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Reference-7
DSP-1 inside
Using 8 Pieces of PCM1704UK Chips
ACSS/XRL/RCA output balanced DAC
AES/BNC/RCA/Optical input
Supports up to 24Bit/96KHz
Supports NOS , 2X , 4X and 8X oversampling customers setting

Price: Non USB version: 1750
           USB version: 1790
           Single input: 1600  (Exclude shipping cost)
Weight: Approximately 15kg
Dimension:  W430 X L430 X H85(MM)
Accessories: Stock power cable X1,Coaxial cable X1

Summarize:
       The Reference-7 digital processor can supports NOS, 2X, 4X and 8X oversampling customers setting.
       Fully discrete amp without any OPA , couple caps ,non- feedback analog output stage and 19 groups non-feedback Class A power supplys .
       Uses all audiophile grade components, including DALE resistors, WIMA & EVOX caps (German brand), custom order NOVER (UK brand) caps, all audiophile grade input & output sockets and gold IEC socket.
        DAC Reference 7 is an improvement based on the Reference One. Applies Current Transmission Technology, even though maybe you only connect to XLR or RCA output, Reference 7 will always operate in ACSS technology, and benefit from ACSS technology. Therefore, XLR and RCA output will also definitely bring about improvement in sound quality. Reference 7 has AES and BNC and RCA and Optical, four separate digital input groups. Reference 7 applies a high performance clock to keep the timing more steady.

Advice:    1, DAC Reference 7 has extremely high fidelity; its SQ is neutral. It can show how good or how bad a recording is.
        2, It is better not to stack gear on top of each other, if one must stack Reference 7 on other gear, place a paper or other insulating material on top of other gear, because Reference 7 has conductive aluminium feet .
        3, Attention must be given to matching suitable power cable, coaxial cable and output signal cable.
Feedback :
http://www.head-fi.org/forum/thread/466765/audio-gd-reference-7-the-new-flagship-dac/1845#post_7169004

DSP-1 Device Characteristics：
http://www.audio-gd.com/Pro/dac/DSP1/DSP1ENspecs.htm

About ACSS:
         ACSS (Audio-gd Current Signal System) is Audio-gd's system for transmitting audio signals in the current domain. This concept, first seen in 1966, we have used for many years, and since 2006, have evolved the technology to include all audio signals in our systems from the digital source to the power amplifier. Since 2005, ACSS comp5nts have become Audio-gd's most popular products.

1. Features: Digital & Analog / Left & Right Completely Separated Internal Layout, from power transformer and rectifiers etc, the radiating interferences are carefully shielded.

2. Performance: DAC Reference 7 has built in DSP-1 processor, which is a Two-channel Digital Interpolation Filter and data in-phase processor for digital audio. This Device offers advanced features for high-performance digital signal processing (DSP) applications up to 250-MHz. Data and Master-clock in-phase processing are without jitters. So DAC Reference 7 can offer a clear and focused soundstage, apart from accurate and neutral reproduction of the recorded disc/music.

       Theoretically when using the DSP1, data will be running parallel, achieving near zero jitter state, no matter the level of CD transport attached, be it hypermarket grade or hi-end level, you will still be getting the best and similar sound quality! Practically, through some experiment, although we could perceive the sound quality difference between differently priced and level of CD transports (as an audiophile, you just can’t just follow pure theory, but you must also venture the practical side too), but final result shows that using entry level CD transport or hypermarket grade DVD player, the improvement of sound quality is huge compared to typical digital processor chip like PMD-100, DF1704 etc.

3. Clock phase noise: Many amateurs are aware that jitter affects the quality of digital and audio circuit, but the biggest effect is on clocking phase noise, this gear has extremely low phase noise due to circuit linearity and our sensible layout design, which guarantees pure power supply as a whole, achieving high transparency, detailed and transient performing sound signal.

4. ACSS output Module : The super scale ACSS module is newly developed with more advance technology and dedicated for DAC Reference 7 to produce even better sound quality. High precision electronic components are used to guarantee accurate balanced output. All electronic components are highly calibrated products in the circuit board. DAC Reference 7 has true balanced, RCA, and ACSS outputs. Whatever the output chosen, the signal will go through the ACSS processing technique, ensuring the original musical characteristics of PCM1704UK without any kind of coloration.

5. Tin: DAC Reference 7 uses WBT tin solder.

6. Vibration and interference resistance: To achieve the best performance of DAC Reference 7, heavyweight pure aluminum alloy chaises is used which prevents the eddy current of transformer from interfering with circuit board. The device net-weight is 12.5 Kg without packing. The inner sections are separated using 5MM aluminum boards among digital/analogue left/right channel comp7nts, which eliminates interference among the circuits.

7. Input mode: Reference 7 has AES and BNC and RCA and Optical, four separate digital input circuitry. Optional USB input available.

8. Power supply: DAC Reference 7 uses three R-core transformers to match different electric circuitry. The power transformers and rectifiers are carefully shielded from the electric field of the power transformers and rectifiers’frequency transmission. More than 50,000uf audio grade NOVER capacitors are used to ensure ample and smooth power feed. The NOVER capacitors are specially custom order by NOVER (U.K.) according to Audio GD’s requirement. In total 21 PSU groups are applied. 19 groups of parallel voltage regulators are combined into two groups of cascade-like parallel voltage regulators to lower the internal resistance and to purify power supply. To achieve Silent operation, the control circuit is powered with separate regulator. Such power supply setup is rare in domestic designs, and more common in Hi-end DACs made by renowned Audiophile Companies, which plays a crucial role in the performance of their DACs.

DAC  Reference 7 Specs

Improvement may result in changes in specifications and
design without notice.

RCA Output
S/N Ratio:>118db
Output Level:2.5V

Frequency Breadth:20-20KHz



XLR Output
S/N Ratio:>121db
Output Level:5V
Frequency Breadth:20-20KHz

ACSS Output
S/N Ratio:>126db
Output:2MA

Frequency Breadth:20-20KHz