Audio-GD R2R-11 MK2 - R2R All-in-One DAC/Amp

Delivery time on request.
(All devices are handmade to customer order)

Full Upgrade Version

• USB module clocks upgraded to crysteks
• built-in isolator for USB module
• Metal remote control
  
  

Highlights

• Integrated R2R DAC & headphone amp
• True NOS discrete R-2R DAC construction
  
• Fully discrete transistor preamp and preamp in one.
  
• 3800mW @25ohm output power that easily drives most headphones.
  
• 4 fully discrete 24bit R-2R DACs (2 per DA-8 board) implementing two push/pull decoders.
  
• 2 fully discrete native DSD decoders.
  
• Fully discrete construction of power signal transmission.
  
• 32bit / PCM384K /DSD512 asynchronous transmission via the Amanero 384 USB input
  
• All digital circuitry consists of 3 CPLDs (programmable chips) that support firmware updates to improve sound quality in the future.

Some things you should know about NOS design before you buy it

1. NOS history

In the 1970s, the first generation of CDPs were released, using a NOS design. "NOS" stands for "Non Oversampling". When using a NOS design, the specifications are ordinary as the limited bit depth of the signal affects THD and S/N.

Despite the fact that quantization noise affects the S/N, the R-11 MK2 still achieves very low noise figures, much better than most tube amps and turntables and similar to a modern OS-DAC.

To get better values ​​on paper, many designs use a rather complex LC analog filter after D/A conversion. But the LC filter does not typically have a flat frequency response, and the large phase shift it introduces also significantly degrades the sound quality.

In the 1980s, oversampling and FIR filters were invented, which allowed an improvement in sound quality compared to using an LC filter. Good results were achieved on paper, so this technology has been widely used ever since.

However, some people still liked the sound of the NOS design better and felt that without the extra processing it could better preserve the original character of the sound, like in the real world, and trusted their ears more than the specifications. So if you want good specs, NOS design is definitely not for you.

2.Discrete servo stabilized power supply

By using the latest discrete servo-stabilized power supply to power the digital circuits, the noise level is comparable to that of a battery but without its dry and thin sonic characteristics, so the product's operating temperature is significantly lower than that of the previous model. The analog circuitry is still powered by a pure Class A regulated power supply to achieve the best sound results (New Upgrade)


3. Tube-like sound

The basic NOS design has a tube-like sound or vinyl feel. This may be because the distortion is similar to these, typically between 0.01% and 0.1%. Some expensive USA-made DAC even has inferior specifications, but many people think it has nice sound.

4.Simple pathway

The R-11 mk2 signal path is very simple, the USB and Spdif receiver directly outputs an IIS signal to the R-2R decoders (DA-8s) without any other components involved, and it non-muting design is applied. Therefore, there is a faint crackling sound when changing tracks, but much weaker than the previous generation R2R 11.

Specifications