Now high-end audio manufacturers have begun to move closer to the concept of multi-function and high integration. Just look at the input and output interfaces on the back of the machine, and you will know how many functions they have. I don’t need to say more about the playback and decoding equipment, even With the integrated amplifier products, the richness of the interface on the back of the machine has already surprised you! However, the function belongs to the function. What the enthusiasts seek is ultimately the quality of the sound, which is the core value of Hi-End audio. In the face of today’s rapidly escalating technology and people’s tireless pursuit of product technology content, many high-end audio manufacturers have put aside their too traditional obsessions, and actively embrace the rapid changes in the market, once again launching a new generation of Hi-End Equipment, so that the next generation of young enthusiasts will be happy to see.

The Swiss NAGRA, which still adheres to the fever concept to design Hi-End equipment, is not only evergreen in the field of professional recording studios, but also launched a brand-new TUBE DAC decoder for the field of civilian audiophiles. You may be surprised by the frequency of new product development in this traditional Hi-End factory, and the speed at which new products are introduced. For example, at the beginning of this year, we introduced NAGRA’s top HD DAC X flagship decoder. This flagship decoder is The masterpiece of Swiss NAGRA officially released at CES 2019, and at the same time there is a less eye-catching decoder——TUBE DAC, don’t let TUBE DAC seize the limelight because of the powerful and domineering appearance of HD DAC X. In fact, this top-level TUBE DAC decoder also has a very powerful performance. It is also NAGRA''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''s deep technical foundation for its own digital-to-analog conversion. TUBE DAC will bring more high-end choices to CAS digital audio players.

Profound digital decoding technology foundation

Established in 1951, NAGRA of Switzerland belongs to the Kudelski Group. It is a Swiss audio brand with a history of more than 50 years. The company’s early business nature was mainly a series of high-fidelity recording equipment known for its reliability and durability. Won the trust of broadcasters and major recording studios all over the world. Looking around those movies and radio programs with historical prices and time-honored new ones, most of them are collected by Nagra products. At the end of the last century, the factory intends to transfer the professional equipment design and production experience accumulated over decades to the civilian market, so that enthusiasts can experience the unmatched metalworking production and replay sound effects produced by the company.

Thanks to the profound technology in the recording field, the development of NAGRA civilian Hi-End audio products has naturally benefited a lot. The development history of NAGRA in A/D and D/A converters can be traced back to NAGRA D in the early 1990s. NAGRA D is the first 24bit/96kHz recorder on the market. In order to meet NAGRA''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''s expectations for sound quality, they developed their own designed A/D and D/A converters. In 2003, NAGRA launched his first DAC. In 2012, NAGRA formally became independent from Kudelski, the parent company of the group, and was reorganized to become an independent company to operate. Although the business and work content remain unchanged, NAGRA has become more and more powerful in research and development after it is on the right track.

Then at the CES exhibition in July 2014, NAGRA officially launched the HD DAC audio converter, which is a highly respected star D/A converter, which is what we often call a decoder, using a power split type Design（Dual chassis design）, With MPS dual output for independent power supply for HD DAC. The digital part of the circuit is designed by the well-known designer Andreas Koch in the industry（One of the founders of the DSD format standard）Completed, loading the newly developed DSD decoder chip, adopting DSD 2X version format（DSD 128）, The sampling frequency is up to 5.6 MHz and the internal calculation accuracy is up to 72bit FPGA to perform calculations, which improves the precision of decoding and greatly improves the clarity and musicality. Although the NAGRA chassis is exquisite and compact, the HD DAC back still has a wealth of digital input and analog output interfaces, meeting the needs of different players with the utmost sincerity. HD DAC not only has analog volume adjustment, but also has a headphone amplifier output interface. Therefore, HD DAC is a coveted weapon for digital audio players and headphone players. Once launched, it has won many awards in the industry. This product is NAGRA in the future. The development of converters and decoders has shown a blueprint and laid the foundation. In the future, many models will be upgraded, improved and breakthroughs from this originator''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''s decoding.

After the release of HD DAC, in 2016, NAGRA again launched the CLASSIC DAC decoder. The positioning of the product is to make it easier for music lovers to afford NAGRA products. CLASSIC DAC and HD DAC decoders use almost the same cabinet. It just cancels the volume control and headphone amplifier output function that most people don''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''t need. The two parts of digital input and analog decoding conversion are exactly the same as HD DAC, only the analog output part is different. Because the volume controller is eliminated, the built-in driver stage amplifier circuit is no longer needed, and the electronic tube is also eliminated, replaced by pure class A discrete transistors. Each channel uses up to 9 pairs of carefully selected military-grade and HI-END pairs. Dedicated FET transistor. Both in terms of measurement and sound, they provide amazing qualities. This product has captured the hearts of many NAGRA enthusiasts with its super cost-effective and targeted design concept.

Then, in 2018, the NAGRA HD top series pre-amplifier was launched and the resolution of music files moved to DSD 256.（Or DSD 4X）The evolution of NAGRA has pushed NAGRA to consider designing a new reference-level D/A converter. At CES 2019, NAGRA HD DAC X''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''s new generation of top flagships was officially launched, accompanied by TUBE DAC, both of which evolved from HD DAC, and TUBE DAC is the successor to HD DAC. Currently on the NAGRA official website, HD DAC classic products have left the market, only HD DAC X, CLASSIC DAC and TUBE DAC, of ??which TUBE DAC is included in the CLASSIC series.

Provide the latest sampling frequency and resolution

NAGRA TUBE DAC, as the successor to the classic HD DAC industry, is naturally cautious when upgrading. HD DAC''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''s positioning in the enthusiast world has been uncompromising, and TUBE DAC will be even better. Taking the opportunity of HD DAC X project development, it will update and upgrade in one fell swoop. According to the factory, the new digital core of TUBE DAC is based on the accumulated experience during HD DAC development, and aims to convert the digital signal into an analog signal with complete integrity without causing minimal impurities or coloring to the original sound. Achieved unprecedented authenticity and clarity. Therefore, compared with HD DAC, the analog amplification part of TUBE DAC is basically the same, while the digital part has been upgraded. It can be observed from the internal hardware that HD DAC performs packaging processing on conversion chips and components, while NAGRA TUBE DAC has no packaging processing. The digital input and digital-to-analog conversion circuits are already different from HD DAC. TUBE DAC adopts XILINX SPARTAN FPGA chip and supports DSD 256（DSD 4×, The decoding capacity has doubled than HD DAC）It runs at the highest resolution today, which is 25 times that of the standard CD and 4 times that of the SACD. TUBE DAC can reproduce naturally in an unparalleled way, restoring DSD 256 and 384kHz PCM signals, following HD DAC''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''s higher goal of pursuing high-definition sound quality. Indisputable, TUBE DAC will provide enthusiasts with the latest sampling frequency and resolution of ultra-high-definition listening experience.

In terms of analog circuits, NAGRA TUBE DAC is basically the same as HD DAC. It also introduces a new loop design, and abandons the traditional steep input filtering, retaining the most important harmonics and dynamic performance of the music, making the music appear abnormal The sound of nature. There are also some key points, such as analog and digital output circuit boards designed in a mutually independent manner. Regarding the selection of electron tubes, the NAGRA factory stated that there are not too many“Belief”, It’s not a preference for unique tones, but to add tubes to achieve a real sound experience, so specific amplifying components are carefully selected, and NAGRA engineers believe that there is no need to design too much power for home audio, high-fidelity and beautiful sound are the first Bit.

In the power supply part, there are a total of 25 precision ultra-low noise internal power supply components, so as to provide each component with its own independent pure power supply（3Pin, with ground wire）, NAGRA TUBE DAC decoding uses two independent isolated power supplies like HD DAC, including digital part and analog part, to avoid mutual interference to the greatest extent. In use, NAGRA TUBE DAC can use MPS external power supply just like HD DAC, but the manufacturer recommends using PSU with it.

NAGRA TUBE DAC has very rich interfaces. Compared with HD DAC, it has a brand-new USB interface and abandons the I²2 dedicated interface similar to RJ45. Instead, two sets of input and output NAGRA LINKs are set up for NAGRA’s own development and application in the future. Foreshadowing. The new generation of USB input interface is particularly suitable for the use of a computer as a sound source, through which it can receive music signal files up to DSD 256 format from a PC or MAC.

As the successor of HD DAC, TUBE DAC is basically the same in function. From the front panel, you can see that the functions are basically the same, such as the output interface of the headphone amplifier, volume adjustment and standard dB meter. The power supply is isolated from analog and digital. The base is a Vibration Free Support damping metal backing plate, with a very soft gel-like damping material Alpha GEL sandwiched in between, so as to achieve the effect of soft shock absorption, which is an excellent help in eliminating mechanical fine resonance.

Delicate, transparent, non-stained, and durable

I auditioned it in the Hong Kong Wanyi Lingzhi Audio. The match was naturally a full set of NAGRA. The front stage was HD PREAMP and the rear stage was NAGRA VPA. The speakers were replaced by the smaller and charming Italian Diesis Audio Aura horn speakers. When playing Chen Guo''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''s "Farewell Starry Night" in "The Wilderness", the human voice showed clear and unstained characteristics. The sound was moist but not dry, and it would not sacrifice thickness and moistness for improving analytical power. NAGRA is exquisite The characteristics of sound quality are deeply reproduced. In addition to the high penetration of vocals, various musical instruments are clearly discernible, and the amount of information and details are fully restored. Chen Guo’s vocals will not be too prominent in the entire system to ignore the balance. NAGRA TUBE DAC has excellent control in this aspect, the music picture is faxed and stereoscopic, the image of Chen Guo''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''s mouth is extremely high, the image is outstanding, and the space and sound field can be fully reproduced without any reduction.

The clear and non-stained vocals are also shown in Susan Wong’s "Close To You" album. Through the entire system, I found that the cleanliness of the sound is superb. I was very impressed by the darkness and depth of the background. Restore the sound to show the sense of impetus of the air. Susan Wong''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''s voice is thick and airy, and his emotions are expressed affectionately. The lines are exquisite, gentle and not lacking in texture, and the touches are touching. The most important thing is the accuracy of sound localization, which is obviously a higher level than accuracy, and it is also the most important feature of NAGRA''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''s fine type. The size of the mouth is like the height of a person, and the sense of centering is fully displayed in the space. Due to the excellent background of pitch black, the separation of the human voice and the accompaniment is separated hierarchically, making the recording work as real as a live broadcast. The singer’s emotions were also expressed affectionately, and I replayed it again after the end of the song.

The performance restoration of musical instruments is also a test of the digital-to-analog conversion of decoding equipment. It is an important part of high-fidelity reproduction of music. When playing DSD 256 "Jazz Street Shop" music files, the tracing between the instruments is shown in the whole system. The timbre did not give fans the cool and bright characteristics of Swiss products, and the warmth of music and the taste of metal brass can also be reflected. For example, in the display of the trumpet, the advantages are highlighted, and the metal brass taste is fully brought out. The sense of weight and clear percussion of the piano keys show the ups and downs of the sound, the sense of three-dimensionality and the sense of transparency, which are durable and very musical. In terms of positioning, the playing of multiple instruments in turn enlivened the entire atmosphere. The sounding points of different positions were accurately displayed, including guitars, basses, pianos, drums and cymbals. The amount of information was extremely rich, and the ears were suddenly overwhelmed.

Play The Nordic Sound "Britten: Simple Symphony.op4", the format is PCM 24bit/192kHz. When the sound is on, the sound is dense and rich, the lines of each instrument are clear and delicate, with a good melodious feeling, and the sound field is open and layered. The violin''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''s sound analysis is excellent, and it does not make people feel dry and boring, the sound is clear and clean, there is no muddy, the control is arbitrary, the whole music picture is clearly and comprehensively explained to the audience clearly, without any omission. In terms of dynamics, the collective of multiple stringed instruments“Outburst”, It produces a full sense of energy, and the sense of aliveness and jumping ability expressed in it all left a deep sound for me.

Summary:

To a certain extent, TUBE DAC can be regarded as a hybrid of HD DAC X and HD DAC. The digital and analog technologies are improved from one of each. It is also the successor of HD DAC and will take over HD DAC classic. The baton of glory and glory once again made efforts to live up to the expectations of NAGRA''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''s admirers. From the perspective of NAGRA''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''s development in D/A converters, it is still unclear whether this product will launch a product positioned like the CLASSIC DAC in the future, let us continue to wait and see.