In depth Details From PS Audio Site - Page 2
The PerfectWave Transport Memory Player
The idea behind the PWT started with the simple realization that there is no technical reason why storage mediums should affect the quality of the music's performance. Properly designed and executed, digital audio data should sound the same regardless of how it was stored: on an optical CD, DVD, magnetic hard drive or solid state memory. In 2006, when the PWT project began, not one of these storage mediums sounded the same when played back. By default, if none of these sounds the same, then none of these can be accurate to the original.
CD players and CD transports all sound different. Music stored on a computer sounds different than any of the other technologies for digital audio playback. These observations are shared by nearly every audio reviewer and high-end audio owner in the world, despite the fact that when examined on a bit-for-bit basis all digital audio output data is the same as the original in memory.
PS Engineers have understood, since the early days of CD players and transports, that both CD mechanisms and computer hard drives are mechanical devices trying to perform in a world of precise timing. Audiophiles have struggled to compensate for some of these problems for years: painting the edges of their CD's green, putting expensive mats on top of the CD, damping the mechanical mechanisms and spending thousands upon thousands of dollars buying what is advertised as the latest in CD technology. Unfortunately, few of these efforts have addressed the core problems in CD playback. Instead, they are like applying a Band Aid to a wound.
The PWT is like the Power Plant of CD's
It is, in fact, a minor miracle that a CD mechanism works at all. The mechanical devices that control the laser reading mechanism, the varying rotational speed of the disc, the wobbling of the CD and the errors that must be corrected for even the best CD's all need separate feedback based systems to correct for their errors. While engineering marvels to be sure, these systems of error correction are themselves Band Aids and not perfect solutions.
Until the advent of the PerfectWave Transport, every CD player ever built relies on the same mechanical technologies and suffers from the same problems as every other. PS engineering realized that instead of applying better Band Aids to the problem of CD playback we needed to design an entirely new system that accepts any quality digital audio data and outputs perfect data in its place; a system that is not affected by disc, data or mechanical/optical performance issues.
To accomplish this we fashioned the PWT after the design concept of the Power Plant AC regenerator. The Power Plant concept acknowledges that we cannot control the quality of the home's incoming AC power, nor can we fully repair its problems. Instead we simply ignore the problems, start over and generate new AC, thus eliminating the problem entirely. There is no connection between the input and the output of a Power Plant.
The concept for the PWT is very similar in that there is no connection between the input and the output of the PWT. Unlike a traditional CD transport, you are never listening directly to the data from the optical disc. Instead the data is pulled off the disc and sent to the internal Digital Lens where it is rebuilt and stored for up to three minutes and then output by the asynchronous (unrelated) clock.
You can see this for yourself on the PWT video accessible here. Once the disc is inserted into the player, you can actually remove it and the music will continue playing.
The color touch screen display
Building the perfect transport means more than just producing the perfect output. The transport should also be a joy to use and answer a higher level of expectation from its owners.
Every CD player and transport, since the inception of the CD in 1982, has included a compromised user interface. This includes everything from a simple LED display with track numbers and times, to complex color LCD's that look like they were designed to be in a circus. None of these interfaces addresses what music lovers really want; the information that is included on the CD case.
Since 1948, when the vinyl LP was first introduced, music lovers around the world got used to reading album covers and liner notes associated with them. When CD's came into popularity they were housed in miniature copies of albums with small cover pictures and even smaller lists of song titles and liner notes.
60 years after the introduction of the vinyl LP, there are still very few players that recognize and display cover art and song titles from the disc itself. The engineers at PS Audio determined to put this shortcoming behind us with the introduction of the PWT's touch screen display.
Once connected to an internet capable network connection, the PWT will display the cover art and song titles of just about any CD or DVD you place into it. To do this, the PWT automatically identifies the disc that has been inserted. The PWT then communicates with PS Audio's Global Net servers over the internet and the information for that CD is downloaded and displayed on the front panel color touch screen.
No longer do you have to have the CD case in-hand to figure out which track you wish to listen to. Simply scroll through the actual song titles on the disc itself and touch the track you wish to hear. The PWT will instantly play the selected track.
Your personal library
Every time you play a disc in your PWT a copy of the cover art and song titles are kept for you on your own private library page through the PS Audio website. Here you can manage your entire library of information.
Global Net's ability to accurately retrieve perfect information and cover art for the millions upon millions of CD's in the world is not perfect. Should the PWT display either incorrect song titles or cover art, it is a simple matter to access your personal library page and correct the information. Once corrected, your PWT will display the new information accurately every time.
High resolution WAV files on DVD
The future of audio is to be found in higher resolution media than CD's. CD's are limited to 44 kHz and 16 bits. Ask anyone in the engineering community about the inherent limitations of CD's and you'll likely get an earful.
For CD's to approach and, in many cases, exceed the musicality of vinyl and master tapes, higher sample rates and bit depths are required. 24 bit, 96 kHz is a minimum for high resolution audio and even higher sample rates (up to 192 kHz) are best. The future is bright indeed with high resolution audio now entering our lives.
The first high resolution audio discs were DVD-A (DVD Audio). The next attempt was SACD (Super Audio Compact Disc). DVDA failed because of restrictive licensing issues and today there are very few of them left. SACD was a format introduced by Sony and was well accepted in the high-end community. Unfortunately, Sony did not make the format public so other manufacturers and record labels could embrace it. This restrictive policy lead to the death of SACD as a possible high resolution format and Sony has since cancelled future SACD releases.
Record labels still interested in high resolution audio have since taken matters into their own hands and are using WAV (Waveform Audio Format), recorded onto a DVD, as the basis of new high resolution releases.
WAV is an uncompressed audio format for Windows computers (AIFF is the Macintosh equivalent). The advantages of WAV are many but perhaps most important is that the format is open to the public, can handle high resolution audio files easily and is being adopted by many record labels as the format of choice.
The disadvantage of WAV is that, up until the introduction of the PerfectWave Transport, you had to rely on a computer to read the WAV files from a disc or from downloads; all that has changed with the introduction of the PWT.
The PWT can read WAV files directly off a DVD and present jitter-free digital audio data to your DAC with resolution up to 24 bit and samples rates as high as 192 kHz. This is a stunning achievement for PS Engineering. The ability of a standalone dedicated transport to read DVD discs is unheard of and the PWT is the only product in the world with this ability.
To gain some further insight into the world of high resolution audio, and its emergence through the record labels as the format of choice, click here to read our newsletter on the introduction of the PWT with Reference Recording's HRx format.
The PWT is future-proof. Through either its rear-mounted SD memory card, or through online access, the PWT's operating system and feature list is upgradeable by PS Audio for its customers. This allows PWT owners to keep up with any future upgrade paths without returning the PWT to the dealer.
The first upgrades planned after the initial release of the PWT will be the addition of new CODECS to read compressed file formats off of discs.
All digital audio is organized in one of several formats that must be decoded to present to a DAC so you can hear the music. CD's, for example, are organized in a format very different than DVD's. The job of the PWT's internal engine is to make sure whatever is on a disc can be read properly and organized into exactly the right format for the DAC.
CD's and DVD's can store more than just their native formats. They can be used to store different formats such as WAV, FLAC (Free Lossless Audio Codec), AIFF (Audio Interchange File Format), MP3 etc.. Many of these formats, like MP3 and FLAC are used to compress data into smaller file sizes. MP3 is known as a lossy compression, meaning they strip away valuable audio data to compress the music to a smaller file size. FLAC is a lossless compression method, meaning there's nothing lost in the compression process.
All these formats use what engineers call a CODEC to translate files into something your DAC can use to play music. The word CODEC is a portmanteau of 'compressor-decompressor' or, most commonly, 'coder-decoder'.
The first CODEC scheduled for release with the PWT will be a FLAC decoder. This upgrade will be free and available to PWT owners sometime in late spring 2009.
Inside the PWT
Given the technological wonders the PWT offers its owners, you might think that we simply took a computer and stuffed it inside the PWT chassis like other manufacturers do. Nothing could be further from the truth.
Taking a computer motherboard along with its input and output components and building a high-end product around it is, in our opinion, a compromise. No computer is designed with high-end audio requirements in mind. They are noisy environments that were never intended to produce jitter free digital audio data without digital manipulation.
The PWT was designed from the ground up with its own hardware and operating system dedicated solely to the reproduction of music.
Inside, the PWT is deceptively simple. The heart of the PWT is a 440,000 gate FPGA. An FPGA (Field Programmable Gate Array) is like a giant microprocessor that can be configured to do whatever the engineers want. It has no built-in functionality whatsoever and is hundreds of thousands of assignable cells or gates operating from a custom bit of software.
Let's follow the path of the PWT as it extracts the data from your optical discs.
First, the ROM drive
Your disc is read from a computer style disc drive known as a ROM (Read Only Memory) drive. Unlike a conventional CD disc drive that you find in any transport or CD player, a ROM drive is completely controllable from an operating system and is independent of any standard disc extraction and error correction methods built into CD and CD transports.
The use of an independently controllable optical disc drive is a critical element in the PWT's success. With a standard optical drive, even a great one like the Philips CD PRO2 top loader (used on only the most expensive CD players and transports), the data is read and error corrected by the mechanism itself without allowing any choice over how it is done.
Using a ROM drive, we can read the data using an entirely different approach that requires no error correction.
Our goal with the PWT was to extract the data from any optical disc in bit-perfect form without the use of standard error correction used by all CD mechanisms.
Standard error correction uses a predictive system that "guesses" what the data should be if there is an error detected on the disc. A better system, such as the PS Audio Multiple Read Error Correction system (MREC), reads and then rereads the data as many times as necessary until a bit-perfect match is achieved. This read and then reread system is what the PWT uses to extract bit perfect data from the disc.
Once the data has been taken in bit-perfect form from the CD or DVD, it is sent to the PWT's internal Digital Lens.
The internal Digital Lens
Inside the PWT there is a built-in Digital Lens.
A Digital Lens is a device that takes digital data in and focuses it down to a single perfect point at its output. The first Digital Lens was designed by PS CEO Paul McGowan and PS VP of engineering, Bob Stadtherr, back in the early 1990's. It was released as a Genesis Technologies product and was an immediate best seller. Nearly 20 years later, used Digital Lenses are purchased almost as soon as they become available on the used market; they were that good.
The digital Lens in the PWT has three elements: an input data organizer, a 64mB memory, an output data organizer. Musical data is taken off the optical disc, fed into the Digital Lens where it is stored in memory until the output digital organizer and final clock ask for the data.
The Lens allows the ROM drive to have enough time to read and reread the data as many times as it wants and equally important, allows the output asynchronous clock to operate at a fixed and independent rate.
The output asynchronous clock
The CD player or CD transport provides the operating clock (timing) for the entire digital audio system. This clock is critical because it runs the DAC and everything else in the system.
There's probably no place in the digital audio chain more important than this clock and, oddly enough, few high-end CD players or Transports pay much attention to it. This lack of attention to the master clock is one of the biggest sonic handicaps of all CD player and Transport ever made.
Some manufacturers have gone to extraordinary lengths to solve this problem, including external clock inputs and super accurate time bases that use atomic clocks to maintain accuracy.
While certainly effective, the extraordinary measures are expensive and unnecessary if you get the clock architecture right in the first place; and the PWT gets it right.
The proper way to build a transport is with an asynchronous clock with a Digital Lens feeding it. Only the PWT has this capability.
An asynchronous clock sounds pretty technical; it is not. It simply means that the master clock is completely independent from the optical disc reader.
In a standard CD player or Transport, the master clock is synchronized to the optical disc reading mechanism. This means you are basically relying on a mechanical spinning mechanism and all of its correction systems to give you a perfectly stable, fixed clock to feed the DAC. It does not work and it is not stable.
Here's the problem. Optical disc readers are constantly changing the rate at which the data is coming from the disc. Sometimes it comes faster and sometimes it comes slower than the fixed speed of an asynchronous clock. If that data is coming in faster than the clock, you get a traffic pileup and the system crashes. Too slow and nothing comes out.
The Digital Lens has a large and smart memory storage buffer. It's big enough to handle any speed variation of the optical disc reader. Because it is an intelligent buffer, the length of the memory is automatically adjusted to fit anything the optical disc reader is doing and feeds the master clock what it needs and wants. The system is really quite simple.
The results are amazing. With a fixed asynchronous clock fed by the intelligent Digital Lens, the output master clock is accurate and jitter free supplying perfectly timed data to any DAC connected. The results are immediately apparent the first time you sit down to listen. In fact, this new architecture means the use of sample rate converters in DACS is no longer necessary or even desirable.
I2S through HDMI output
There are two ways to get the digital audio data out of the PWT: standard S/PDIF/AES/EBU digital audio outputs or I2S. I2S (pronounced "I squared S") is the preferred method if you have the PS Audio PerfectWave DAC that can receive it.
To understand I2S it is necessary to first understand the standard digital output, S/PDIF. S/PDIF stands for (Sony Phillips Digital Interface) and was invented by Sony and Phillips over 20 years ago as a simple and convenient method of transferring digital audio over a single RCA cable or optical cable. 25 years ago, when the format was invented, no one ever dreamed that a quarter century later high-end music lovers would not be happy with the compromised performance of S/PDIF.
S/PDIF takes three separate internal clocks along with the raw music data and combines them into one stream and sent out with an RCA, XLR or optical cable to the DAC. Once that single stream is received by the DAC it must be separated back into the multiple clock and data streams in exactly the same timing and form it started. The problem is the encoding and decoding of these complex critical clocks is never perfect. Through this flawed process we get jitter and timing error that we can easily hear.
A much better way of delivering the clocks and the data between the transport and the DAC is to not mix them up in the first place. This is what I2S does. Instead of trying to stuff these clocks and data into one stream, I2S simply transfers the three clocks and the data on separate cables to the DAC. Done in this way, there's no chance for error or increased jitter and the audible results are simply stunning.
PS Audio has searched for a long time for the perfect cable to transfer I2S data. Some manufacturers use CAT-5 which is the cable your computer connects up to the internet. We took one look at this method and rejected it out of hand. The best solution we found was HDMI (High Definition Multi-media Interface). An HDMI cable is the best multi-conductor digital cable made today and it was the obvious choice for the PWT.
Simply use any HDMI cable between the PWT and the PWD and you are transferring data perfectly.
Outside the PWT
The chassis of the PWT is a metal sculpture that rivals the best ever built. A combination of aluminum and steel, the PWT weighs in at 20 pounds of elegance and beauty. The top cover is a hand painted, hand polished piano black cover that has been lavished over for hours.
When you receive your PWT, you'll find a pair of soft white gloves to pull the unit out of its protective cotton sleeve and unveil its beauty. Every person who has had the opportunity to see a PerfectWave in person has the same initial reaction: they reach out and softly caress its finish and admire its beautiful lines.
Built in Boulder
The PerfectWave series is assembled, programmed and tested at our new production facility in Boulder Colorado. Instead of the typical production line process, each PWD is hand built by one person from beginning to end. There is a measure of pride of workmanship that goes into every one of these PerfectWave products and it shows from the moment you open the unit up and plug it in.
This is one gorgeous piece of equipment and just the beginning of the most beautiful natural sounding audio equipment you have ever had the privilege to own.
The last transport you'll ever need
The PerfectWave Transport is a revolution in product development and a pure joy to use. It plays both DVD as well as CD. It finds and displays cover art and song titles on its beautiful color touch screen.
It easily handles both standard CD playback as well as high resolution audio files directly in the machine.
The PerfectWave Transport is the last optical disc player you will ever need or want.
It's funny how sometimes temporary names just seem to attach themselves to products and stick forever. Such is the case with the PS Audio Network Bridge. Best known by everyone as simply "The Bridge" the PS Network Bridge is the link between the home network and your high-end audio system.
Sure there are other streaming audio solutions, but none that brings true high-end performance coupled with the fun of a great user experience like the PS Audio approach.
The Bridge has been in the works for over two years and represents the single biggest engineering project ever tackled by the PS Engineering staff. The work was completed by a team of 15 engineers, programmers and coders located in Russia, Rhode island, Cupertino and Boulder. Truly, this was a worldwide effort of some of the brightest people in the industry and a monumental achievement now that it is done.
To bring together the fun and utility of a music library with the zero-compromise performance of a high end DAC and make it painless and brainless to install for our customers. Why was this important to us?
It's because the engineering people at PS Audio want to change the world. It's just in our blood to want to make a small dent in the universe and delight our customers with products that redefine how we listen and enjoy music in our high-end systems.
When we started the PerfectWave DAC and Network Bridge project we did so because there was nothing available on the market that combined the fun and ease of use of a well designed user interface and digital storage library with the no-compromise performance of a high-end DAC and frankly, we wanted one. We wanted it badly and so too did our customers. Two years later there still isn't anything as complete as the PerfectWave/Bridge setup and once you get your hands on this system, you'll see what we mean.
The Bridge is the missing link that, for the first time, marries a high-end DAC to a fun-to-use network music experience without any sonic compromise whatsoever. Certainly there have been many attempts by others and some of these get the performance right, but are not as fun to use. Some are tethered to computers with USB umbilicals, which means the computer is always in the listening room, others are fun to use but don't perform, and the list goes on. Only the PerfectWave DAC and Bridge combo combine all the elements together in one cool, fun-to-use package with 32 bit high-resolution performance that is simply breathtaking.
A bit of history
The beginnings of the Bridge are rooted in the beginnings of the CD itself. CD's started shipping in 1982 and didn't really get any interest in the high-end community until several years later. For the most part our community of high-end'ers shunned the optical discs until the early 90's when technologies started catching up with the performance levels of vinyl.
In 1994, PS Audio's co-founder (Paul) and PS Audio's current chief engineer, Bob Stadtherr, built the world's first asynchronous re-clocking device for improving the performance of CD's, and it was named the Genesis Digital lens. Our good friend and founder of Infinity Loudspeakers systems, Arnie Nudell, is credited with naming the Digital Lens. Arnie, a physicist by training, felt that because the Lens focused all digital data down to one perfect point, the term "Lens" was appropriate. History proves that he couldn't have been more correct and the Digital Lens was born.
This revolutionary device stunned the audio world when customers discovered they could take any quality CD transport, from the cheapest to the most expensive, and get analog-like performance out of them. In one remarkable device, the high-end community realized that most of the problems they were hearing with digital audio could be fixed by using an asynchronous clock coupled with a digital memory buffer. Even today, some 17 years later, the Genesis Digital Lens lasts about 5 minutes on the used market as they are swept up as soon as they come online.
The technology behind the Lens addressed one of the major problems in digital audio: jitter. Jitter is basically a timing issue between the main system clock and the musical data and when you have a lot of jitter, you get poor performance that is very "digital" sounding.
In the early 90's, everyone was trying to lower jitter by filtering it. Paul and Bob decided those were simple inadequate Band Aids and since our goal was to eliminate jitter, not just lower it, Band Aids wouldn't do.
We needed a real fix and to get that fix, we we had to throw out all the clocks and timing information, separate out just the musical data in the digital stream and then rebuild everything back from scratch. So we designed a simple method of stripping out everything but what we needed, placing that musical data into a large intelligent memory and then rebuilding the data and the clocks from an asynchronous device at the output. The results were spectacular. Re-clocking solved a myriad of digital problems and eliminated the dreaded "digititis" music lovers all over the world hated. We had achieved analog quality sound from the Digital Lens.
In fact, the idea to "regenerate" a brand new data stream to solve this problem was also the basis of another product that debuted later in 1997, the PS Audio Power Plant AC regenerator. Both the Lens and the Power Plant would use the same idea: rebuild and regenerate for perfect results. The Power Plant rebuilt perfect AC power and the Digital Lens rebuilt perfect digital music.
Back to today
When we began auditioning the streaming audio solutions available a few years ago we realized that their performance was all over the map; but that map didn't include high-end performance. Even if you took the digital stream output of these devices and played them through a high-end DAC they still didn't perform to our standards. Worse, none of these solutions would address high-resolution audio requirements of 192kHz 24 to 32 bit media that was beginning to appear on the scene.
This was a familiar problem to us after our work on the Digital lens. So we decided early on that stripping and rebuilding to perfection using Lens technology was going to be the key to our success in the world of connected audio.
Our first new product to incorporate the Lens technology would be the PerfectWave Transport (PWT). The PWT uses a 64mB Digital lens inside to produce high-performance audio from CD's or DVD's and if you've ever had the good fortune to listen to (or even own a PWT), you know what we mean.
The challenge with streaming music over a network was to create a network interface that would provide performance equal to or better than the PWT. The interface would use the a modern day version of the Digital Lens technology to achieve this. Once built, all we needed to do was create a fun and useful portable interface to scroll through your library and we'd have a killer product.
That killer product is the Bridge and the bridge and PerfectWave DAC will change the world of high-end audio. This is the silver bullet we've all been looking and waiting for. The Bridge and DAC represent the best no-compromise approach to high-end audio we have ever seen or heard. Once you get to play with the interface and listen to the Bridge/DAC combination, you'll never be able to go back to anything else, including CD's and DVD's.
The Bridge is a custom designed PC board that slides into the back of any PerfectWave DAC. When you hold it in your hand, it doesn't seem like much; but don't let its small size fool you. Under the hood of the Bridge is an incredible high-resolution 192kHz 32 bit capable network interface with innovations and technological breakthroughs galore.
The bridge is unlike anything ever built to date. Instead of a "quasi asynchronous" clocking system found in most systems we have investigated, the Bridge is a true asynchronous parallel 32 bit system approach. This means that there are actually two low jitter isolated and separate clocks (44.1kHz and 48kHz) that are completely unrelated to any other clock in the Bridge for true asynchronous performance.
There is also no digital manipulation of any kind going on in the Bridge, either through sample rate converters or DSP's whatsoever. While many of our competitors rely on system wide clocking and digital manipulation to lower jitter and improve performance, only the PS Bridge has a real Digital Lens built into its architecture, providing low jitter I2S music without any digital manipulation and the differences are easy to hear; the PS combo is simply stunning.
The bridge contains all the CODECS (programs) to convert just about any format of audio into what the PerfectWave DAC wants for perfection; I2S. Once the Bridge gets a network music stream, it figures out what the native format is (FLAC, WAV, ALAC, MP3, etc.) and converts the format into a pure digital audio stream without any associated clocks. This is important because this data, once converted to its raw format, can then be placed into the 256mB memory of the Digital lens and then output in I2S directly into the DAC.
The I2S format has separate clocks and data lines that never mix with each other and therefore there is little to no jitter. The Bridge can accept any format with resolutions up to 192kHz, 32 bits and feed that info directly into the PWD for sound that simply takes your breath away.
Compare the sound of a CD or DVD disc through the PWT into the Bridge/DAC combo and the differences are so small (if at all) that you'll have fun debating your friends on which one they are listening to. In multiple side-by-side A/B tests here at the PS Audio Reference System, differences between the Bridge and PWT are so small as to be non-existent.
Just for the fun of it
The bridge allows PWD owners to enter the world of connected audio and rediscover their music in a fun way that has no compromises. You aren't tied to a computer, you can store your music anywhere in the house (as long as there is a network), you can connect either wirelessly or wired, and perhaps for the first time in a very long time, you'll be having more fun with your collection than you have in years.
The Bridge and PWD combo will change everything in your system and allow you to build a glorious musical library your friends and family can enjoy for years to come. Think of the difference between thumbing through the collection of CD's in your shelf compared with the fun of having your library and artist information right at your finger tips with the hand held controller.
With the PS system you can build playlists, compilations, listen to radio, sort through everything that's high-resolution, listen to music and artists as never before. For perhaps the first time the thrill and discovery of a music library system comes alive in your hands and you never have to worry that you're missing something in the performance.
With the PS system, we simply do not tolerate compromise in the performance.
The PS connected audio system
So, how does this install and work? Is it easy? Can anyone do it or do you need a network expert? What's inside the package?
First off, it's easy and no, you really don't need to know anything about networks or computers or drivers or, for that matter, anything to make this work. The Bridge is basically a true plug and play device. Once installed you connect it to the network and everything else is automatic.
Second, there are several simple elements you need to make this system work and we will go through those elements now.
A connected audio system has three elements necessary:
A player (the DAC/Bridge) Music stored on a hard drive or memory of some kind A controller
The player is simple. Get a PWD, insert the Bridge into the back, connect the DAC up to your high-end system and the bridge to your home's router (either wireless or wired) and turn on the switch to play music. The controller will "see" the bridge and allow you to connect to it with the touch of a button. It's just that simple.
Music stored on your computer or external hard drive is pretty simple as well. The Bridge will play just about any format of encoded music ever designed; either lossless or lossy, high resolution or standard resolution. FLAC, ALAC, WAV, AIFF, MP3, OGG, APE and the list goes on until it gets boring. The only thing the Bridge will not play is SACD and this is because of digital rights problems through Sony who will not permit you to copy the SACD onto a hard drive and stream the results.
A controller is also a simple issue. The controller is the interface between your stored library of music and the Bridge. The controller lets you scroll through everything in the library, create playlists, read cover art, artist's bio's etc. The controller is the FUN part of the connected audio experience.
There are numerous ways to control the PS Audio Bridge: from your computer or from a portable device. The most fun is from a portable device and here is where we have partnered with Apple.
Using Apple's extremely affordable iPod Touch, or an Apple iPhone or iPad, you can load the PS Audio controller app and be instantly connected. The PS Audio app will soon be available for download on the iTunes store and provides a fun and rewarding experience controlling everything in your library.
The app will also control every feature on the PWD, including sample rate, phase, filters, inputs and volume.
Using the app couldn't be easier. Cover art and artist's bio are sent over from the PS Audio servers automatically as long as your network is connected to the internet. Everything just happens without anything required from you, the user. Scroll through the library, find something you want to hear and simply touch the song title. The system immediately begins to play, setting the correct sample rate and filter setting automatically.
Radio, playlists and an awesome experience
Using the Apple based controller gives you a number of advantages: among them full access to internet radio, including PS Audio's own eTracks radio station offering great, commercial free high-resolution programming into your home.
You can also build and use playlists right on the iPod Touch device with just the flick of a finger. There's a great video of all the features and functions available on the iPod Touch or iPad version of the PS Audio app that does a great job of explaining everything. Simply click on the video to watch.
The PWD front panel
If you own a PWD you know how cool the front panel touch screen is and what a joy to use. If you don't own one, head to your local dealer and try it out. The PWD plugged directly into a power amplifier (or into a preamp) can change the way you think about your music system and provide a tremendously rewarding experience matched by nothing else in the industry.
The PWD's apodizing filters, Native resolution options, fully discrete analog output stage and 32 bit resolution make it one of the best sounding DACS in the world and now that it is also a music server, the front panel touch screen comes alive in a way you may never have expected.
When you install the Bridge into the back of the PWD, the entire touch screen interface on the front panel of the PWD takes on a whole new purpose; that of controlling your network media and displaying cover art as the music plays.
Using the front panel touch screen, you can scroll through any playlist you have loaded into the bridge, choose the next track from an album that's playing and, most important, watch full view cover art as you play what's in your music library. It really adds a whole new dimension to the PerfectWave experience.
What's inside the Bridge?
A lot of technology and programming. This is not just a small off-the-shelf computer motherboard like a lot of companies have turned to, but a complete custom in-house solution designed by the hardware specialists at PS Audio in Boulder.
The Bridge is based on 32 bit architecture with the core processor running at 500mHz and uses 256mB of high speed DDR memory for the lens. The data is clocked out of the DDR memory into a custom CPLD (Complex Programmable Logic Device) that organizes each of the 32 bit frames into the requisite I2S format. That I2S data is then clocked out of the CPLD with one of two custom, low jitter, fixed frequency asynchronous clocks (depending on the sample rate) and finally leaves the Bridge and into the PWD through high speed buffers powered by a separate supply in the PWD.
How is this different than everyone else?
Of course we cannot say with complete confidence what "everyone else" is or will be doing now or in the future, but here's what we can say with confidence. The majority of the few connected audio streaming devices on the market today are based on either a small PC type motherboard or off-the-shelf microprocessor based solutions with integrated clocks and little to no control over the way the data is handled and manipulated. With very few exceptions, these solutions do not come close to the performance of the PS Audio bridge.
We knew from the beginning of our project that in order to give our customers a true high-end PS experience - one that would ensure that they would never have to be concerned about performance compromises - we had to do everything from scratch. This means the firmware that runs the system, the hardware it runs on and the basic architecture these platforms use to work their magic.
The results of all this hard work are immediately obvious the first time you listen to your PWD with the bridge installed. It's almost hard to believe you're listening to streaming audio from a hard drive located somewhere else in your home, but it's true. This is really a revolutionary experience and one we highly recommend you enjoy at your earliest opportunity.
Getting back to what it's all about
There was time in many of our customers lives that playing music was a more rewarding experience than it is now with the advent of the CD. In days past the vinyl experience would include pulling out the record, reading the cover and liner notes as the music played in all its analog glory. When the CD came into existence it brought with it a new audio experience but we lost some of the original vinyl experience. With the PS Audio bridge, the fun is back.
There's simply too much to write about to give you the full story and to relay the experience of a library full of music available at the touch of a finger through the PS Audio bridge and DAC combo. We encourage you to visit your local PS Audio retailer and take a Bridge/DAC combo home and play with it for a week. The experience is something that is absolutely addicting so be careful: once you try the bridge there's simply no going back to what you had in the past.
The PS Audio Network bridge changes everything and completes the goal set by our engineering staff two years ago: to make a small dent in the universe and change the world. Welcome to the future.
The groundbreaking PerfectWave Digital to analog converter (PWD) is a remarkable product. It accesses high-resolution digital audio data from multiple sources such as a CD transport, CD player, computer, network, or the Internet and converts the data to the most musically natural sounding analog audio ever produced.
The PWD is the first high-end product to fully transcend the limitations of traditional digital to analog converters (DACS) by providing uncompromised performance for any media delivery or storage system possible. This means that it no longer matters how the digital audio data is stored or delivered, the PWD produces the same high performance audio sent over a network, taken from a hard drive, a CD or even downloaded via the Internet.
The PWD is a complete solution that can be used in a multitude of ways. As a standalone DAC, the PWD will accept inputs from any digitally connected source such as a CD player, CD transport, satellite receiver, music server or computer.
As a music server, the PWD can access and control any DLNA compatible network source such as a network hard drive (NAS), or stream music directly off the Internet.
As a preamplifier control center, the PWD connects directly to your power amplifier controlling both the volume and any of the seven (possible) connected sources.
If you are not interested in playing optical discs (CD's or DVD's) directly, the PWD a network connection and a power amplifier are all you need for a complete high-end music system the likes of which have never been available in one affordable, easy to use, high-end product.
Full color touch screen
The PerfectWave DAC has a simple faceplate with only two elements apparent: a power button and a color LCD touch screen. Through the touch screen you can control an amazing number of features, functions and even music.
As a DAC, you can use the touch screen to select any of the 7 digital inputs and assign any one of 6 sample rates and 5 filters that fit that input perfectly and the choices will be memorized by the PWD. You can control the phase and the volume with a simple touch of your finger or press of the supplied remote control. You can even assign each of the inputs a custom name so instead of the usual "input 1" it can now read "PerfectWave Transport", "Music Server", etc.
As a Music Server (with the optional network Bridge installed), the touch screen becomes an indispensible tool that allows you to scroll through your connected music library, tune Internet radio stations, see cover art and song titles of what is playing at the moment and perform any network setup tasks that may be required.
7 digital inputs
The PWD has 7 digital inputs that include two I2S over HDMI, an optical TOSLINK, coax S/PDIF, balanced AES/EBU, 24 bit 96kHz USB and the network Bridge (available this summer).
The most unique and valuable inputs on the PWD are the HDMI and the network Bridge. The remaining digital inputs are standard types that connect compatible equipment and accept up to 32 bit 192kHz digital audio signals.
The HDMI inputs are designed not for accepting HDMI data, but instead are utilized in a unique PS designed standard for I2S data. I2S data is the native data management system within every transport, CD player and DAC. It consists of three separate clocks and one digital audio data line.
When a separate transport and D to A processor are used in a system, the I2S data inside the transport is typically mixed together to form one single data line so it can easily be transferred between the transport and the DAC through either optical, coax or balanced means. The format used to send this data is called SPDIF (Sony Phillips Digital Interface) and is found on every CD player and transport from the least expensive to the most expensive units.
Once the S/PDIF signal is received by the DAC it must then be separated back into its I2S components and that is where the trouble lies. The process of encoding and then decoding the I2S data into SPDIF data compromises the audio quality on a high-end system. The PWD's unique I2S over HDMI solves this problem in a simple elegant fashion and the audible results are breathtaking. Openness and clarity like you've never experienced in your digital audio system; ever.
The PWD has three I2S inputs. One can be used for the PerfectWave Transport (PWT), the second can be used for future products we build or for the addition of the upcoming PS Audio Digital Lens. The third is accessed internally by the optional network Bridge.
The PWD as a music server
Perhaps the single most unique feature of the PWD is its ability to become a music server with its optional network Bridge. Simply stated, the Bridge is the PWD's connection to the outside world. With the Bridge installed, the DAC is no longer tethered to your nearby components. Instead, the DAC now has access to digital audio data from anywhere in your home or anywhere in the world. The Bridge spans the gap between the first D to A converters ever built and the new age of interconnected audio data from all over the world. It is, in fact, a bridge into the future that turns the PerfectWave DAC into the PerfectWave music server.
To understand what the Bridge is and how it enables the PWD to become a music server, let us first spend a little time understanding what a music server is and then how these concepts all tie together.
A music server is a digital audio library with a convenient way to access and playback all the material in the library. It is a mechanized version of what we all do: search our CD or vinyl collections, choose what we want to hear, insert the media into our players and enjoy.
To build a music server you need 4 elements: a user interface, a means of storing the music, a way of accessing that stored music and a way to playback what is stored. The PWD comes to you from the factory with the first and the last required elements built in; the middle two (storage and access to the stored media) are needed to complete the chain.
The first task is to store your music. There are really only two choices to store music; on an internal or external hard drive. Using an internal hard drive is restrictive because of potential noise issues and the chassis limits the size and type of drive. External hard drives offer absolute quiet remote operation and the greatest freedom and flexibility between the two options.
The PWD system is built around the external remotely located hard drive. This is by far the best solution because it allows PWD owners to choose from hundreds of available options and sizes and allows for unlimited future expansion of the library.
The average 2 or 3 thousand CD collection can be stored on 1 to 2 terabytes of data with no loss of quality. With the many available external hard drive options, a 2 terabyte drive can be purchased for $300 and those prices a dropping rapidly. These high quality drives are available all over the world and with PS Audio's intuitive plug-and-play architecture, installing the drive couldn't be easier.
Connect any DLNA compatible NAS (there are many to choose from) to your home network, copy your music to the NAS and you are done. The PWD will find the NAS anywhere in your home, or even a thousand miles away, and you are ready to play.
Instead of a fixed volume hard drive installed into a piece of equipment in your listening room, the PS system offers you the ultimate freedom and flexibility that only a network attached storage device can offer. The NAS can be stored away from the listening room, added to at any time, has no size restrictions, easy to backup and easy to share with your friends.
Accessing the stored music is the job of the PS Bridge.
The network Bridge
Inside the Bridge is a remarkable piece of engineering that consists of 3 main elements: the communication portal, the musical format interpreter and a Digital Lens.
The communication portal allows the bridge to communicate with devices on your local network or on a remotely located device or service through the Internet. If your home has DLNA compatible storage or media devices on the network, the Bridge discovers them automatically and makes them available through the front panel touch screen or our upcoming iPod and iPhone wireless remote control application (you can see this in action in our video). If you are interested in Internet services such as Internet Radio or perhaps another media library at your office or second home, the bridge can find these as well and give you instant access.
Once the communication path has been established the Bridge can accept almost any format of music storage such as FLAC, MP3, AIFF, Windows media, WAV etc. and convert them into the format best suited for the PWD. This conversion takes place through the Bridge's powerful onboard processor and once completed, the raw musical data is sent to the internal Digital Lens.
The built in Digital Lens
The Digital lens is the key to the success of the Bridge. Without it, the type of transmission and the quality of the data would have a major impact on the sonic qualities of the music. To date, no one has gotten this part right. All the other attempts at transferring data over a network have been compromised at best. High level of jitter, errors and improper formatting for best sonics plague every system we have examined to date.
The built in Lens on the bridge gets it right. A Digital Lens is a device that takes any quality of digital audio data and focuses it to a single, perfect point of data. The Lens does this with the use of a very large digital storage tank (memory) coupled with a jitter free set of asynchronous (disconnected) clocks to output data to the Lens in perfect I2S format.
This means that regardless of how the musical data is sent, via the internet, the network or through the PerfectWave Transport from a CD or DVD, the quality of the data reaching the PWD is the same. Finally, a system that does not care how the data is sent or stored has arrived as the world's finest sounding music server ever built.
The net result of these technological marvels is something to behold. The beautiful full color touch screen on the PWD gives you a great user interface. The Bridge handles data from any storage device you own or accesses music from anywhere in the world, and the internal D to A processor of the PWD converts that digital data into analog music that is warm, natural and musically satisfying beyond your expectations.
Front panel accessible features
Now that you have digital audio data entering the PWD, either through its PWT partner, an external digital source, or the internal network Bridge, it's time to control that data through the many options available on the front panel touch screen.
Sample rate converter
CD's are all recorded at a fixed sample rate of 44.1 kHz and uses 16 bit words. Other media, such as SACD, DVDA and HRx, are recorded with either the same or higher sample rates and anywhere from 16 to 32 bits, depending on the media and author.
It is technically possible to raise any sample rate and bit rate to a higher level through the use of a sample rate converter (SRC). These devices are amazing number crunching mathematic marvels that have been used since the beginning of the CD. They perform their magic by what is known as data manipulation. Their principal value is to reduce jitter, increase bit depth and sample rate so subsequent digital filters can sound better.
The PWD has one of the most sophisticate SRC's made providing 6 choices of sample rate improvement through the front panel touch screen. We included this sophisticated SRC for two reasons: it is expected and in some cases, beneficial. We also included a way to defeat the SRC.
This may all sound very strange as we have become used to the idea that "more is better". If 44.1 kHz is good, then surely 88.2 kHz is better and 192 kHz is the best. In some cases this is true but if you have a chance to audition the PWD and spend some time with this marvel you may discover that the ability to bypass the SRC is perhaps better in many cases.
SRC's manipulate data to do their work. DAC designers of nearly every company, including PS Audio, use them to lower incoming jitter and add features to the front panel. But years of research and a lot of engineering have demonstrated to us that while effective, use of the SRC can be a mixed bag.
We labeled the SRC bypass as "Native Mode" because it allows you to bypass completely the SRC's data manipulation and listen to the raw data as it is sent natively from the source. In most cases, Native Mode sounds far superior to any of the SRC choices, including 24 bit 192 kHz.
This is a stunning advancement in DAC technology that the implementation of the internal D to A processor on the PWD is good enough to permit the native 44.1 kHz 16 bit to outperform the upsampled 24 bit 192 kHz from the SRC.
This feature is easily audible. For example, when using either the Bridge or the HDMI I2S inputs on the PWD there is no jitter to eliminate and so there is no technical need to use the SRC. Running the data through the SRC is sonically inferior to bypassing the SRC and it is an easy and demonstrable test to make. Simply switch between native and 44.1kHz to see. Or go the other way and switch between Native mode and 192 kHz.
The SRC is a valuable feature when the source you are using is of rather low digital quality such as that from an Apple TV, low cost CD player, Squeezebox, Sonos or third party network enabled system.
The PWD offers great flexibility for any source attached and once you hear a high quality source played through our exclusive Native Mode, you won't ever consider going back to a DAC with a SRC in its path.
Every D to A processor made uses both a digital filter as well as an analog filter to get the audio as close to the analog signal the recording engineer started with. The digital filter is a part of the DAC and the analog filter is a part of the analog output stage.
All filters are "double edge swords" meaning they have both good and bad traits. The good is that they eliminate unwanted noise and digital artifacts that would wreak havoc on the music were they to remain. The bad includes the damage they add to the music when they perform their functions which include phase shift, ringing and pre-echo.
To understand the complex world of filters we'll need to take a brief journey back in time to the beginning of the CD player and DAC. In the early days of CD players and DACS digital filters were in their infancy. These filters were extremely steep "Brickwall" style filters which means they kept the audio portion untouched and removed everything above the audio very rapidly.
These filters were so technically sophisticated that up until a year or two ago they have all been essentially the same for the last 25 years. Unfortunately, these filters have a dark side and that side of them contributes to an unnatural presentation of the music that is often referred to as the "digital sound".
Audiophiles have known that "digital sounds digital" and while progress has been made, rarely has any digital audio system approached the musically natural performance of the best analog setups. This class of filters is partly to blame.
Known as Linear Phase Filters their strongest attribute are, as their name implies, the lack of phase shift in the audio band. A phase shift mess with harmonic overtones in a time related sense and contributes to an unnatural presentation of the instruments. These Linear Phase Filters solve that problem but add another: pre-ringing (sometimes referred to as pre-echo).
Imagine an echo occurring before a musical note rather than after the note. This is the effect of pre-ringing and it is extremely unnatural. In fact, we understand now that this induced echo is more damaging than even a little phase shift.
Minimum phase and aporizing filters
Up until a very short time ago, there was no cure for the pre-ringing "blues". But recently a new class of filters has emerged called Apodizing filters and these are able to completely eliminate the pre-ringing of the filters and do so with minimum phase damage to the upper octaves of the music.
So natural are these filters that they just had to be added to the PWD. On the front panel touch screen of the PWD we have made available 5 separate filter choices and among those choices are several Minimum Phase Apodizing filters along with several Linear Phase filters.
We offer these filter choices because our experience has shown that different digital sources sound better with different digital filters. The PWD will actually memorize each of the filter choices for each of the inputs so when you choose your favorite filter it will always come up to optimize the particular input you have selected.
The 5 filters available on the PWD are:
- Linear phase 'soft knee filter'
- Minimum phase 'soft knee filter'
- Linear phase Brickwall filter
- Minimum phase apodizing filter
- Linear phase apodizing filter
One of the handiest features on the PWD that will see a great deal of use is the polarity (phase) control. This touch screen option (available on the remote as well) allows users to select normal or inverted phase for every input and for every performance.
It is common knowledge that sources and music have seemingly no standard for absolute polarity. This fact is easily demonstrated by switching polarities on the PWD as the music plays. Many Audiophiles mark their discs in phase and out of phase and are very careful to select the proper phase before playing each disc.
Some CD players and sources themselves invert phase so that a disc you believe is inverted actually is correct played on a specific device and incorrect on yet another. To fix this problem you can assign each input on the PWD to switch to the proper polarity when you activate that input.
How many times have you wondered what was connected to "Input One"? A common problem with any preamplifier or control center is the difficulty of knowing what is connected and remembering them all. Certainly an even greater problem is when someone else, unfamiliar with your system, goes to switch inputs they haven't a clue what is connected where.
To solve this age old problem the PWD features an easy to use input naming scheme. Switching to the keyboard screen on the PWD accesses a nicely laid out alpha numeric keyboard that allows you to name any input anything you wish. It's a terrific feature that is hard to live without once you've had a taste of this convenience.
Inside the PWD itself
Inside the PWT is an amazing piece of engineering that features the latest in technology coupled with parts quality and circuitry of the highest order.
The heart of the PWD is a Wolfson WM8741 stereo differential DAC, one of the latest generations of high-end DACS in the world. The extraordinary low order modulator and multi-bit DAC architecture found in the WM8742 achieves low out-of-band noise and world-class linearity for outstanding sound quality.
The DAC displays characteristics typically associated only with extraordinarily expensive high end audio products including group delay, phase and latency, impulse response and transition band roll off. These features significantly reduce pre-ringing and give maximum insensitivity to clock jitter.
PS Audio's move to the Wolfson family of DACS is a major shift for the company. Formerly, in award winning products like the DLIII DAC, PS Audio engineering featured the Texas Instruments' family of multi-bit DACS. The shift to Wolfson is a result of hundreds of hours of listening and evaluating in the sound room and the Wolfson family, the first of a new generation of DACS, trounced the TI parts which are the last of TI's older technology.
One of the loftier goals of the PerfectWave series was to build a product that is "pre-tweaked" and would be a difficult challenge to modify for better performance after purchase. PS Audio products are often modified by aftermarket modification services because of their robust engineering and liberal warranty policies that encourage modifiers to "have at it". We're proud that so many excellent aftermarket modification services use our products as their platform of choice, but we wanted to challenge these innovative entrepreneurs with the PerfectWave series.
In the analog section of the PWD we went all out and spared nothing. First we eliminated all the surface mount parts in the signal path. Years of listening have confirmed for us the surface mount capacitors and resistors sound inferior to the best "through hole" passives. In our more affordable products surface mount parts help keep costs down and sound great. But when it comes to the PW series we were unwilling to budge even a little.
Every component is hand chosen. Resistors are the best in the world PRP PR9372 audio resistors. Power supply capacitors are hand selected Nichicon and Panasonic low ESR types.
The audio path is, of course, completely direct coupled from input to output but there are a few audio capacitors needed in ancillary positions and here we chose the highly regarded Nichicon Muse Audio caps.
In the ever important analog power supply, large transformers handled by discrete Jung regulators proliferate the analog circuit board.
Because the PWD is a no-holds-barred high-end DAC we made sure there were absolutely no integrated circuits or op amps of any kind in the signal path. None. Every component is a discrete proprietary audio design developed and refined over the last 35 years of audio design expertise and experience.
Outside the PWD
The chassis of the PWD is a metal sculpture that rivals the best ever built. A combination of aluminum and steel, the PWD weighs in at 20 pounds of elegance and beauty. The top cover is a hand painted, hand polished piano black cover that has been lavished over for hours.
When you receive your PWD, you'll find a pair of soft white gloves to pull the unit out of its protective cotton sleeve and unveil its beauty. Every person who has had the opportunity to see a PerfectWave in person has the same initial reaction: they reach out and softly caress it's finish and admire its beautiful lines.