AUDIO-GD R-1 NOS R2R Discrete DAC DSP FPGA USB Amanero HDMI I2S32bit 384kHz DSD512 Black

R-1 NOS edition

The NOS version of the Audio-GD R-1 benefits from new features and a number of improvements, with the aim of providing ever more precise and rich sound reproduction.

[New feature] In the R-1 NOS's digital processor, zero delay technology is applied, guaranteeing exact synchronization of data and clock, considerably reducing jitter.

[New feature] The galvanic isolator is applied before the DA conversion and analog parts to cleanly isolate all digital inputs and their processors for a clean sound.

[New feature] The DA-8 modules have been replaced by two DA-7 modules with 8 groups of R2R 24bit decoders and 4 DSD decoders operating in balanced mode.

[Update] The use of the latest stabilized discrete servo power supply considerably reduces noise and helps reduce the heat generated by the R-1. The analog circuits remain powered by a Class A regulated power supply. A total of 8 PSU groups are integrated to power the various stages of the R-1.

[Update] The design of the current signal transmission is entirely discrete, with no OPA in the signal path.

Discrete R2R DAC

A discrete R2R DAC is acknowledged to be superior to an integrated R2R chip assembly such as the PCM1704K or AD5791, offering a more natural high-midrange listening experience. The technical advantages are that R2R DACs filter out clock noise not found in analog signals and R2R DACs are less sensitive to jitter on 16bit definitions. The analog signal is theoretically more accurate than a DAC based on Delta Sigma technology.

An FPGA DSP processor

The FPGA DSP in the Audio-GD R-1 DAC overcomes the inaccuracy of resistors beyond 16/21bit. The result is high precision even in high definition 24bit 384khz. These technical qualities also include: better processing of SPDIF inputs (coaxial, optical) than the usual integrated interfaces (WM8505, DIR9001), thanks to faster computing power and FIFO buffer stages that drastically reduce jitter.

Pure Class A analog stages

Based on over 20 years of expertise, Audio-GD excels in creating analog stages without feedback. The R-1 DAC's output circuit benefits from this long and incisive research, with stages made entirely of sorted and matched discrete transistors. There are no surface-mounted components and a minimum of components in the signal path. The final buffer stages are made of high-bandwidth single-ended FET transistors on two parallel stages, guaranteeing low output impedance. This last part has no capacitors in the signal path. Of course, this converter also features high-speed, high-current ACSS outputs. In the spirit of "less is better", there are no relays on the analog circuit.

Low-noise, oversized linear power supply

A good DAC is nothing without a quality power supply producing the lowest possible parasitic noise. The R-1 features a triple-wound, low-radiation R-Core transformer for the digital, left and right analog stages. Each voltage is distributed over a total of 13 pure Class A regulation groups, producing very low noise and fast impulse response.

Specifications
Product type	DAC R2R
SNR	> 110dB
Output impedance	< 10Ω (RCA/ XLR)
Output level	RCA: 2.5V XLR: 5V ACSS: 2mA+2mA
Frequency response	20Hz - 20KHz (< -0.5dB)
THD+N	< 0.03%
Input sensitivity	0.5Vp-p (75Ω, Coaxial) 19 dBm (Optical) USB 1.0 - USB 3.0
USB compatibility	Windows, OSX, Linux, ISO
Supported sample rates	USB, IIS: PCM up to 32Bit 384kHz, DSD up to DSD512 Coaxial: PCM up to 24bit 192kHz

Specifications

Product type

DAC R2R

SNR

> 110dB

Output impedance

< 10Ω (RCA/ XLR)

Output level

RCA: 2.5V
XLR: 5V
ACSS: 2mA+2mA

Frequency response

20Hz - 20KHz (< -0.5dB)

THD+N

< 0.03%

Input sensitivity

0.5Vp-p (75Ω, Coaxial)
19 dBm (Optical)
USB 1.0 - USB 3.0

USB compatibility

Windows, OSX, Linux, ISO

Supported sample rates

USB, IIS: PCM up to 32Bit 384kHz, DSD up to DSD512
Coaxial: PCM up to 24bit 192kHz

General
Power suppply	220-240V AC 50/60Hz (100-120V AC 50/60Hz, selector inside)
Power consumption	12W
Dimensions	24028085mm
Color	Black
Package	1* Audio-GD DAC R-1 NOS 1* Mains power cable (EU plug) 1* USB-A to USB-B cable 1* Remote

General

Power suppply

220-240V AC 50/60Hz (100-120V AC 50/60Hz, selector inside)

Power consumption

12W

Dimensions

240*280*85mm

Color

Black

Package

1* Audio-GD DAC R-1 NOS
1* Mains power cable (EU plug)
1* USB-A to USB-B cable
1* Remote

Input	USB
Input	I2S
Input	SPDIF
Output	XLR
Output	RCA
Output	ACSS
DAC / ADC Chip	R2R LADDER DAC
Max sampling rate	DSD512
Max sampling rate	384kHz
Color	Black
Networking	No
Remote Control	No

Incredible DAC!
OK, cons first:
1/ clicking sound on digital coax cable connection when you switch from one sample rate material to another also from PCM to DSD.
This issue is not present on HDMI/I2S cable connection. Strange.
2/ Ridiculous burn-in time. DAC straight from the box sounds like broken one. Muddy, unclear, unpleasant. And all of this despite 100 hrs factory burn-in. I would send it back to seller, but before the purchase I made deep online research and all R1NOS users advised long burn-in time: minimum 600 hours. So I gritted my teeth and gave this DAC a chance and time to spread the wings.
It was real rollercoaster. One day DAC was sounding OK, another day excellent, next day - really poor.
But after approx 400 hours of burn-in sound started to be more stable and after 610 hours - just incredible!
Anyway: I've purchased this DAC 12/4/2025 and I'm able to use it normally just since yesterday: 21/7/2025. 600 hrs of burn-in is a MUST!
Now - pros:
1/ plenty of connection possibilities, including HDMI/I2S (best one!). Strongly advise to use this one! You will avoid clicks and the sound is definitely best.
2/ SOUND!!! Just unbelievable! Sweet, refined, rich, saturated, airy, delicate, nuanced, crystal clear. My system sounds like minimum 50 000€ stack and I paid in general approx 7000€ for all (some elements new, some second hand). Detail? Well... this is not delta/sigma. If you want detail, buy ESS. There will be detail, but there will be no music at all. This DAC is typical R2R - detailed enough. Anyway - for example articulation of guitar strings is fully satisfactionable.
I have just 2 things more to say:
1/ in its price this DAC is a STEAL!!! Totally non fatiguing yet absolutely crystal sound.
2/ this is cheapest Audio-gd DAC. If the price floor in this factory has so incredible quality, I would like to see the ceiling...
HIGHLY RECOMMENDED!!! (if you're happy to wait 600 hours)
Sound samples (all system elements in clip description):
HEADPHONES ON!!!
https://rumble.com/v6wi06o-dac-burn-in-is-over-.html
https://rumble.com/v6wi0rc-chinese-godfather-.html
https://rumble.com/v6wi1d4-leftist-waltz-live-.html
https://rumble.com/v6wj5au-big-in-japan-.html

Good job, Audio-gd! :)

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This review has been posted for AUDIO-GD R-1 NOS R2R Discrete DAC DSP FPGA USB Amanero HDMI I2S32bit 384kHz DSD512 Black