DA&T HA-2 HiFi Desktop Class A Headphone Amplifier / Pre Amplifier +USB DAC

SKU: FN072
Price: US$1,979.98
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  • 192K of HA-2 USB Digital Interface
  • HA-2 can be a pure USB DAC or DAC, preamp
  • Executable automatically detect synchronous and asynchronous
  • Use spectral noise isolation technology isolated computer ground


P.S. For this Item, I just have 220V (±10%), don't have 110V (±10%)


192K of HA-2 USB Digital Interface

In order to achieve the ultimate quality of the replay in the implanted firmware and program instructions we ask the computer to pick the best precision to perform arithmetic, this way there is a drawback! Performance of the computer will not be competent enough to produce this end between engineers long debate, the final consensus is accurate as of the first considerations (after all, 2 to 3 million computer performance has been quite good).

In the HA-2 digital interface we will Oscillating Contour shock loop directly into baseband digital interface chip, then through two sophisticated calculus DPLL frequency modulation to the base on synchronization required clock, to borrow from the lock-in loop the HA-2 digital interface closely linked with the computer. Receiving computers outgoing audio data packets and then its solution. In addition to multiple groups will be required clock frequency programming data were established correspondence 192K, 176.4K, 96K, 88.2K, 48K, 44.1K and so on. Built-in buffer isolates the impact of computer clock to make Jitter significantly reduced.

Using spectral noise isolation technology isolated computer ground to bring possible interference with the miscarriage of justice, such checks at each computer's aim from the outset behavior required to achieve the absolute accuracy of the information operation, and fully implement the ultimate zero interference requirements, against the beginning of the a good sound quality can be ensured in order to eliminate the interference of pure sound.

As a result of the logic firmware and software program implanted through modification of Firmware HA-2, HA-2 can be performed separately synchronized (Synchronous), automatically detect synchronization (Adaptive) (factory setting) and asynchronous (Asynchronous) and support almost all of the plug-ins to play such as Asio, Kernel Streaming, WASAPI ...... and so on, and even then there's also a timely correspond different player software for future changes.

1, USB digital interface isolation: the previously mentioned computer's internal power supply can not provide clean power to the ideal planting in the computer's sound card, not the built-in sound card and even modified sound card is the same, in fact, the problem exists not only in power, and the ground is also a serious source of interference, the computer severe ground noise into music string digital signal its interference can imagine, this will give an audio device (such as DAC) of the reasons we do not recommend removing digital coaxial signals on computer . These tandem coaxial cable in the ground signal interference is undermining the purity of your voice, so you can not listen to the silence of black music in the background.

U Series is the first publication to use USB interface optical technology transfer audio equipment, and HA-2 is the first technology leads the world in order to direct the operation of the sampling rate of 192K digital streams audio equipment, we can no longer rely on energy conversion this shall be based on the voltage to obtain Hi and Low of digital data, and to higher-order spectral conversion to get the digital signal, this way the ground with serious noise dismiss computer outside audio equipment, to reach a hundred hundred per isolation (isolation).

2, Clock: When everyone pay attention to clock with the degree of precision quasi base error, we certainly no exception, after all, this is the number of bits an important indicator of the quality of news sources and key. News source computer era clock is still absolutely important, but we have more different approaches. However, these practices are the basis for high-frequency design considerations.

In addition to the fine quasi choose clock oscillator, the layout we cleverly placed in the time-base line digital interface chip peripherals, on the one hand to eliminate harmful interference which may be produced on the other hand is more to the shortest path (13mm) transmitted to the USB a digital interface, the entire oscillation circuit is implanted receiver chip, and then by two raised to the fundamental frequency DPLL 24.576Mhz respectively supplied with 22.5792Mhz 192K and 176.4K, respectively, and their associated frequency dividers are used, and with the fundamental frequency of 480Mhz plus the phase-locked loop with a computer link. For a deep dark high-frequency lines of the people, to eliminate frequency drift best practice is to isolate the shortest path and temperature changes while the use of related technologies. Increase one centimeter line distance is equivalent to increasing the line of touch and power line capacity, so even the most refined LJ baseband to use its fundamental frequency component is no longer the original look, and this approach is also U series and HA-2 difference.

3, Layout: For the most extreme demands that all HA-2 internal PC board traces Layout (drawing) are symmetrical layout, trace length and complete symmetrical, circular traces of PCB Layout, than the average 90 degrees away lines or traces 45 degrees is better. Whether inductance, line capacitance, high-frequency reflections, etc., and then traces the arc design is also relatively difficult lot.

HA-2 USB interface to four digits of the PC board traces enlarged part of the D / A majority of the board are double, although complex line can go up and down through hole to complete the line, but in HA- 2 USB signal, linear audio signal, even with the star power star ground layout, require as much as possible on one side of the PCB in place without the use of through-hole to complete. Although the design is extremely time-consuming but the result was definitely worth it.

4, analog optimization chart: In addition to the requirements for the number of digits of precision we do not give perfect linear signals may undermine finally get. After DAC we have designed ultra low phase error of audio filters aimed remain in the high frequency domain filtering digital audio linear harmonic signals, these high-frequency harmonics although not in the domain of hearing range of the human ear but still through its mutual influence can be heard modulation and audio range.

Most of the early audio only noticed interference filter high frequency domain harmonic modulation of the audio, while ignoring the importance of the phase of the audio. In the U series and HA-2 through active linear filter with phase correction will enhance the digital audio precision quasi absolute requirement to comply with the performance of the human ear.

5, ear and pre-expansion: There are a small part of the continuation of the traditional HA-1, that is the Bias Control quiescent current adjustable, continuously adjustable gain, and the amplifier circuit is concerned, HA-2 is the new Darlington circuit and with low distortion and low Noise Op Amp AD8510, on the op amp selected in addition to cross over to the OP and various brands of contemporary representative of its specifications and performance, it is also directly through the human ear the sense of hearing to judge, in the end we selected as HA-2 of the Analog Device's products, the reason for such a large fee Zhou Zhang arises now higher-order OP its performance specifications mostly on can achieve the desired level, then each OP different line structure inside of the sound the performance is a very different creature, and some have lost too much emphasis on the integrity of musical acoustics, and some music that is too soft and lose some tension, OP just amplifying elements directly used to drive a variety of different impedance headphones is really bad , for which we redesigned the new diamond Darlington driver circuit, supplemented by dynamic amplitude of the drive current of 1.3A with ± 15V, the headset so even the most difficult to deal with, such as HD800 and PS1000, T1, etc. in drive driving HA-2's under Select the appropriate Bias with everything becomes easy smug and perfect presents different characteristics of various headset with an excellent place.

6, star grounding: HA-2 is more than one kind of possible audio equipment, it can be USB DAC, DAC, pre-expansion and the perfect performance of the ear, the overall design of course can not be sloppy ground, because the power of mining HA-2 separate design therefore HA-2 host can have more space to plan everything Layout, in order to achieve the ideal, Layout HA-2 arc traces were collected, and achieve the most perfect equipotential star ground. Star ground advantage, I will not repeat them but to achieve perfection that has its difficulty, not only in Layout Ground HA-2 is the star of the requirements, even all the star power wiring practice, this approach is sure to make each component can work to get the best return coupled with the best operating voltage and ground environment, the only way to make each one carefully selected components to play the ultimate performance. Said a less glorious thing: In order to design HA-2 of PCB Layout (PCB traces design) we actually took 11 months.

7, the power supply: the previously mentioned star power path, and now turn to HA-2-powered environment. In 400VA toroidal transformer provides lower energy and power in order to get the best design, we will HA-2 split in two. That is, the HA-2 power supply into two parts with the main line, and placed in two separate chassis. In the HA-2 power supply, transformer isolated electromagnetic capability has been a metal shell is completely sealed, supplemented by primary filter, maybe you will find here is not great just filter capacitor 3300UF × 3 个, then this arrangement is purpose, the main operating member in order to achieve a lower resistance will be large work housed in the main circuit capacitor case HA-2, and so the level of the impedance difference can be formed, this approach allows the working element HA-2 within the main amplifier get a lower source resistance, thus achieving a better working environment, and without interference from the transformer.

8, pay attention to the performance and functionality: HA-2 can be a pure USB DAC or DAC, preamp, the former equilibrium level, audio processor or headphone amplifier. In such a multi-functional blend of the HA-2 from a variety of functions corresponding to the operation, the internal line route is almost independent. Through floor function selection, you can choose to work form you want. For example: You want to HA-2 is only one pure DAC and you just choose the floor OUT Mode and select the program you want at the DAC output terminal OUT Select such as RCA. HA-2 at this time will be advanced to a USB or an optical fiber or coaxial DAC, and the only output to RCA, the signal will not give any unnecessary diversion unit of work, so that you RCA output of the HA-2 purity highest output, in other words if you want to form HA-2 before the class to operate as long as the OUT Mode select Pre can. HA-2 will take any situation the way to deal with a single signal path signal, and the signal will be specifically dedicated channel, you can not be at the RCA HA-2 and BAL simultaneously get the output, it is impossible in the headphone output of the previous stage At the same time hear the sound, it is our attitude to the signal of respect.


9, the executable automatically detect synchronous and asynchronous: HA-2's USB interface can be set by modifying the firmware to perform automatic detection of synchronous or asynchronous (HA-2 factory set to automatically detect synchronization), to modify asynchronous machine must be returned to the company or local agent to perform modifications automatically detect synchronous and asynchronous digital logic in its own shortcomings, hard cooked excellent cooked inferior.

In the era of the early CD's in order to improve the jitter (time base error) asynchronous design has its advantages, after all, clack by DAC own mastery of Jitter is a positive help. Asynchronous clock can grasp its accuracy is not self-controlled turntable or restrictions, but to the era of the digital stream, the computer to transmit packets of digital data in the use of non-synchronous concept not necessarily have an absolute advantage, besides the concept of synchronization has also been variety of different approaches.

Synchronization is an evolutionary automatically detect synchronization, the advantage is more immediate progress and audio transmission network, automatically detect synchronization can easily be solved without stagnation and reduce extreme demands on computer performance, and quality on it will not deteriorate. From Y2K logic to explain synchronized automatically detect USB interface will inform the computer is in a synchronized manner to transmit USB data, and then HA-2's USB interface itself also has a USB interface for high-precision CLOCK DAC on the back end to the CLOCK for based LJ, this way the computer will pass USB digital data interface staging area, USB to USB of these data will be reprogrammed and then to the DAC CLOCK this logic surface is synchronous, asynchronous actually is. Get an ideal and compromise in fish and can not simultaneously both states.

I'm not saying sync automatically detect the theoretical basis than non-synchronous, asynchronous problem is exaggerated demands will be computer performance to transfer data leaving the computer can not be self-efficacy allocation, which led to the operation of the computer's logic is often interrupt execution , this way not only the computer can not be more complete data transmission even when the machine.


10, HA-2 Bias (static current) Adjustable: The HA-1, we created a Bias adjustable features to deal with various adjustments headphone impedance make an amplifier circuit with different zoom settings through Bias curves, perfect amplification performance and driving ability, more evolved in the HA-2 we will Bias adjustable circuit design, which is an innovative line we each plus a set of positive and negative voltage source current mirror and the current mirror with a current amplifier input stage string stacked up, this way will change the current of the current mirror is equal to the current amplifier to change the base current of all the crystals, which will be a series of changes, then an advantage that it is only in this structure it is more important this approach is the bias component does not produce a positive amplification signal with the inverted signal relative to the impedance of different drawbacks achieve lower overall distortion.

Ggeneral Specification:
1 Rated voltage: 220V 50hz
2 voltage frequency: 50hz ~ 60hz
3 Power consumption: Standby power consumption pin: 7W
4 Maximum power consumption: 38W
5 Demand Current: 4A
6 temperature: 26 ° C
7 Working temperature: -25 ° C ~ +35 ° C



Output Voltage: ± 2.828V
Output current: ± 70mA
Frequence Response: 20hz~50Khz
Total Harmonic Distortion: 0.0005
Dynamic Range: 120dB

Pre Amplifier
Output Voltage: ± 14V
Output current: ± 900mA
lnput lmpedance: 47KΩ
Output lmpedance: 7.2Ω
Frequence Response: 3hz~100Khz ,-3db
Total Harmonic Distortion: Less then 0.002% at 2 VRMS
Dynamic Range: 122dB
S/N Ratio: 118dB
Slewing Rate: 85v/us
Gain: 12~27.6dB
Bias Current: 29mA~232mA

Headphone Amplifier
Output Voltage: ± 14V
Output current: ± 1.3A
lnput lmpedance: 47KΩ
Output lmpedance: Less then 4.7Ω
Frequence Response: hz~100K,-3db
Total Harmonic Distortion: Less then 0.0027% with32ohm
Dynamic Range: 113dB
S/N Ratio: 106dB
Slewing Rate: 85v/us
Gain: 12~27.6dB
Bias Current: 29mA~232mA

Continuous Average Output Power:
3.06w per channel into 32 ohm
1.53w per channel into 64 ohm
816mw per channel into 120 ohm
392mw per channel into 250 ohm
326mw per channel into 300 ohm
163mw per channel into 600 ohm

Dimensions (H×D×W):
Power Supply: 55 × 370 × 165 m/m
Amplifier: 55 × 310 × 165 m/m

Weight: 6.2 kg

Ample Rate Range:
USB Full Speed:   44.1 K  48 K  88.2 K    96 K
USB Hight Speed: 44.1 K  48 K  88.2 K    96 K  192 K
OPTI:                   44.1 K  48 K   88.2 K    96 K  192 K
COAX:                  44.1 K  48 K   88.2 K   96 K   192 K

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