As digital audio data travels from a computer to the UD-301-X via a USB cable, timing control for sending/receiving data packets is defined by the UD-301-X’s internal clock which is much more accurate than that of most computers. This asynchronous transfer mode theoretically eliminates signal-compromising jitter, and allows digital audio signals to travel in electrically ‘cleaner’ conditions.

When handling digital audio signals of 96kHz or less, you are able to up-convert them to double or quadruple the original signal sampling frequency. Even when playing back a conventional CD (which is 44.1kHz), a smoother analogue audio signal is obtained by up-converting to a higher sampling frequency. This up-conversion function can be disabled, according to the user’s preference.

In order to process Hi-Res audio data under the best conditions, the UD-301-X employs a dual monaural circuit design whereby each of the left and right channels comprises its own single monaural circuit. This circuit design avoids mutual interference between left and right channels and enables improved stereo playback.

At the heart of its digital audio section, the UD-301-X uses a pair of 32-bit processing DACs (digital to analogue converters), namely BurrBrown PCM1795s, one for each channel. These high-performance DACs are capable of processing large amounts of data such as DSD128, rendering more accurate playback of Hi-Res audio sources.

On the analogue processing side, key to defining final sound quality, the MUSES8920 Op-amps developed by New Japan Radio Corporation are employed to process the I-V conversion which turns output current from the DACs into voltage signals. A dual-monaural approach is also applied to this stage of processing.

When listening to Hi-Res music via the UD-301-X’s dual-monaural headphone amplifier circuit, the CCLC (Coupling Capacitor-Less Circuit) delivers a rich bass sound and quick transient responses. Conventional headphone amplifier circuits cannot avoid reduction of low frequencies and misalignment of phase caused by high-pass filtering within capacitors as they couple output stages.

In addition to its dual monaural headphone amplifier circuit design, the UD-301-X further strengthens its credentials as a headphone amplifier by offering the ability to disable XLR and RCA outputs on the rear panel. This limits power supply to the headphone amplification process, so maximizing its potential for headphone output. The UD-301-X offers ease of use as a headphone amplifier because the headphone volume is always varied by the master volume control on the front panel, regardless of the output mode (fixed, variable or disabled).

The UD-301-X features an energy-efficient Toroidal-core power transformer to deliver plenty of stable current to every single part of the circuit, including two high-performance DACs (digital to analogue converters) that carry out ultra-high-speed processing. Even when there are sudden dynamic swings, where large amounts of current are required instantly, the UD-301-X’s power supply will prove equal to the task.

A 215mm width and 238mm depth creates a footprint that allows you to place the unit in the smallest of spaces, while the full-metal body provides excellent rigidity and minimizes the adverse effects of vibration on final sound quality.

The UD-301-X is capable of working as a high-performance DAC with professional audio equipment and high-end audio units, as well as with consumer hi-fi components, thanks to its pair of XLR Balanced output terminals.

The output from both XLR Balanced and RCA Unbalanced outputs can be set to, fixed, variable or disabled, depending on your needs. This flexibility, among other things, allows you to connect to power amplifiers for a separates-based system or, indeed, active speakers when the unit is set to variable mode.