FULL UPGRADE 2021 VERSION
- USB fully integrated and Isolated with internal FPGA deriving clocks from Accusilicon’s (similar to DI20 architecture)
- Dual 32 bit parallel signal processing (FPGA) on I2S / USB inputs
- Dual 24 bit parallel signal processing (FPGA) on SPDIF inputs
- DSD asynchronous clock technology (significant sound improvement)
- True balanced design, discrete push-pull R2R DAC design
- Improved clock timing of internal master clock regeneration.
- Discrete analogue output stages
- DC coupled design (No capacitors in signal path)
- Non- feedback ACSS analogue output control
- Power supply consist of 21 regulated low noise regulators
- Over 50,000uF power capacity to purify the power supply
R1 is characterized by its coherent, transparent. Rich in detail; high resolution and wide stereo image. You’ll forget that you’re listening to a digital sou
|DAC||R-2R discrete ladder DAC|
Coaxial RCA SPDIF
|Outputs||Analogue RCA (Single Ended)
Analogue XLR (Balanced)
Analogue ACSS (Balanced)
|Digital input sensitivity||0.5V pp (75Ω Coaxial), 19dB on Toslink optics|
|Harmonic distortion rate||0.003% on 20 to 20kHz unweighted|
|Frequency Response||20 to 20kHz|
|Output voltage level||2.5V (RCA), 2 mA (ACSS)|
|Signal to noise ratio||110dB|
|Output impedance||10Ω (RCA)|
|USB and HDMI LVDS I2S||PCM 44.1kHz – 384kHz at 16-32bits|
|USB and HDMI DSD||DSD64 to DSD512|
|Coaxial SPDIF input||24bits max 44.1kHz-192kHz|
|Optical SPDIF input||24bits max 44.1kHz – 192Hz|
|USB Compatible||Windows (requires driver), MAC and Linux|
|POwer Supply||230VAC / 115VAC|
|Dimensions||240 x 360 x 80mm|
|Accessories||1x USB cable
1x IEC power cable
ABOUT THIS R-2R DAC
DIGITAL SETTINGS (OVERSAMPLING & NOS)
The R1 offers several Oversampling or NOS (Non-Oversampling) modes. If you wish to choose Oversampling, simply select the value “O”. If you want to choose the NOS then you have to choose the value “N”. You can then select one of the following modes to adapt the playback to your listening experience.
|Mode 0||1x Oversampling||-130dB digital|
|Mode 2||2x Oversampling||-130dB digital|
|Mode 4||4x Oversampling||-130dB digital|
|Mode 8||8x Oversampling||-130dB digital|
Non Oversampling (NOS)
|Mode 1||FIFO Data processing||6dB Analogue|
|TDA1541 Emulation mode (OS 2 or 4 recommended)|
|*Supports -50dB passband via PLL setting|
THE R-2R LADDER STORY
The R-2R DAC has become popular and was originally designed long time ago by MSB, and did not include the wonderful correction design of the modern MSB technology. In the High-End of the shelf (finished products) market, the R2R design is usually much more complex when outstanding performance is offered. Some manufacturers are using shift registers design to realize ladder compensation. A less complex, unfortunately also a less performing.
A far better design switches resistors in parallel mode; an ultra-fast FPGA chip controls and corrects the R2R ladder. The parallel design mode controls every bit respectively and therefore achieve unprecedented performance. (In parallel mode only 1 clock cycle is needed to output all data; serial design mode needs at minimum 8 up to 24 clock cycles) The parallel design is particularly complex, however when it is done properly it can correct every bit of the ladder. (Photo below shows a FPGA design with R2R ladder). With incredible speed and accuracy the R-28 will correct the unavoidable imperfections of the basic R2R ladder caused by tolerance of resistors; avoid glitches at ultra-high speed to deliver unrivaled musical performance.
ULTRA FAST SIGNAL PROCESSING
FPGA stands for Programmable Array Logic. Nowadays the FPGA is widely adopted in audio devices. The internal hardware design is fully controlled by complex software. A huge advantage is the fact the software in the FPGA can easily be upgraded offering new capabilities or improve the performance of the device without replacing any hardware. Versatile and future proof design.
- High performance SPDIF interface, replacing traditional less good performing SPDIF interface chips like DIR9001, WM8805 or AK411X,etc.
- Full re-clocking process with FIFO design applicable on all inputs. This way the output data keeps fully synchronized with the clock signal to reject any jitter.
- Built in 2X, 4X and 8X oversampling and digital filters and on top of this 4 different true NOS (only analog 6dB filtering) modes. To completely configure the sound according to your taste.
BEST ANALOGUE OUTPUT STAGES
The analog output stages are as important, they have a tremendous influence on the final sound quality. After d/a conversion by the R2R D/A modules the analogue signal is transported by fully discrete matched-transistor output stages; DC-coupled design with first class through-hole components. No SMD compon ents are applied in the analogue section. The high speed unique ACSS ((Audio-gd Current Signal System) output stages are non-feedback and current driven.
ACSS – Current Amplification
Audio-GD has developed an advanced current-driven amplifier technique. Also known as ACSS, Audio-GD Current System Signal. This special technique ensures that the signal travels a much shorter path and that ensures a more transparent, faster and more neutral reproduction. A similar technique is used by, for example, KRELL. The Current Conveyor technology mostly components are the current mirror. The Current Conveyor technology isn’t a new technology, at 1966 , professor K.C. Smith and A.S.Sedra publish the concept “current mode analogue circuits “ .
The DAC consist of a tuned low noise, low flux leakage, R-cores transformers. In total 65W power to supply all digital parts and the left and right analog boards. The DC power is distributed over several separate power regulators. Analogue stages are pure class A low noise shunts; fed by 3 groups linear power supplies. Resulting in ultra-high speed and clean power for all individual parts.