The U26 USB Audio system was jointly developed by Gustard and Italy’s Amanero. Its NXP i.MXRT1011 processor with ARM Cortex M7 architecture delivers high processing performance and low latency, allowing high-sample-rate PCM and DSD data streams to be handled with stability and reliability.

The Gustard U26 offers broad compatibility, from conventional CD-quality recordings to the highest-resolution digital formats. Thanks to its USB Audio Class 2 connection, it can be integrated easily into modern Hi-Fi and audiophile systems.

It supports PCM sample rates from 44.1 kHz to 1536 kHz at resolutions of up to 32 bit. For DSD, it supports DSD64 to DSD512 in DoP mode and DSD64 to DSD2048 in native mode. The unit provides I2S, AES/EBU, coaxial, and optical digital outputs, ensuring compatibility with a wide range of DACs.

The accuracy of digital data transmission is influenced significantly by clock stability. The Gustard U26 uses an advanced clocking system and digital signal shaping to maintain precise timing, which is especially important when transmitting high-resolution audio signals.

The temperature-controlled OCXO oscillator provides frequency stability of approximately ±0.1 ppm and is complemented by high-performance K2 PLL technology. The system uses low-phase-noise reference clocks at 98.3040 MHz and 90.3168 MHz, while the CPLD circuitry reshapes the isolated IIS signal to reduce the likelihood of timing errors.

The Gustard U26 uses full galvanic isolation to separate the USB source side from the digital audio circuitry. This reduces the transmission of electrical interference caused by ground loops, common-mode noise, and the computer’s USB connection.

The built-in linear power supply is based on an audio-grade toroidal transformer and is complemented by multiple independent power circuits, discrete regulation, and ultra-low-noise LDO regulators. The USB interface, digital circuitry, and clock generator each receive separate power, while the main filter capacitors provide a total capacitance of 80,000 µF to support stable operation.

The Gustard U26 does not perform digital-to-analogue conversion; instead, it is designed to transmit the digital signal as accurately as possible. Its precision clocking system, galvanic isolation, and multi-stage power supply work together to preserve digital signal integrity.

Low jitter, stable timing, and reduced electrical noise provide favourable operating conditions for the connected D/A converter. These engineering solutions contribute to reliable system operation, especially during high-resolution digital playback.