The start of the 30-year war
In 1981, music was reproduced exclusively on analog-based turntables and tape decks with limited dynamic range.Despite the very listenable music coming through those grooves, the audio world wanted more: greater dynamic range, lower noise, extended frequency response. No wonder that when, in 1982, Sony and Philips announced they had achieved “Perfect Sound Forever,” music lovers around the world waited in eager anticipation of analog’s promise finally fulfilled. Unfortunately, those early CD’s sounded less musical than analog. In some cases, much worse. The launch of the PCM-based Compact Disc would set in motion a 30-year war amongst Audiophiles, decimate the analog format, cover up subtle musical details for decades and turn the music and audio industries upside down–and not necessarily in a good way. There had to be a better way to fulfill the promise of analog’s century of dominance for sounding like music and PCM would not be it. That answer is DSD.
The poor results of the first CD’s might not have been a problem if Sony and Philips had waited another decade, passing over the classic PCM delivery system in favor of PDM (DSD). The problem is the PCM decoding process itself: whether a classic ladder-DAC or more modern multi-bit Sigma-Delta type, most PCM playback processors mask some of the subtle cues in music. Fortunately, music’s details have been more faithfully recorded than we ever suspected, but the cover-up of those recorded details has been with us for more than 30 years. Happily, the missing musical information is still buried deep within our audio libraries–waiting to be revealed. In order to extract everything hidden in PCM recordings, a completely new processing method is needed.
Pure DSD is the answer
Put DSD into DirectStream, you get DSD. Put PCM (how CD’s are recorded) into DirectStream, you get DSD. DirectStream converts all digital inputs, including PCM, to pure 1-bit DSD, in an elegantly-simple path. In the process, the PCM feed becomes more linear, less edgy, and never-before-heard musical details are released from all digital audio recordings. Billions of CDs and high-resolution downloads worldwide will gain new life, and be saved from obsolescence. There’s a notion floating around high-end audio circles that DSD may be nothing more than a passing fad. In fact, we would suggest the opposite may be true. PCM based music decoders are nearing the end of their lifecycle in favor of a significantly more musical sounding format, DSD.
A better format
DSD is a high sample rate single-bit format while PCM is a lower sample rate many-bit format. DSD sample rates are 64 times higher than those used to create CDs and the output of a DSD stream can be placed through a simple filter to produce pure analog ready to feed your audio system. PCM, on the other hand, can produce great sounding music but to do so requires a very complex and technically daunting conversion process to produce something you can play on your system. Sometimes the simplest path is the best sounding one. DSD is a far more analog-like encoding and decoding process than classic PCM. In fact, most modern A/D converters (used to make the recordings) are DSD based already and that movement is growing. There are millions of PCM based recordings that will be in our libraries for years to come, but with the introduction of DirectStream, you no longer need listen to them with a PCM based processor.
The secret is in its simplicity
Take a look at this comparison diagram: on the top is a block diagram of one of the best PCM-based processors in the world. Notice the circuitous path taken by the audio data stream to the output of this converter. Then look at the pure simplicity of the DirectStream. The PCM processor’s tendency to mask music’s subtle details is largely due to its complex needs, and the technical requirements of PCM processors.
Converting PCM to DSD
Converting PCM to DSD can be an easy exercise using any number of computer software programs. Converting PCM to DSD properly, and in such a way as to reveal missing details in the music, is a serious technical challenge. To handle this properly DirectStream utilizes 66-bit fixed-point FIR filters, eliminates headroom issues common to PCM, flattens noise response in the 20-100kHz region, uses coefficients optimized for best sound rather than faster processing speed and optimizes hardware-specific operations not possible in software. Unlike other processors available today, DirectStream unifies all inputs (PCM or DSD) at 20 x DSD, then uses a true single-bit double-rate DSD core engine. True DSD core engines (compared to the standard multibit Sigma-Delta converters followed by random lower quality multibit converters) offer advantages in simplicity, linearity, and in analog-like overload characteristics that avoid PCM’s hard clipping potential and a PCM processor’s propensity to mask subtle details.
Pure 100% single bit DSD based D to A Converter
Most of today’s sophisticated DACs are IC based instruments using off-the-shelf-chips that are Multi-bit Sigma-Delta based designs. While these are relatively simple to design and produce, they don’t often give the best results sonically. Because they are one-chip systems compromises are made in their architecture that found in DirectStream’s custom based architecture. DirectStream takes both PCM and DSD, upsamples the data and converts to single-bit DSD and then outputs pure music regardless of input format for the data. The results of this design can be heard in increased musical information presented to the listener at every opportunity.
Purely passive output stage
Most modern DACs use some form of active tube or solid state output stage to amplify, filter and drive the DACs output. DirectStream takes a different approach: passive. In one of the simplest, elegant and musically correct executions of an output stage, high-speed class A video amplifiers are used as the final switch for the single-bit, double DSD output of DirectStream; feeding a high-performance passive audio output transformer. The transformer is specially designed to act as both the galvanic isolation between the DAC and the outside world as well as the primary low pass filter required to present a perfect, low distortion, low noise output signal. When you listen to DirectStream you never are accosted by added bright, hard glare in the music as happens with many active designs. Instead, clean, pure music flows from the DirectStream directly to your preamplifier or power amplifier.
Resolution perfect volume and balance controls
Designer Smith perfected a 100% bit-perfect volume and balance control that’s built into DirectStream, enabling users to control the output level when feeding directly into a power amplifier or preamplifier. That the volume control is completely bit-perfect means there is no loss of resolution for any volume setting, a feature unique amongst the majority of DACS in the world today. The ability to eliminate the preamplifier in the system without any resolution loss is a major benefit to DirectStream’s outstanding musical performance.
Simple, direct signal path with only one master clock
Typical high-end DAC designs use more than one master clock as you can see in the drawing we provided on the Overview page. There are often separate clocks for USB, Audio and others, causing major headaches for system designers trying to synchronize the clocks. DirectStream obviates the problem by basing the entire design on one master clock of extraordinarily high quality. Used is a low phase noise, low jitter clock designed for DirectStream by Crystek. Using this advanced approach the need for synchronization is eliminated, jitter levels are reduced and music is delivered with a clarity rarely heard.
Immunity to jitter from sources
Sources have always had a major impact on sound quality with DACS. Transports, computers, CD players, cables all make a significant impact on performance into a typical DAC. This problem has been significantly reduced with DirectStream. Now, for perhaps the first time, sources of just about any quality and jitter level sound nearly identical. For example, you can take a cheap $30 DVD or CD player’s digital output, connect with DirectStream and have sound quality unthinkable for such a poor source. Performance levels no longer are dependent on the quality of source or connections; certainly not to the degree they have been in the past. Yes, cables and sources still make a difference, but with DirectStream that difference is reduced to nearly background noise. Whatever you use to play or stream your music now sounds as good as it gets.
Asynchronous high-speed USB
DirectStream can match up to either a computer or a home network. If a network connection is desired, there’s is the optional Network Bridge available that slides right into the rear panel of DirectStream and adds an additional input. You can also connect directly to your computer via USB. USB communication, if handled properly, can have every sound quality advantage of a dedicated CD transport or Network Bridge. DirectStream provides a fully synchronous 24-bit 192kHz path for USB based audio. Using a good quality USB cable between DirectStream and your computer, like a quiet MAC Mini, provides an instant media server that can be controlled through any number of handheld devices like an iPod, iPhone or Android using a 3d party controller program. Your music can be managed by iTunes, Bit Perfect, Pure Music or Ammara for ease of use.
A handy feature on DirectStream 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. Sources and music have no standard for absolute polarity, a fact easily demonstrated by switching polarities on the 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 DirectStream 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.
Play directly into your power amplifier or preamplifier
DirectStream offers the ability to play directly into either your preamplifier or power amplifier through either its balanced or single-ended outputs. You can select the optimum gain setting through DirectStream’s setup menu to match your amplifier and loudspeaker’s sensitivity. If you choose to go through a preamplifier, it’s easy to set DirectStream at maximum level (or any level you wish) to match the preamp’s gain. But should you choose to eliminate the extra electronics of the preamplifier, DirectStream is more than capable of driving the power amplifier directly. DirectStream’s unique zero-loss volume control maintains full resolution bit-perfect performance at any volume setting from the lowest to the highest levels.
Hear more than you ever imagined from CDs
DirectStream converts everything to DSD, even PCM before delivering the music to your system. This approach, coupled with careful design, low jitter and a simple and direct signal path has the benefit of uncovering details buried in the music you may not have realized are even there. CDs come alive with subtle details that were never apparent with your older DAC; details you never knew even existed. CDs sound more like high resolution audio than you ever imagined, closing the gap between higher resolution PCM and DSD copies. No longer do you need to consider replacing your current CD library because once you hear what’s truly on your discs, you may not need to consider upgrading to a higher resolution copy at all. Yes, it is that obvious and significant.
Globally recognised, locally handcrafted.
DirectStream is built in the United States by hand. Local manufacturers use sophisticated PCB building machines to populate and test the multi-layer boards used in DirectStream. It takes a number of companies and a lot of skill and equipment to build something this sophisticated. From high tech x-ray technology to place the FPGA IC on the board, to automated pick and place machines to add parts in just the right spots, each of the four PCB’s used to build a DirectStream are built, tested and delivered to our Boulder Colorado facility by handpicked US vendors. The chassis of DirectStream is a metal sculpture that is by far the best we’ve ever built. A combination of aluminum and steel, DirectStream weighs in at 20 pounds of elegance and beauty. The top cover is a hand painted, hand polished piano black high density material that has been lavished over for hours. And has the look and feel of a fine Steinway piano. The PerfectWave series is assembled, programmed and tested at our production facility in Boulder Colorado. 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.
This is a DAC that suits a relaxed style of listening and because great tone is such a huge part of what makes music enjoyable to many, it’s appealing to a vast plethora of music…
What is Clear with these characteristics is that the DirectStream is going to hugely appeal to John or Juliette Vinyl, who do things the old way but want a foray into streaming and digital audio. Or anyone who wants a relaxed sound in digital for that matter. Now is a good time with CD on shaky ground with streaming services soldiering on. It’s consequently the dream DAC and streamer for such people – non digital sounding digital!!!
Forget the old reckonings of the past about insidious edgy treble in DACs as to why your music must spin round and round. That thinking is now as far away as Earth is to Mars. DACs like the DirectStream change all this!
The PS Audio DirectStream DAC is a 5 year old design that, with the latest “Snowmass” release, still competes with the best DACs in its price class. How many DACs can make that claim? Many DACs are user-upgradeable, but very few have received the steady stream of free firmware updates that delivered sound quality improvements – not just bug fixes – that enable the DS DAC to retain its competitive edge. Plus, designer Ted Smith tells me he still has some (albeit shrinking) capacity left in the DS DAC’s FPGA to continue delivering improvements in the future. These include trickle-down findings from the cost-no-object Obsidian “Ted Smith Signature” DAC he is developing. That is a stunning value proposition, and one very few companies can match.
The DS DAC is an intensely enjoyable piece of gear that allows you to connect deeply with your music. Its biggest strength is its ability to make music sound natural and real. Refined tonality, dimensionality, dynamics, and grunt – it has it all. And to my pleasant surprise, this was the first DAC I’ve reviewed where I could optimize the Ethernet input to a level of sound quality close to that of USB.
Did the DS DAC surpass its competition in every attribute? No it did not, but that’s not how I measure success. The DS DAC’s success comes from having earned a spot on the shortlist of any audiophile shopping for a DAC in this price range. And just like thousands of delighted current owners, I fully expect many more will find it to be the one that speaks best to their soul. Highly recommended!
In all configurations I tried, playback from the Memory Player was clearly better than playback from the Mac Mini+Roon. This is an instance where I feel the differences were not a matter of preference. I am sure there are some out there who would prefer the sound of the server, but they would be wrong…. I consistently heard a lower noise floor from the Memory Player and, from that, more air, better definition, and less smearing, which I became aware of only when confronted with its absence.
I also heard better bass from the Memory Player; not more ample bass (or not just that) but truly better in being more foundational and center-of-the-earth, which is musically important even with smaller speakers…
I can’t think of a company I’d be more comfortable hitching my digital wagon to than PS Audio. The DirectStream Memory Player and DAC are, without question or reservation, exceptional products worthy of your serious consideration.
Part Time Audiophile
I feel fairly safe in concluding that not only are these components highly enjoyable to hear and use, but that they are also safely on the cutting edge of digital audio reproduction. And I don’t see that premise changing anytime soon, what with PS Audio’s commitment to free software updates to anyone purchasing the gear. I don’t think the digital audio enthusiast could go wrong with this pair!
I can’t think of a better digital disc player than the PS Audio DirectStream Memory Player and DAC. (Neither of these six figure players will play your DVD-a discs) If I had more than two thumbs to raise I would offer them, it’s that good. The only remaining choice is whether you want silver or black.
Attaining the performance provided by the PerfectWave transport and DirectStream DAC even five years ago would have cost multiples of the PS Audio Duo. This potent, engagingly musical front end will allow you to rediscover the plethora of CDs in your collection with a fresh, more organic and dynamic take. And with the millions of CDs flooding the used market the PerfectWave Transport and DirectStream DAC will be a great musical partner standing by your side for years to come.
Time will tell if and when these levels of performance, flexibility, and luxury will become available for less than $6000. But today, for those who’ve waited for a computer-friendly DAC that offers, with every type of music file, the best musicality of which DSD is capable, the PerfectWave DirectStream may be in a class by itself.
The Absolute Sound
DirectStream’s easily the best DAC I’ve ever heard in my system, making digitally-recorded music sound better than I’ve ever heard it.
Hi Fi PLus
The real magic of this DAC may centre on its handling of PCM material—material the DAC gives greater smoothness, fluidity, dimensionality, and elegance than it might otherwise have had. I don’t mean to suggest by this that traditional PCM playback methods cannot or do not sound perfectly good in their own right, because they certainly can and do. But if PCM playback has an identifiable ‘failure mode’ it might be that PCM files can at times sound a bit flat and 2-dimensional, while exhibiting subtly edgy and/or mechanical qualities that tend to hold the listener at arm’s length from the music. … I will tell you that it makes these sorts of playback problems better—and sometimes eliminates them almost completely.