The Gustard R30 is a DAC, streamer and preamplifier based on an R2R ladder resistor network to offer high-precision digital-to-analog conversion. It supports PCM up to 32-bit 1536kHz and DSD up to DSD1024 for faithful and detailed reproduction. The extensive connectivity allows it to be integrated into a wide range of audio setups. Based on CelWare 3.x software, it supports Roon Bridge , AirPlay , HQPlayer NAA , UPnP , mConnect , Bubble UPnP , Spotify and QQMusic .
Gustard R30: 27-bit R2R DAC
The core of the R30 is based on a discrete 27-bit R2R architecture, where the signal is processed by a ladder resistor network instead of a conventional conversion chip. This approach allows for fully analog conversion without complex digital interpolation. Unlike delta-sigma DACs , which use noisy modulation and massive oversampling, R2R works directly at the native resolution of the signal.
The R30 implements 1-bit analog decoding , designed to handle the DSD stream purely in hardware without prior conversion to PCM . This preserves the integrity of the DSD signal and avoids distortion and artifacts associated with intermediate conversions. The device therefore supports native DSD1024 . This is accompanied by a specially optimized low-pass filter , which complements the conversion stage by ensuring a smooth and controlled frequency response.
Gustard R30: Latest generation digital filter
The R30 incorporates a newly developed digital filter that can upsample the signal while effectively reducing the associated noise. This processing stage also eliminates aliasing distortion , which can be present in the bandwidth and is inherent to the conversion process. The result is that the signal retains its integrity with a cleaner and more well-defined reproduction across the entire audible spectrum.
Gustard R30: OCXO clock and GCLK-02 module
The timing section is handled by a thermostabilized OCXO clock , which provides high precision and optimal stability over temperature variations.
The OCXO clock is paired with a GCLK-02 clock module , a high-performance clock frequency synthesizer that uses advanced PLL (Phase Locked Loop) technology to ensure stability and accuracy in the produced signal. The design of the module allows the use of either a local clock source (in this case the OCXO ) or an external 10MHz clock signal , providing a flexible and high-quality clock solution.
The R30 can also be synchronized to an external clock via its 50 Ω BNC input, which is compatible with either a square CMOS signal (0.2–3.3 V) or a sine wave (0.5–3.3 V).
Gustard R30: Gustard's FPGA
The R30 features a proprietary Gustard FPGA for signal reconstruction and advanced digital signal processing. It handles clock signal distribution and processing, PLL shaping, DoP demodulation , and switching noise reduction in PCM and DSD signals. This integration enables precise control of each stage, ensuring stable and optimized conversion.
Gustard R30: Analog preamplifier
In addition to the DAC function, the R30 can be used as an analog preamplifier. The volume control is based directly on its R2R network , allowing for lossless attenuation control. A bypass mode is available to disable the preamp section as needed. Thanks to this design, the R30 can be connected directly to a power amplifier or active speakers, simplifying integration into a high-fidelity audio system.
Gustard R30: CelWare 3.x
Based on an audio-optimized Linux kernel , the R30's CelWare 3.x software supports various protocols such as Roon Bridge , AirPlay , HQPlayer NAA , UPnP , Spotify , and others. Users can enable or disable these features via a browser by simply entering the address //x30.local .
Gustard R30: XMOS interface
The Gustard R30 is equipped with an XMOS XU216 USB interface that supports signals up to PCM 768kHz and DSD512 for superior audio transmission.
Gustard R30: Power supply
The R30 features two separate transformers to power the digital and analog sections independently, eliminating any mutual interference. Each channel is also equipped with dedicated filter capacitors, ensuring stable voltage and noise-free operation.