GUSTARD R30 Fully Discrete R2R Network Streaming DAC

GUSTARD R30 Discrete R2R Network Streaming DAC

The GUSTARD R30 is a flagship fully discrete R2R ladder network streaming DAC for listeners who want digital done differently. Instead of delta-sigma toggling, its resistor ladder converts digital signals directly, producing a natural, detailed sound free of the digital edge. Around this core sits serious engineering – true 1-bit DSD decoding, FPGA-based clock management, a self-developed network bridge, and a discrete Class-A analog output stage.

Fully Discrete R2R Ladder Architecture

The R30’s self-designed discrete R2R module converts digital signals directly through a precision-matched resistor ladder network. This demands extreme resistor matching and stability, but it pays off with a more organic, analog-like conversion that avoids the high-frequency switching artifacts of conventional delta-sigma DACs.

True 1-Bit DSD Decoding

Native support for DSD1024 handles data density 1,024 times that of CD audio. In DIRECT DSD mode, the bitstream bypasses PCM conversion entirely and is decoded straight through a 1-bit switching array, preserving micro-details and timing integrity for an extremely detailed, dynamic presentation.

FPGA Digital Filtering with Triple Modes

Three filter modes – Linear Sharp, Minimum Slow, and Super Slow – let you shape the sound to your taste. Built on adaptive multi-order algorithms, the filtering reduces in-band aliasing noise while enhancing resolution and dynamics, free from the harshness found in conventional DACs.

OCXO & GCLK-02 Precision Clocking

An SC-cut crystal OCXO clock keeps jitter to imperceptible levels thanks to exceptional thermal stability and stress resistance. The GCLK-02 clock module with proprietary PLL achieves 1Hz sync-lock precision, and a dedicated 10MHz BNC input accepts an external master clock for reference-grade systems.

Network Bridge Built for Music

The self-developed CelWare-based network bridge strips away non-audio processes to minimize jitter and latency. Protocol support includes Roon Bridge, AirPlay, HQPlayer NAA, UPnP/DLNA, Spotify Connect, mConnect, BubbleUPnP, and QQMusic, with web-based control via //r30.local.

Discrete Class-A Analog Stage

Instead of integrated op-amps, the R30’s discrete Class-A low-pass filter stage lets each component be tuned individually, giving better control of frequency response, harmonic character, and transient handling for a rich, natural tonal balance.

Passive Relay Preamplifier

With its R2R relay-based volume control, the R30 doubles as a passive analog preamp. Switch into pure bypass mode to use it strictly as a DAC, or connect it directly to powered monitors or a power amplifier and control volume remotely.

Comprehensive Connectivity

Inputs cover USB (XMOS XU216 with isolation), coaxial, optical, AES/EBU, dual I²S with adjustable pinout, LAN, and a TF card reader. Outputs include balanced XLR (5.1Vrms) and unbalanced RCA (2.5Vrms), both 100Ω, plus trigger in/out for system integration.

Measured Performance

Reference-grade measured performance: THD+N ≤0.00145% @ 1kHz, SNR >121dB, dynamic range >123dB, crosstalk −139dB @ 10kHz, and a frequency response of 20Hz–20kHz within ±0.2dB – clean, transparent conversion across the whole band.

Specifications

• DAC Architecture: Fully discrete R2R ladder network, 27-bit
• DSD Support: Native DSD1024 via I²S (true 1-bit); DSD512 via USB
• PCM Support: Up to 1536kHz via I²S; 768kHz via USB
• Digital Filters: FPGA NOS + triple modes: Linear Sharp, Minimum Slow, Super Slow
• Clock System: SC-cut OCXO + GCLK-02, PLL 1Hz sync-lock; external 10MHz BNC input (50Ω, 0–20dBm)
• Dynamic Range: >123dB
• Signal-to-Noise Ratio: >121dB
• THD+N: ≤0.00145% @ 1kHz
• Crosstalk: −139dB @ 10kHz
• IMD: ≈0.002% @ −1dBFS
• Analog Outputs: XLR 5.1Vrms + RCA 2.5Vrms (fixed or relay volume controlled, 100Ω)
• Digital Inputs: USB (XMOS XU216), Coaxial, Optical, AES/EBU, Dual I²S, LAN, TF card reader
• Streaming Protocols: Roon Bridge, AirPlay, HQPlayer NAA, UPnP/DLNA, Spotify Connect, mConnect, BubbleUPnP, QQMusic (CelWare)
• Preamplifier: R2R relay-based passive volume control with pure bypass mode
• Trigger: Trigger in/out
• Power: AC 115V/230V, 50/60Hz; consumption <35W
• Dimensions (W×H×D): 430 × 300 × 80 mm (94mm with feet)
• Weight: 10.0 kg
• Colors: Black, Silver

What's Included

• GUSTARD R30 discrete R2R DAC
• Remote control
• Power cable
• User manual