PS Audio PerfectWave DAC
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 apodizing 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:
1. Linear phase 'soft knee filter'
2. Minimum phase 'soft knee filter'
3. Linear phase Brickwall filter
4. Minimum phase apodizing filter
5. linear phase apodizing filter
We have also added a feature for the filters known as "Auto". Auto filter chooses the best selection of filter based on the sample rate chosen. This means that as you play different sample rates, such as when you switch to USB and the sample rate goes to 96kHz 24 bits, the appropriate filter is automatically chosen for you. The auto filter chooses one of the five available filters.
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.Touching this control is the same thing as reversing the loudspeaker connections of both loudspeakers (+ to -) at either the amplifier or speakers.
All live acoustic music is in absolute phase but some recordings may accidentally be made inverted and should sound more realistic and pleasant when you correct their phase with the switch.
When a playback system is in absolute phase (polarity) when the transients of the reproduced performance are in sync with the transients of the live performance.
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.
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.