Gustard DAC-R26 II R2R ladder DAC (Demo)

Gustard R26 II

Discrete R-2R Network Streaming DAC

Gustard R26 II is a fully discrete R-2R DAC with integrated network streaming, designed with a focus on signal purity, precision, and analog sound quality. The entire design is built around proprietary modules, a separate power supply, and advanced clock management to ensure stable and consistent high-level performance.

Fully Discrete 26-bit R-2R Architecture

The R26 II uses Gustard's proprietary fully discrete R-2R resistor ladder DAC architecture in a new 26-bit implementation. Unlike Delta-Sigma-based solutions, the conversion here is performed directly from a digital signal to an analog voltage without noise shaping or high-frequency modulation. The result is a more organic, fluid, and analog sound character.

The discrete design places extremely high demands on component matching and PCB layout, and the R26 II is constructed with precision-selected components and very tight tolerances to achieve stability and uniform performance.

Native 1-Bit DSD – Direct DSD Mode

The DAC core supports true native 1-bit DSD, all the way up to DSD2048 via I²S. In Direct DSD Mode, the DSD bitstream is fed directly to the 1-bit switch array without internal PCM conversion or DSP manipulation.

This hardware-based decoding preserves dynamics, transient response, and the original Pulse Density Modulation (PDM) without compromise.

FPGA-Based Digital Processing

The R26 II is equipped with an FPGA platform that handles:

• Clock management

• 2nd-order PLL digital shaping

• DoP demodulation

• PCM / DSD path switching

This flexible and proprietary digital processing forms the basis for high signal integrity and precise timing across all input types.

GCLK-02 Clock Module & External 10 MHz Input

The internal GCLK-02 clock module uses advanced PLL technology with a locking accuracy of ±1 Hz, ensuring extreme frequency and phase precision.

In addition, the R26 II supports external 10 MHz clock reference input (BNC), so an external high-precision master clock can be used for further improved timing and sound quality.

Discrete Class-A LPF Output Stage

The analog output is built with a fully discrete Class-A Low Pass Filter (LPF), specifically tuned for the R-2R architecture.

Instead of integrated op-amps, discrete components are used, providing full control over bias, compensation, and harmonic structure. The result is improved transient response, more nuanced tone, and high thermal stability.

Dual Independent Power Supplies

The digital and analog sections are completely separated and powered by two dedicated toroidal transformers.

This physical and electrical separation reduces crosstalk and interference – including RF noise – and ensures a stable and low-noise operating environment for both digital and analog signal processing.

Network Streaming & Connectivity

The R26 II functions as a network streaming DAC and supports:

• Roon Bridge

• AirPlay

• UPnP

• Spotify Connect (via network bridge)

• NAA

In addition, Bluetooth 5.1 is offered, as well as USB, AES/EBU, Coaxial, Optical, and I²S (configurable pinout).

High-Resolution Support

• PCM up to 768 kHz (USB)

• PCM up to 1536 kHz (I²S)

• Native DSD up to DSD512

• Native DSD up to DSD2048 (I²S)

Design & Usability

The enclosure is made of solid aluminum with a focus on mechanical stability and effective shielding. The display offers three screensaver modes with adjustable brightness, and the unit supports remote control.

Balanced XLR and single-ended RCA outputs are available.