t rarely happens a company with a narrow specialization conquers another segment of the market so successfully as it happened for American, Boulder, Colorado based company PS Audio.

The specialty, which this company is known of today, are active power conditioners. Unlike conditioners, which only passively filter voltage, PS Audio products actively compensate for its variations, frequency fluctuations, or simply generate a new sine wave.
Today, many companies do it this way, but then it was a pioneering work, which lead to many discoveries - like the fact that the 60 Hz frequency works better than 50 Hz – that inspired successive constructors. Suffice to say that a power supply for Ayon Audio Spheris III actually works in a very similar way as these "AC Regenerators", generating ideal sine wave for tubes. Of course, of a frequency of 60 Hz.

Founded by Paul McGowan (P in the name) and Stan Warren (S), PS Audio has undergone many changes over time. Suffice to say that the State Warren left the company in the early 1980s, and a decade later Paul McGowan also left in order to, along with Arnie Nudell (formerly Infinity Systems), build ultrahigh-end speakers at Genesis Technologies.

Contrary to common association, the PS Audio started its activities from completely different products. It was founded in 1973, and its first product was a phonostage. After that came the time for linear preamplifiers and power amplifiers. As one of the first firm, PS Audio modified CD Players replacing their output stages. One could say that the modern history of the company started in 1997, when after the bankruptcy of the PS Audio Inc. Paul McGowan bought the rights to the brand name and soon after that introduced the power conditioner P300, that was called PowerPlant.

NuWave DSD

Another new chapter in the history of the PS Audio was launched with a special product – a two-box files and CD Player and DVD PerfectWave, later joined by DirectStream. The next inevitable step was adding power amplifiers to the lineup, which was realized with the introduction of BHK Stereo 250 BHK Mono 300.

All these are relatively expensive products. To use some of the solutions developed for them for less expensive products company decided to offer less expensive digital-to-analog converters: DirectStream Junior DAC and NuWave DSD DAC. The latter is really inexpensive, and yet, as it reads in the company's materials, is expected to offer similar sound quality to that of a top DirectStream DAC. Furthermore:

Lessons learned from years of building DACs aided design decisions critical to the mission of few musical compromises.  We believe that one audition of a simple CD, played through the NuWave DSD, will open your eyes to the magic these design efforts have brought.

And than:

Important to both designers would be bringing as much musical detail as possible out of Red Book CDs, and reducing the sonic gap between 44.1kHz/16 bit performance and high resolution PCM and DSD. 

source: psaudio.com

It is not just "another" product, but the one that the chief engineer, Mr. Bob Stadtherr and director of the company, Paul McGowan worked for the past year. As a result of their efforts a DAC was developed, which looks great, features a solid, sturdy built, and its sound is "tuned" exactly as these two gentlemen wanted it to be. It accepts PCM signal via RCA inputs (up to 24 bits and 192 kHz) and TOSLink (up to 24 bits and 96 kHz) and PCM up to 24/192 and to DSD (up to DSD128) via USB and I2S. The latter connection uses HDMI link, so one can use wide range of available cables of this type. Via USB input DSD files are sent in the DoP format, while the I2S accept its native form.

The device's operation is to be as simple as possible, so it automatically recognizes an active input and features a minimum set of manipulators - four LEDs indicating the active input, two indicating whether device receives PCM or DSD signal and there are two buttons for manual input selection. No display, no information about the sampling frequency, no volume control nor headphone output. It does feature, however, a FPGA for input signal, a passive filter on the D/A converter output and the class A output circuit. NuWave features both, RCA and XLR analogue outputs.

Recordings used for test (a selection)

CDs

• Now the Green Blade Riseth, The Stockholm Cathedral Choir, Proprius/JVC XRCD 9093, XRCD2 (1981, 1993/2001)
• Johann Sebastian Bach, Three Works For Solo Harpsichord, BWV 974, 971, 831, harp. James Weaver, Smithsonian Collection of Recordings ND 0383, CD (1990)
• Kenny Drew, Undercurrent, Blue Note/Audio Wave AWMXR-0024, XRCD24 (1961/2010)
• Laurie Anderson, Homeland, Nonesuch 524055-2, CD + DVD (2010);
• Megadeth, Dystopia, Universal Music Japan UICY-15449, SHM-CD (2016)
• Megadeth, Fatal Illusion, Universal Music Japan UICY-5130, SP CD (2015)
• Paul Desmond, Desmond Blue, RCA Victor/BMG 6638982, „Bluebird First Editions”, CD (1962/2002)
• Thelonious Monk, Brilliant Corners, Riverside/Universal Music Japan UCCO-9220, „Jazz The Best. Legendary 100 | No. 20”, CD (1957/2008)

Music files W czasie odsłuchu skorzystałem z plików PCM 24/44,1, 24/96 oraz 24/192, a także DSD, z szerokiej gamy stylów muzycznych i wytwórni.

Japanese issues available at

If the name of a device includes supplementary information, in this case, "DSD", we are faced with one of two possibilities: the manufacturer indicates to its specific feature, that makes different or similar to other devices, or indicates its main feature, the one that is most important to him. I think in this case it was the former and the goal was to point attention to the fact that a relatively inexpensive device is capable of decoding a DSD signal. Or maybe the manufacturer combined both options in this particular device because it offers a sound characteristic for DSD files and SACD discs.

If I had to guess, I would say that it was about offering the richest and most tangible sound. These are two of many features, that make recordings encoded in the DSD so appealing to the taste and sensitivity of music lovers. These are very important features, because they make a performance believable. That is why the PS Audio Converter delivers a very attractive and enjoyable performance. The first evening with this DAC I spent listening to music using HiFiMAN HE-1000 V2 headphones, that are very transparent, but at the same time very rich sounding. The last Megadeth Distopia album sounded with them really nice, without any harshness and wheezing, despite the lack of dynamics and deep compression.

What is responsible for that is this specific, to this type of product, ie. DSD oriented, way of shaping of the leading edge. It is, or at least appears to be rounded. Along with a slight warming up of treble and adding an emphasis to mid-bass results in this type of sound. By this type I mean so wonderfully complex and coherent internally and very "humanly". Once, in a similar manner people described sound of most tube amplifiers, for example of McIntosh, QUAD and Kondo, and this is a good clue. Here, however, it's not about the classic warm-up of the sound. Performance is very pure and carries a lot of energy that is lost when sound is actually warmed up. It is no coincidence that warm sounding devices are often referred to as lacking energy and playing is a slowed way.

NuWave DSD presents a way of how to do something similar, but without extinguishing performance's energy. I would even say that the presentation is slightly boosted - this is why it is so impressive, so catchy. There is a lot of energy in the sound that has also a large mass, which creates an impression of intimacy and naturalness of the performance. This impression is even stronger because of emphasis placed in the midrange area and pushing the foreground closer to the listener. When listening to Megadeth it might not be so clear, but with classical and jazz music it becomes obvious.

Because, for example, harpsichord on, released as part of Smithsonian Collection of Recording, album called Three Works For Solo Harpsichord by Bach, with NuWave was presented closer to me, and with the reference DAC and reference CD players there was more air around it. It reminded me the way Amare Music Tube DAC DSD and Kronos Sparta turntable presented music .

But this modification of the sound was not unpleasant or wrong. I perceived it as a re-interpretation of what is included in the recording, and it's not just about CDs, but also files. Without comparison with other devices it will be easy for us to assume that this is the right way, the right sound. Turntables, such as Sparta, modulate sound in a similar way, which works very well for them. I would even say that the most expensive turntables, such as TechDAS Air Force One also go in this direction, but along with that they also offer a much wider perspective, and more even tonal balance.

The fans of DSD encoding claim that it is very similar in nature to that of an analog master tape from which it was copied, and if the registration is made directly in the digital domain (DSD) is it closer to the real events than one encoded in PCM files. I will not elaborate on that, but I will say that my experience tells me that, that indeed, there are some qualities which make the sound obtained with this type of signal very attractive. The DAC under review applies them to each signal, regardless of whether it is sourced from CD, hi-res PCM or DSD file. We must therefore say that the promise made by the manufacturer in the description of the products, according to which the CD will play in a really unique way is really fulfilled. Provided that we agree that this is kind of interpretation to which all recordings are subjected.

But it is really good. Even more so because it is a – relatively, of course - inexpensive DAC. It is well made and it delivers a really good performance, with a strong lower end, sweet top and warm, close midrange combined with very high dynamics. It's a very similar way to build sound to what we know of the more expensive devices, such as Exogal Comet Plus DAC and said Amare Musica. It's not a coincident, since both these companies treat DSD format as THE RIGHT ONE for encoding and playing music. NuWave DAC is much cheaper and still follows the same idea and does it in an equally spectacular way.

What distinguishes it from both above mentioned products, it is mainly slightly lower resolution and not so good definition. There is no shortcut for that, one needs to pay more money to get it. But even at this price level we already get a lot of what the more expensive devices have to offer. I.e. naturalness and softness that characterize live sound. That's not all, there are other elements of the natural sounds that are not fully realized here, but it does not change the fact that it is a very good performer.

Especially when we use it to play high resolution files. There is no information available on conversion of PCM signal to DSD in NuWave DAC, which is clearly described for other devices. And yet, the 24/96 and 24/192 files sounded similar to DSD files, even the attack was formed in a similar manner. Just in this case, DSD files had even higher dynamics and were more tangible than PCM ones, but this may be caused by designers' – perhaps even subconscious – preference of Direct Stream Digital.

However, regardless of what type of file I played, as long as it was a 24 bits one, it sounded more relaxed and less muffled than a CD. This is the case, when for owners of this type of DAC it actually pays to invest in the high resolution files, preferably DSD. A sound one shall get from them will not be totally different from the CD, it won't be day and night type of difference. One will notice changes, which may seem subtle, but if achieved by replacing a system with a higher quality, more expensive one, one would have to pay a lot of money for it. Here you can just buy a hi-res file rather than rip a CD and the effect will be similar – fuller, richer, more spacey sound, more poignant sense of the performers' presence and thicker, blacker background.

Summary

There is not much to add to what has been already written. This is a beautifully made device featuring a lot of inputs offering a beautifully voiced - within a certain aesthetic - sound. The device delivers an attractive performance that will help systems at this price level sound in a more natural and emotional way, and in bit more expensive systems it will not lower their sound quality and even allow them to sound more "analog" (quotation was used deliberately). RED Fingerprint.

The PS Audio NuWave DSD is digital-to-analog converter with a fixed voltage output (ie. not adjustable). Its proportions are chosen so that it seems even smaller than it actually is. The front wall, with rounded side edges, has a width of 210 mm, exactly half of a classic size device. DAC is also not high, but relatively deep, measuring 360 mm. And it is heavy, which is particularly surprising.

The enclosure is made of aluminum with an acrylic top. Front features only few elements which creates an impression of order, what was probably designer's idea. There are six blue lights, four of which indicate the selected input and the two signal type - PCM or DSD. The unit automatically synchronizes with an active source. We can, however, also select input manually using two buttons. On the left side there is an illuminated logo and that's it. Thus, no information about the sampling rate or word length. Housing is available in black and silver.

The rear panel of the device is more classic, so to speak. In addition to the IEC mains socket with a small mechanical switch (manufacturer recommends leaving the DAC on all the time) there are also digital inputs and analog outputs. There are four digital inputs: USB, I2S, TOSLink and RCA. I2S is unusual, because it utilizes a HDMI socket. It makes it easy to acquire a high quality cable of any length for this connection. Other companies using this format for the transmission of data use Ethernet jack (Ayon Audio, Pro-Ject, Accuphase etc.).

All components are installed in this device on its “back". Unscrewing the bottom will allow you to see that the transformer and PCB are bolted to the upper wall. It is made of aluminum, but from the outside it features a black acrylic sheet which has a decorative function, but it also dampens vibrations.

The RCA input accepts PCM signal up to 24/192, TOSLink up to 96 kHz, and USB and I2S the PCM signal up to 24/192 kHz, also DSD64 (2.8 MHz) and DSD128 (5.6 MHz). USB input operates asynchronously. All incoming signals are routed directly to the FPGA in a "Native Mode", i.e. without upsampling and interpolation. This chip detects the sampling frequency of the input signal, overclocks it, hence reducing the jitter, and filters it. The chip comes from Xilinx.

The USB input features XMOS chip, which was used also in the PS Audio top DAC, DirectStream. The DAC chip is a well known and respected ESS Hyperstream 32, adopted by engineers to work in this particular system. It features passive filters in the output, rather than active - a solution used also, eg. by Polish company Ancient Audio. Only after we have them there are gain and buffering stages, composed of integrated circuits and transistors. The signal is transferred in its balanced form. The analog section operates in class A, there are no capacitors in the signal's path, and its frequency response riches up to 60 kHz. Interestingly, the integrated circuit used here is an inexpensive, popular NE5532, surface mounted, like the rest of the elements in this section.

The power supply is based on a really large toroidal transformer. It was placed in the front part of the casing, so it was not necessary to use long wires with a signal – inputs sit directly over PS boards. The power supply features seven independent voltage regulators with fast Schottky diodes and capacitors with total capacity of 15 000 mF.

Parameters (according to manufacturer):

Output signal (RCA | XLR): 2.8 V | 5.6 V
Output impedance (RCA | XLR): 100 Ω | 200 Ω
Frequency range: 10 Hz – 20 kHz (+0/- 0.3 dB)
THD:
- 1 kHz, 0 dB FS: < 0.01%
- 20 Hz -20 kHz, 0 dB FS: < 0.2%
- 1 kHz, -10 dB FS: < 0.01%
Noise: <-80 dBV
Weight: 5.4 kg
Dimensions (D x W x H): 360 x 210 x 61 mm
Power consumption: 15 W