About three years ago, Kevin, the founder of Fu Sheng Audio based in Guangzhou, introduced me to have a listening experience with a Pureaudio DAC30. Later on, I wrote a review after the audition about the new way of reproducing high-resolution music files with this DSD DAC featuring a dedicated HDMI interface. With the passage of three years, different kinds of media players have been coming along, none of which is capable of real hardware-decoding native DSD music data. Kevin, together with several senior audio experts and friends, made up their mind to design and manufacture the best-integrated amplifier in China---the NSR Model One. As stated before, the NSR Model One offers a dedicated HDMI interface, and I feel obliged to explain why it is essential to use the HDMI Interface. The HDMI interface is especially critical when it comes to playing music on SACD or decoding and playing DSD ISO files. Some people may ask why it is needed to hardware-decode the DSD file over the HDMI interface since it sounds better with the 24bit/96kHz or 24bit/192kHz music files. I have to admit it is true, but the real recordings are hard to obtain, whether on the internet or from the record companies. SACD is still the most wealthy high-resolution music source, and there are three ways to enjoy the music on SACD:
First, one can play with an SACD player. Most integrated SACD players, however, are not capable of decoding and playing DSD music files. The OPPO Blue-ray player can help decode native DSD data. Still, the paired AV amplifier usually converts most if not all the DSD data into PCM format before decoding, which compromises the sound quality.
Second, one can play on the computer. But Computers cannot play SACD directly, so one has to break the SACD to get iso files and play the iso files with software like Jriver, Jplay, Foobar2000, etc. Some media players on the market can support DSD data yet only in DIFF, DSF, or AIFF format; ISO files remain an unsolved problem. In the decoding section, S/PDIF interface has never designed for DSD data transferring, be it electrical (Cinch) input or balanced optical (Toslink) input. USB 2.0 is the last choice, but the problem is the USB audio 2.0 only supports PCM format, and what makes things worse is the audio driver in Windows system or Mac Os system does not support direct DSD transferring over the USB. To solve the problem, people have developed a technique called Dop (DSDover USB), and it works in this way: to input the DSD data into a PCM structure, and transfer the transformed signal over the on-board USB drive. In other words, the method is camouflage from DSD format to PCM format so that the signal could be transferred over the USB, and after transferring the signal takes off the camouflage to be decoded and played back. Unfortunately, some musical data fail to take off the camouflage and are decoded as PCM format. That some DSD data is converted into standard PCM format on the computer makes the Dop method even more meaningless.
In most cases, People have to use Sony/Philips Scarletbook on the computer to extract DIFF file (usually four times larger than WAV files)from iso music files. Audiophiles are pursuing an enjoyment of music, not the headache, by exploring the usage of sophisticated technology. So even if the sound they will get from the exploration is pretty fascinating, it is like a mirage for many of them. From where I stand, the more easy operation will be far better, and all that is needed is a remote control. The first thing is to buy an OPPO blue-ray player and play the ISO files found on the CDs. Without converting any format, the native DSD data will be transferred over the HDMI interface, which is the only interface able to transfer DSD data. The HDMI interface receives data in I2S mode and separates the data, clock, and the synchronized signal to avoid distortions from jitters. Theoretically, we could transfer the native DSD signal with the lowest distortion only if we have a robust HDMI interface. And last, we could wrap it up to get a preamplifier featuring an HDMI interface. But Kevin thinks bigger than any of us; he wants to integrate the preamplifier and amplify into a single chassis, and the decoded signal could come to drive the speakers directly. So here comes the integrated amplifier---the NSR Model One.
NSR---A New Star in China Audio Industry
As the very first integrated amplifier by NSR, the Model One defines the state of the brand’s technical art and know-how. The NSR Model One is a New Generation of Integrated Amplifier featuring a digital interface plus a pure analog, redefining the integrated amplifier like no other. The NSR, short for “Natural Sound Research,” is their registered brand and the company is planning to release a series of products in the days to come: NMA All-in-One Integrated Amplifier (80W output ), NMP Media Player, NDP Preamplifier, NS380, and NS160 Power Amplifiers, NPH phono and Swing shelf Speaker, etc. Ever since the NSR Model One was introduced, it has been critically acclaimed by a good many audiophiles though it actually was selling with no profits at all.
Kevin, head of the design team, is never a tonally oriented designer, and this is evident in the Model One. He has been dedicated to delivering a kind of clean, natural, dynamic, and transparent sound. To reach this audio goal like never before, he spared no expense and effort designing and manufacturing the masterpiece---the NSR Model One. The prototype of the Model One came out five years ago with separated structures. After five generations of painstaking refinement and outright breakthroughs, the Model One, as we see today, is nowhere. Browsing through the website of NSR http://www.nsraudio.com, we could read the articles like “The Birth of a Miracle” and other audiophiles’ reviews about the NSR Model One. All those reviews or remarks are flush with praise for its breathtaking capabilities to drive the Dynaudio loudspeakers: the Evidence Master and the Consequence Ultimate Edition. The latter usually needs a high-level output power amplifier to operate correctly and flawlessly. That the 100W NSR Model One effortlessly married with the Dynaudio Consequence Ultimate Edition while delivering a precise and natural, powerful, and vigorous sound evidently startled every one that had the audition experience.
Unbeatable Sound Quality
But there is another problem. Most users are likely to use CD transport to pair with the Model One over the AES/EBU interfaces. This method only brings 60% percent of the outstanding capabilities of the Model One. What a shame! That’s why I recommend using the BDP-LX88 flagship blue-ray player to pair with the Model One over HDMI interface. The unsurpassed sound quality delivered this way. Just let one rediscover the great value hidden deep in DSD music files.
The Mbox player I have been listening to is also capable of recording and playing back ISO music files, the sound rendered, however, could never give me a feeling of “real transparency” due to the stray interference. It was as if there was a veil covering the sound. Ever since I owned the Model One, things have become different. Whether playing the SACDs or DSD ISO files with LX88 blue-ray player, the Model One captures and reproduces the intangible something about music that appears directly to my heart, not just my brain. Over the HDMI interface, the sound distortion and noise are reduced to an absolute minimum. The clear, transparent sound makes me simile as I couldn’t have to hear “veiling” on the sound anymore. The sound of Telarc’s recording is rich and heavy, and it is more powerful on SACDs. If it is not handled well, the recording would sound like roaring without any texture. But it really astonished me that the 100W Model One brings a sound with a deep and wide soundstage and lightning-fast transient response; the highs are not aggressive, the medium is transparent, very clear and detailed, and the bass is clean and precise with amazing clarity. The transparent sound brings one to the concert scene and clearly shows the layout of the concert hall. The ambient detail from Model One’s breathtaking detail retrieval capability is evident throughout the whole frequency. All these resplendent musical performances and sonic achievements come from the 100W Model One. Unbelievable!
A Expansive Set of Inputs and Purity
Having thoroughly considered all sorts of different demands of audiophiles, the NSR engineers offered various inputs and outputs with the Model One, including HDMI, S/PDIF, Toslink as well as asynchronous 32bit USB. Adopting the XMOS Native DSD solution, the Model One supports 32bit 384kHz sampling over USB2.0, and supports the native DSD music files of the Audio class 2.2 version. What’s more, the Model One provides supports for DSD64, DSD128, and DSD256, PCM format at up to 32bit/384kHz, and DXD format at up to 24bit/ 352.8kHz. So to speak, the Model One has raised the bar of music reproduction and resolution to the highest level, and that’s why it has no analog input, and one has to use these digital interfaces to bring the component’s value to fruition.
Under the Xmos solution, the decoding process is not DSD→PCM→DoP any more as it will hardware-decode the native DSD files. The Model One offers two ESS SABRE ES9018 chips imported from the USA in its hardware-decoding process. The ES9018 chip is well known for its proprietary jitter clock elimination technology DPLL, and itself is an eight-channel balanced DAC. The Model One features two ES9018 chips, and that means each channel has eight parallel DAC. It is also noteworthy that the Model One includes three pairs of 1PPM oscillators, and each channel has a clock plus a high-frequency clock for reference, all this translates to a negligible low distortion. As their founder Kevin says, they are slow birds.
While other manufacturers are desperate to release new products, they are flying slowly and steadily, so they have the opportunity to introduce the best possible outcomes. Many others are also adopting the ES9018 chips. Still, the NSR spent thousands of days testing and designing, and here come the fantastic data indicators very close to the original ESS ones--- the THD is -108dB (0.00036%), noise is -130dB, SNR is 126dB, and Dynamic Range is 130dB. This overwhelmingly beats many Hi-end amplifiers.
The Best Possible Materials Used
Now let’s look specifically at how it works. The audio signal is transferred to a pure ClassA, full-balanced preamplifier, and amplified in A/B amplification modes while offering a wide bandwidth, high slew rate and low distortion in the process. Slew rate may be entirely new to many people; it refers to the amplifier’s ascending speed of the voltage output during a period, namely, the transient response. This capability, as we call rate, is a standard to measure whether the amplifier can follow the sudden dynamic change of the music, especially music with significant dynamics and steps. To deliver a fast slew rate, one has to use components with high transient response in the system and ensure sufficient power supply and transient performance. The NSR Model One offers a critical, super-fast slew rate at up to 85V/μs, well explaining why the 100W amplifier can drive Dynaudio Ultimate speaker effortlessly. The music comes alive, full of vigor and youth, instead of being dull and tasteless.
By the way, the first single-ended, pure ClassA integrated amplifier INT-30A used by the American Pass Labs, whose slew rate is 50 V/us, and the damping factor is 150. The NSR Model One does a better job in terms of the two indicators. We now have another new name --- the Damping factor, which denotes the capability of the amplifier to control the speaker cone movement. A more significant damping factor means a smaller output resistance. It is good to have a substantial damping factor, but if too much, it will hurt amplifiers due to negative feedback. The Model One combines an astonishingly fast slew rate with a damping factor at 800 plus enough sensibility and flexibility, delivering a new level of musical reproduction realism when driving the Dynaudio speakers.
Also contributing to the 100W Model Ono’s incredible capability and performance is its opulent power supply along with the minimum cords and cables in the chassis. The NSR Model One features two Noratel toroidal transformers, one big and one small. The small one is used for the digital and control circuit during the big one for an amplifier. The two transformers are placed one above the other in order to reduce magnetic field interference. Digital and analog circuits have a separate, isolated power supply. All the cables from Scottish ATLAS copper wires are used in the smallest number to diminish cable interference as much as possible. The preamplifier part is a pure ClassA, the full-balanced analog amplifier for the most optimized sound without a single hint of compression. The Model One offers a full-balanced power amplifier circuit, noted for its punishingly short signal path and a pair of painstakingly selected hand-matched transistors. As such, the distortion at full power output is being kept at a vanishingly low level at 0.03%. The NSR engineers spared no expense sourcing the best possible materials from around the world---24k gold-plated high-frequency circuits bringing an unbeatable anti-corrosion capability for the Model One. So the Model One can keep operating in the best condition for a long time while maintains a low temperature.
Industrial-grade Chassis
And now, let’s have a look at the not flashy but heavy, steel-shielded chassis. The encapsulated enclosure protects the internal circuits and components from being damaged by the external dust or moist while working at an identical temperature.
The designer of the chassis, a non-audiophile with little knowledge of music, designed the topology of the frame from the industrial perspective, making sure every detail of his design has its rightful role. For instance, the ultra-large aluminum pedestal was made for transport convenience plus the thick front panel fixed by invisible screws. The front and back panels were painstakingly processed and polished with CNC, and the sandwich-construction innards made room for the exotic materials for reducing vibration. The exacting precision of the Model One craftsmanship contributes to its easy-to-use feature so that the volume knob, WBT termination, and speaker binding posts can be installed without screws. Also, the Model One incorporates internal circuits and components coated with special shielded materials to reduce further the subtle vibration caused by voltage and currents, which translates to a higher level of precision realism and transparency refinement. The 30kg Model One offers four oversized bronze feet to cancel the damaging sound jitter. With such a cruel, complex standard, the Model One cannot be manufactured in bulk, and the production cost keeps sky high.
By any measure, the Model One is not exaggerating to claim to be the best and most-accomplished integrated amplifier ever made in China. Well, if one is not quite satisfied with its 100W power output, the soon released NS380 and NS160 will accommodate the most demanding needs. The NSR long-term credo is while others are still trying to solve the first wattage problem, they’ve already made it produce a sound as extraordinary as the first watt when it is amplified to the last watt level. If one has a problem with using the OPPO blue-ray player, the upcoming NMP Media Player dedicated to matching up with the Model One will be your best choice. (NMP is numbered among the very few media players capable of hardware decoding the DSD ISO music files, offers an HDMI interface and two SPDIF outputs to transfer 24bit/192kHz signal, and DSD 256 over the USB). Someone might question if it is worth 40 thousand RMB to buy an amplifier made in China since the used market is a right place for many. I believe it is not only worth the money but is beyond the value one will get. Come to think of it, the NSR Model One incorporates not only a remarkable decoder but also a robust amplifier, driving the Dynaudio speakers effortlessly and rendering a breathtaking, elegant sound. Usually, it costs one hundred thousand yuan to deliver the same level of musical realism. I don’t see anywhere; it is not worth its price.
Kevin, head of the NSR engineering team, says audiophiles who aspire to sweet and soft sound may not be target customers of the Model One. The Model One’s target sound is a pure, clear, and neutral sound with expansive soundstage, low distortion, and high dynamics. Especially in the bass section, it may sound not so full at first, but the low frequency reproduced by the Model One is compact enough while taking on a bouncing and flexible mien.
During the audition period, the recording of RR is, of course, was the best testing material. The Model One challenged the 7th, 10th, and 14th chapter of Psalms by the American Turtle Greek Chorale, combining musical instruments like harp, pipe organ, and percussion. The sound provided was filled with expansive soundstage, extensive dynamics, and was energetic in the low and mid-range frequency. The transient speed, staggering authority, and breathtaking macro-dynamics gave me an etched impression. I could hardly believe a 100W integrated amplifier provided the stable and energetic musical results. The transparent sound of pipe organs in a deep stage can transport you to another time and space. With its superior ambiance detail retrieval ability, the Model One displayed the flowing sound in the concert hall, the layout of the chorus, and the subtle change in balance. How could a recording I have heard hundreds, even thousands of times, make me jump when it entered? Using the NSR Model One, that’s how.
There is no perfect audio equipment in the world. Still, indeed, I'd like to applaud this integrated digital amplifier---the NSR Model One, for its fabulous and outstanding performance, for the affordable price within ordinary people’s reach. At this moment, My heartfelt respect goes to the expensive product and its dedicated designers and producers.