free, and for several months.
    1. Mark Powell's Avatar
      Mark Powell -
      Yes, I am enjoying it. I probably would not have done it at all were it not for finding this site. And your Windows/JRiver guide has given me confidence that I have done it properly.<br />
      <br />
      It has revived my flagging interest in recorded music, but I enjoy some of the controversies here too.<br />
      <br />
      My new overpriced 'remote control' using JRemote is terrific. As a phone it is useless, as I find texting on a touch keyboard terrible. But I find that with all touch screens, not just the iPhone. But as I never intended to use it as a phone anyway I am very pleased.
    1. easternlethal's Avatar
      easternlethal -
      Okay you want us to treat your review as subjective opinion. That is fine. <br />
      <br />
      But you dissed the practice of comparing components and said they are a disservice on the one hand then on the other you say in the article "[Alpha DAC + USB] is possibly the best digital I've heard in my listening room". So what... proper comparisons are wrong, but incomplete impressions based on subjective opinions are okay. Is that the kind of style you want us to get accustomed to?<br />
      <br />
      Secondly you said to Mark Powell regarding avoiding spdif conversion that this means he is satisfied with mediocrity and not pushing the boundaries of engineering. Does this mean that developments in converting usb - spdif - i2s = pushing the boundaries of engineering, wheras developments in converting usb - i2s directly are not? I think XMOS and all the other DAC manufacturers and manufacturers of USB - I2s converters (such as Emprical Audio) would disagree. <br />
      <br />
      Here's another bit of honesty. BA developed the USB because their DAC has a SPDIF-I2S converter and they just wanted to make something else to sell that can improve the sound without overhauling this architecture . It has nothing to do with advanced engineering or even whether usb - spdif - i2s is the best method of getting data into the dac circuitry (I doubt whether BA themselves would know).
    1. The Computer Audiophile's Avatar
      The Computer Audiophile -
      Hi Mark - Very happy to read CA has had a positive influence on you (but a negative influence on your bank account). <br />
      <br />
      I don't consider your components mediocre. Just some of your thoughts about component design etc...<br />
      <br />
      I still can't believe you have an iPhone :~)<br />
      <br />
      P.S. Thanks for the follow-up comments. Have a great evening navigating your music collection on that beautiful touchscreen :~)