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The Audiophilleo 1 can take complete control of attenuation and in this case it’s best to feed it bit-perfect audio rather than data already dithered and noise-shaped by another device. Firstly one needs to verify the integrity of the bit stream coming from the computer or audio server software. Philip has developed special test files that can easily confirm if bit-perfect transfer is successful at each sampling rate and word depth. It’s quite easy to get bit-perfect data from Windows to take full advantage of everything Audiophilleo has to offer. All that’s required is to install one of the inexpensive but capable 3rd-party media players such as the J. River Media Center (JRMC). Just select the WASAPI (Windows Audio Systems API) or WASAPI event mode and the bits will roll out perfectly intact.


With OS X everything goes through iTunes and a little care is required to make sure that bit-perfect playback is actually enabled. You’ll want to bypass its internal dithered volume control and more importantly various sample rate conversion and equalization algorithms whose effect on the sound can be deleterious. With software upgrades or other configuration changes these non-bit-perfect features may sometimes be re-enabled unintentionally but it’s easy enough to change back if you watch out for this possibility. For the myriad DACs that don’t have attenuation controls, the joystick on the Audiophilleo 1 or a universal remote allows you to make fine 0.5dB adjustments down to -20dB, with 1dB steps thereafter all the way down to -72dB. These days many recordings are cranked up to rather high average levels and depending upon the gain of the amplifier full roar might be -18 or even -20dB. Reference Recordings reach realistically loud full-scale levels at around -10dB in my system but most other productions max out at 8 - 10dB lower which is unfortunate. Compression is reducing dynamic range considerably.


For DACs with attenuators, setting the Audiophilleo 1 to Direct mode—automatic when 0.0dB is displayed—passes bit-perfect data downstream to the DAC or other signal processor so one may use its controls instead. You make the call.


Listening to the sound of silence:
For those readers who for whatever reason skip the preliminaries and head straight to the listening notes section, don’t listen to me but try the device yourself with your favorite music and make up your own mind. Then come back and compare my observations with yours. That way you’ll learn a lot and become more confident of your listening skills. Nothing that a reviewer says is going to change how the device sounds in your listening room. However we can at least outline some of the sonic attributes that one should observe closely. Trust your ears. And keep in mind that Audiophilleo sells its products factory-direct worldwide with a liberal in-home 30-day trial period. Competing products sold through knowledgeable online retailers such as Music Direct often come with liberal return policies (check the details in advance of course) and one may always audition or borrow the gear at a local audio store.


So far about nine different USB or FireWire interfaces have been auditioned in my reference and casual listening systems. Frankly most of them sounded rather poorly. Taking them out was a relief. Regardless of marketing hype, low price or glowing reviews by persons who should know better, these devices all burden the listener with pervasive colorations, roll-off in the high frequencies, grainy cold, edgy 'tight' presentations, reduced soundstaging, flat images or various combinations thereof. They just aren’t very good in my opinion.


While some experienced reviewers assert that cabling isn’t that important and that MP3 files sound perfectly fine through some very expensive DACs, take their suggestions with a grain of salt. Of course there’s always something to learn from another person’s observations but not all S/PDIF converters are created equally. Some of the inexpensive devices are terrific; a few of the very expensive ones don’t perform particularly better. In many ways these sonic undesirable qualities remind me of what comes out of the S/PDIF interfaces on many CD transports, DVD players and the like. Toslink by comparison is usually compressed dynamically and often mushy or congealed (to use technical terms). Eliminating these shortcomings is a good reason to spend some money and add a more specialized S/PDIF processor device to one’s system. After all what comes of out the DAC is largely dependent on the quality of the bit stream that feeds it. The best products so far are similar sonically but their feature set is quite different. The Weiss INT 202 previously reviewed favorably uses FireWire for data transport and has many virtues including an elegant custom remote control with attenuation and polarity. It also has a versatile AES/EBU output stage that can even support single-channel DACs.


An M2Tech hiFace Evo prototype also sounded quite good. One of its strengths in addition to good sonics are its nearly universal connectivity options. The Evo supports USB, external clocks, Toslink and ST fiber inputs and for outputs there are I²S, S/PDIF BNC and RCA as well as AES/EBU on XLR. However the Evo does not have any preamplifier functions, remote control etc. as do the Weiss and Audiophilleo. Compared to the Weiss and Evo my listening experience with the Audiophilleo suggests that having it in the loop makes the music sound even better in areas that matter to me. Firstly if you crave heart-melting lusciousness in strings and intimate naturalness in the human voice, the Audiophilleo adds something special to the experience. These qualities may well be the result of its (for audio purposes) vanishingly low jitter. Secondly it seems to have a slightly lower noise floor and is thus capable of displaying more detail in a natural manner. The music is more alive, accessible and there’s a greater sense of transparency to the source. The Audiophilleo dithering attenuator seemed to be responsible for the subtle improvement in dynamics.


The subtle differences between these three products become more apparent as one heads up into the higher sampling rates. Perhaps this is because the high-resolution regime is capable of revealing those fine details that illustrate the points we’re discussing. To tease these factors apart during a listening session one may for example select the Audiophilleo 1’s direct or pass-through mode which delivers bit-perfect data to the DAC without any local attenuation or dithering by the ARM9. Devices such as the popular Berkeley Audio Design alpha DAC (try finding one on the used market) and the Weiss DAC 202 implement attenuation in interesting and rather different ways, one of which you may prefer. For purposes of comparison you can easily switch back to using the dithered control in the Audiophilleo. The point here is that you have the possibility to mix and match during playback to help decide which designer’s approach you like best.


Thus which device delivers what functions is no longer static. One can use the Audiophilleo 1’s particular noise-shaped attenuator for example while making use of the specialized PCM decoding filters found in both the Weiss and Berkeley DACs. Thus a wide range of personal preferences can be accommodated and furthermore this example also suggests the increasing role advanced signal-processing software may play in voicing sonic qualities in digital systems. And if there’s a room-gain issue or slight channel level disparity between the amplifiers, the Audiophilleo 1’s digitally-controlled balance adjustment may be very handy indeed. The Weiss doesn’t allow you to do this; the Berkeley does by setting each channel’s attenuation independently. Most DACs—especially units more than a couple of years old—don’t have that much in the way of front panel display for key settings and operational parameters. The Audiophilleo 1 adds these features. The display can be set to very bright levels if need be and it’s easy to read from across the room. And it automatically falls back to lower brightness levels after a delay you select. These are all nice touches especially compared to more basic monochrome displays that rely primarily upon text instead of graphical indicators. The earlier illustrations showed a few of the Audiophilleo 1’s various screens.


Note the large dB numbers for setting the attenuation which Baby Boomers needing reading glasses may especially appreciate. These automatically fade to level indicators after a few moments but changing the volume immediately pops you back to the large numbers.


And there’s another really interesting and somewhat unusual set of features that may appeal to more experimentally-minded listeners. The Audiophilleo actually includes two independent sets of clocks. The first are the fixed-frequency reference oscillators it uses on a routine basis. The second set are of intentionally lesser quality to experiment with various levels of artificially induced jitter as well as simulate different cable lengths. This makes for a perfect learning opportunity on the 'sound of (higher) jitter' and results should be quite instructive.


Conclusion: The flexibility and overall functionality of the Audiophilleo 1 and 2 are about the best available outside of much more expensive larger standalone components. These debut products from a new designer stake out some important new ground with respect to the form, features and functions that make sense in today’s increasingly digitally-sourced audio world. The Audiophilleo combines to my thinking the beneficial results of starting from scratch—essentially bypassing decades of legacy architectures and concepts—with innovative state-of-the-art technical execution. And this package includes a host of well-done creature features such as the large display, preamplifier and jitter simulation functions. We’ll probably see more interesting products from Philip now that the Audiophilleos are launched and put to good use by digital audio enthusiasts around the world.

What’s in the box?
Just about everything including several international power plugs, a WireWorld Ultraviolet USB cable and BNC adapters. And then there’s the case.
Final comments: First of a new breed of digital audio devices. Possibly state of the art and definitely ahead of most of the competition.

Audiophilleo website
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