PS Audio PerfectWave DirectStream DSD DAC

DirectStream is one of the most remarkable DACS ever built. Hand written, discrete, perfection based conversion that uncovers all the missing information hiding in your digital audio media for all these years. CD’s, downloads, high-resolution PCM or DSD based media are expertly upsampled in the DirectStream to ten times DSD rate and output as pure analog directly into your amplifier or preamplifier.

Pure DSD done right

Classic PCM based DACS, including many of today’s DACS that can also process DSD, tend to cover up some of the subtle musical details buried deep within digital audio music; a problem inherent in their architecture. DirectStream solves this problem by employing a pure DSD single-bit approach for both PCM as well as DSD media. This means that your entire library of music can finally reveal all the music and subtle low level details buried deep within its core. Imagine going to a recording studio and listening to a master tape of any recording made. This is the experience DirectStream provides its owners who enjoy a renewed sense of enjoyment and discovery when listening to everything in their library: CD’s, downloads, DSD.

In 1981, music was reproduced exclusively on analogue-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 analogue. 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 analogue 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.

Fundamentally better

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 a 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 pah 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.

Hear more than you ever imagined from 

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 and downloads 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.

Physical

Unit Weight 22 lbs [13.5 kg]
Unit Dimensions 14” x 17” x 4” [ 36cm x 43cm x 10cm]
Shipping Weight 31 lbs [19 kg]
Shipping Dimensions 20.5”x 24” x 10” [52cm x 61cm x 25cm]

Power requirements

Input Power Model specific 100VAC, 120VAC, or 230VAC 50 or 60Hz
Power Consumption 30W

Digtial audio inputs

I2S(2), Coax, XLR Balanced, TOSLINK, USB, Network Bridge slot

Sample Rates

I2S,S/PDIF, and USB -- 44.1kHz to 192kHz 16bit, 24bit, DSD 64, DSD 128
TOSLINK – 44.1kHz to 96kHz 16bit, 24bit

Analog Audio Output

Connector RCA/XLR Unbalanced /Balanced (X2)
Output level, low 1.41 Vrms(+5BV)/3.15
Output level high, maximum 2.81 Vrms (+8dBV)/5.3 Vrms (+12dBV)
Output Impedance 100Ω/200Ω
Frequency Response 20-20KHz +/- 0.25dB
THD+N @ 1KHz (full scale) <0.03%
Output Stage Passive audio transformer, fed by high current, high speed analog amps producing double rate DSD.

Data Handling

Format PCM or DSD
Sample rate (PCM) 44.1kHz, 48.0kHz, 88.2kHz, 96.0kHz, 176.4kHz, 192kHz
Word length (PCM) 16b, 18b, 20b, 24b
Data rate (DSD) Standard (2.8MHz) or Double (5.6MHz) DoP on all inputs as well as raw DSD on I2S inputs
Input jitter reduction effectively 100%, residual immeasurable. No input PLLs, FLLs.
Input Processing 170MHz
Signal Processing 50MHz
Synchronous Upsampling, all inputs 28.224MHz
Digital Processing S/N ration >146 dB
Digital Volume Control Zero loss of precision
Analog Conversion method Delta Sigma (DSD) Single-bit double rate

I2S Digital Input

Connector HDMI
Format PCM or DSD. DoP on all inputs as well as raw DSD on I2S inputs

USB Digital Input

Connector USB “B” Type
Format PCM or DoP v1.1 (DSD over PCM)
Transfer mode Asynchronous

Please read the excellent reviews 

Please click for Audiophilia Review

PS Audio achieves the impossible

The DS is a game changer; I think it has caused the ‘war’ between DSD and PCM to be on hold or mute for most of us, and above all hold your horses before buying expensive high-resolution PCM files or DSD. That alone is a major accomplishment.

Bit perfect Review

One of the most detailed reviews written

The DirectStream’s sound is non-fatiguing in an almost tube-like way. It is smooth and relaxing. Surely, you tell yourself, it must be sacrificing detail to deliver this. But no. With recording after recording, the DirectStream presents layers and layers of detail in such a way as to produce a sound which is very easy to listen to, and with a low fatigue factor, even with CD sources. As someone with very little tolerance for the fatiguing nature associated with CD, I find this to be a most appealing characteristic.

6 Moons Review

The best way we've yet encountered to turn digital into music

But what happened now was beyond our expectations. Maybe we had been lulled into a bit of been-there-done-that reviewer fatigue but the DirectStream’s handling of this CD became a rude wakeup call and put us back on edge to eat crow. Damn, the performances of the various groups and soloists were so real and at such dynamic range, it was hard to believe that the source material was a simple 16/44.1 Redbook CD.

AudioStream Review

There was an amazing sense of purity to the DirectStream's way with music as if everything and anything extraneous had been stripped away.

Even at low listening levels, music retained its character with no sense of the sound washing out. For those people looking for a direct-to-amp DAC/Digital Preamp, consider the DirectStream a solid contender.