Audio over USB

The arrivals of the iPod, iPhone, Airport Express and Apple TV have raised the bar of consumer expectations of convenience when it comes accessing their music collection. With hard drives being as cheap as they are and so many new DACs coming equipped with USB inputs putting together a DIY music server seems like a better and better idea every days. However, like many things in high end audio it's not as simple as it first seems. At least two major factors stand between the interested audiophiles and good sound.

1. Jitter: In essence all of the "1" and "0" are present and in the correct order but the word clock that tells the DAC when to decode them is wrong. We're talking about fractions of a second here but our ears do pick up on it. Think of it this way. The world's best marching band all taking their time from a drummer with great rhythm vs. that same marching band with someone with no rhythmic sensibility. The musicians haven't changed, their instruments haven't changed, and the sheet music is still the same. But the rhythm won't be the same and things will start to sound sloppy and lax. Many of the new digital to analog converters are built specifically to reject incoming jitter are based on the Burr Brown PCM270x chips. That chip set has two major limitations. First it has a strong jitter component at 1kHz, which as misfortune would have it is smack in the audio band AND the frequency at which the human ear is MOST sensitive. Second, the chip is limited to a maximum sampling frequency of 48kHz which excludes it's use to transfer high resolution 88.2 kHz, 96kHz, and 192 kHz content. A better solution is a DAC capable of exploiting USB's asynchronous mode where the DAC requests the data when it is needed and therefore determining it's own word clock. Curently very few DACs on the market are capable of properly implimenting the asychronous mode because of the coplexity of the computer code necessary to make it work properly. Gordon Raskin, whose first career was in the computer world is one of the few people on the planet with a good understanding of bother sides of the problem. Currently his custom code is available in products from his company, Wavelength Audio and the upcoming QB-9 from Ayre.
2. Re-sampling: CD's are at a sampling rate of 44.1kHz which means that every second is broken up into 44,100 slices with each slice being described by a series of 16 "1" and "0." Microsoft in their infinite wisdom decided that most of their products translate everything to 48kHz or 48,000 by adding essentially garbage in a part of the program called the "K Mixer." According to the Wavelength web page the "K" mixer can be by-passed or mapped through as it's called (proceed at your own risk) by the following steps. "Go Control Panel => Sounds and Audio Device => Select Hardware Tab => Select USB Audio Device.
   
   Click Properties Button => Select Properties Tab => Click the “+” to the left of [+] Audio Devices that will pop down USB Audio Devices.
   Select USB Audio Devices and click Properties.
   
   Check both Use audio features of this device and Do not map through this device.
   ==> [ Apply ] <=="

Myrtle Wood Blocks

Many after market component support tweaks are manufactured from man-made materials and are made to extremely tight tolerances which results in a uniform "tuning" frequency. The uniformity usually adds some distinctly negative coloration in addition to the products sonic benefits. That doesn't occur with the wood blocks. Since the blocks are a natural material every sample is going to differ a bit. That might, in fact be part of why they work so well. Each block works on slightly different set frequencies because of variations in the grain structure and density of the wood.

During my time at an Ayre dealer I sold hundreds of sets of the wood blocks and told everyone the same thing, "If you don't hear a difference please bring them back." I can't speak for Cardas but Ayre is very picky about who their dealers are from a customer service stand point. If someone purchases a set and DOESN'T hear a difference I'm sure any Ayre dealer would let the customer return them for a full refund. I only had one set come back in over three years and that was because the guy owned Halcro gear and the standard feet were too tall to allow their use. I once sold a set to a hard core skeptic non-tweaker because his wife demanded that the system fit into an armoire and the CD player was blocking the top vents of his hot running preamp. When I told him that in addition to allowing the preamp to breath it would make the CD player sound better he gave me a complete "FUCK YOU" look. Three days later he called me back and bought three more sets for the other components because he had heard a difference even though he didn't want to.

The Ayre wood blocks in my system are used in sets of three because three points define a plane, with the logo right side up. Not to name drop but Charlie Hansen and Steve Sliberman of Ayre also feel it to be the best sounding orientation so I'm in good company. When I worked for an Ayre dealer Steve would only reveal his conclusions after I had done the experiments myself, they encourage people to "play" with the blocks. I do not believe that the benefit of the Ayre/Cardas myrtle blocks is in their resonant behavior ADDING a pleasurable element to the sound. I believe that the mechanism is the DRAINING of resonances AWAY from the component and into the equipment rack. I always place one block under the power supply of the component because that's usually the biggest source of vibration in components other than CD players and turntables.

Whenever possible the Myrtle wood blocks are placed against the side of a protruding screw, bolt, etc on the bottom cover because these fasteners are the best mechanically conductive pathways for vibrations. The amount of change in the sound just by making sure that they made contact with a fastener of some type was an ear opener. I found that chestnut of thinking while reading about Symposium products after Stephen Scharf's thread on DIY roller blocks had piqued my interest. The acoustic impedance of the wood blocks is much more similar to the metal (Myrtle wood being extremely hard) of the component bottom AND the wood of the rack shelves than the stock rubber feet offered on most products, thus it drain the vibrations away much more quickly and efficiently. I will admit that according to this theory the ideal situation would be to have metal shelves and metal footer, all made for more or less the same metal. Maybe Cardas should make some of these blocks, with the same dimensions in metal too. Why don't these blocks allow outside vibrations into a component as well as drain internal resonances away? I'm don't have a good answer to that question, but I assure you that I have thought about it.

To Ayre is Human

Recently, designer Charlie Hansen of Ayre was injured when he was struck by a motorcycle while biking on a trail. I have been fortunate enough to meet Mr. Hansen on one occasion. From the couple of hours that I spent with him he struck me as a passionate and honest individual, both things that are lacking in the world in general. Some of his friends have set up a blog so that we can all follow his recovery. It even has a comment section where one can leave their well wishes. The link will be added to the side bar to the right. Perhaps he will continue to update it after he has recovered. I think that it would be fascinating to watch the genesis of his next product. I Wish him a speedy and full recovery.

It's good to have connections

Under comparison will be three pairs of balanced interconnects. Ayre Signature, Transparent Balanced Music Link Plus, and Transparent Balanced Music Link Super. Each cable was broken in before evaluation began. Just to be safe each cable had eighty minutes of music ran through it as well as the thirty second Ayre sweep tone. Each song was played twice on each cable. The first time just for listening, the second time through was to confirm findings and to jot down quick notes. The cables were used between the Theata DSPro basic III DAC and my Adcom GFP-750 preamp in active mode. Interconnects between the preamp and the amp were Audioquest Panther. It would have been ideal if I could have had two pairs of interconnects on hand so that the preamp to amp interface would have also been changed as well but that proved impractical.

Music for the shoot out was Robinella and the CC Stringband’s “Man Over” off of their self titled major label debut, Belle & Sebastian’s “Is It Wicked Not To Care?” from the album “The Boy With The Arab Strap” and Thelonious Monk’s “This Is My Story, This Is My Song.” from the recent Columbia re-issue of “Straight, No Chaser.” Between each phase of the testing a break was taken to make sure that listerner fatigue did not become a factor. After this process I listened to two albums using each cable to double check my earlier findings and to deepen my understanding of each cable abilities.

Both Transparent cables utilize their network technology. The network has a number of duties that it is intended to perform. Every cable acts as an antenna, picking up RFI (Radio Frequency Interference) if you know the length of the cable along with some other key information it is possible to calculate at what frequencies this will occur. One of the network’s jobs is to get rid of this unwelcome noise. Transparent also believes that there is an optimum balance of capacitance and inductance, the network also helps to maintain this balance. The interesting effect of this adjustment of capacitance and inductance is that a 3 foot, 6 foot and 10 foot pair should sound virtually identical. In other cable designs this isn’t the case. Conventional audiophile wisdom says that the shortest cable will sound the best because it is the shortest signal path. But in practice short cables tend to raise capacitance which reduces bass and can cause the system to sound bright (all of these things affect speaker cables as well.)

In general the Ayre cable tended to mute the leading edge of plucked strings. On both the Robinella and Bell & Sebastian tracks acoustic guitars lost some of their fullness as a result of the transient response malady. The Ayre also had trouble when two instruments were playing the same melodic line, as the hollow body electric and the violin do on “Man Over.” This same tendency cropped up on the B&S selection when in the middle of the song a male voice comes in to double the female lead. The Ayre Signature also lacked space within the recording. It was as if all of the musicians took two steps closer together. The Signatures also tended to add a very slight grain to female vocals. This grain was also added to lower treble notes on Monk’s “This Is My Story, This Is My Song.” In addition with the Signatures in the system it was less than clear that Theo. was playing a grand piano.

The Transparent Music Link Plus was better with the initial attack of plucked acoustic instruments. The “Chugga-Chugga” of the mandolin on the Robinella song was a much bigger part of the song, setting the rhythm of the performance. Because this song, in fact the whole album lack a drummer this is very important. The bass on this track also had more body. The Music Link Plus also gave this performance more space so it didn’t sound as if the musicians were standing right on top of each other. At the beginning of the Bell & Sebastian number the female vocalist opens her mouth and takes a deep breath before delivering her first line. The Plus allows even this simple act to have more dramatic tension than the Ayres. The Pluses also allowed for a richer sound on Mr. Monk’s piano. Now there was little question that this was a grand piano.

With the Transparent Music Link Super both vocal performances were much more engaging than with either of the other cables. This was primarily due to a better sense of micro dynamics in the voices of both of the women. “Is It Wicked. . . “ took on a much more hushed, almost whispered quality to the vocals, increasing the intimacy of the lyrics. It was almost as if the performance was just for one listener. The violin on “Man Over” also seemed more emotionally engaging because it’s lines seemed slower and more lovingly played. The bass line, while not louder or deeper than the Pluses was easier to follow. Subtle flourishes on the acoustic guitar and mandolin near the end of the Robinella selection, that had previously gone unnoticed also added to the presentation. Theo.’s piano now IS undeniably a GRAND piano and this joint now takes on a much more dramatic and impressive tone because of it. The listener is pulled to the edge of their seat waiting to find out what the next salvo of notes will bring, even if they have heard the performance hundreds or even thousands of times.

Don’t judge the Ayre Signatures too harshly, none of their errors were on the magnitude of being major, if one didn’t have the opportunity to hear the Transparent cables it would be difficult to even notice these imperfections. Also I believe that the Martin Logan CLS electrostats tended to highlight these flaws because of their strengths in these areas. For a brief time Transparent’s Balanced Ultras were to be part of this survey but sanity and my pocket book got the better of me. I don’t want to listen to anything in my system that I can’t afford and take the chance on falling in love with them on the spot. I have heard them in other systems on many occasions and already know what I don’t want to know for sure, that they are a world class cable. Many years ago 7-Up used the slogan “The Un-cola.” Too bad it’s already taken because Transparent could easily and truthfully have used the slogan “The Un-cable.” Maybe they already have in their own way. Maybe that’s why they named their company Transparent. No single word better describes their character, or lack there of.