High-performance VERITA AK4490 DACs support 11.2MHz DSD and 384kHz/32-bit PCM
|For DAC chips, which are the keys to digital audio, we have used VERITA AK4490 DACs, which are made by Asahi Kasei Microdevices Corporation and have an established reputation for use in high-end audio equipment.* The VELVET SOUND architecture provides the fine expressive capability suitable for the playback of high-resolution audio sources that reproduce sound waves outside the human audible range. Furthermore, a newly developed low distortion technology enables performance of S/(N+D) = 112 dB. This is the best level in the industry for a 120dB class DAC.
Not only is native playback with direct processing of 11.2MHz DSD signals possible, support is provided for an even greater variety of high-resolution audio sources, including 384kHz/32-bit PCM digital input. We have realized expression of the fine smooth detail and outstanding sense of sound placement that characterize high-resolution audio sources.
|*The AK4490 is a product in the Audio4pro™ family brand developed by Asahi Kasei Microdevices Corporation for professional audio equipment and high-end digital audio applications.|
Dual-monaural structure supports fully-balanced transmission and realizes further advancement
|Behind the expressiveness of the UD-503, which exceeds the level expected of its class, is an indulgent dual-monaural circuit structure that encompasses every aspect from the power and D/A sections to the analog output stage.
Starting with the toroidal core power transformers, which feature the ability to supply stable current, and the high-performance VERITA AK4490 DACs, the dual-monaural structure has a complete mono circuit for each channel. This prevents the signals from interfering with each other as much as possible. Interference is suppressed between the left and right channels, which is particularly important for headphone listening, so this unit can also be used as a high-performance headphone amplifier.
Furthermore, by processing the output signals of each channel completely with a differential from immediately after D/A conversion to the final output stage, common mode noise is removed and the sense of air that high-resolution audio has is not lost in transmission during balanced output.
In addition to 44.1kHz and 48kHz internal clocks, 10MHz external clock input is also supported.
|When connected by USB, rather than synchronizing with a computer clock that is unstable and noisy, the UD-503 supports asynchronous USB transfer mode, allowing it to control PCM and DSD signals by synchronizing with its own clock generated by its built-in high-precision crystal oscillator. Two dedicated internal clocks running at 44.1kHz and 48kHz are built in. By applying clock from an audio grade high-precision crystal oscillator, which features low phase noise, to input signals which that sampling frequency are whole number multiples, the effect of jitter on audio quality can be largely suppressed and the audio source can be reproduced faithfully.
In addition, with support for 10MHz external master clock input, synchronization with master clock signals of even higher precision is possible. By synchronizing with clock that has an even higher precision, you can enjoy changes in tone quality and improved audio quality that can be felt physically.
Enclosure designed with great attention to detail
The full-metal body realizes both vibration control and elegant style in an A4-size body that enables placement on a desktop
- The construction of the entire body from metal panels that are effective against external noise suppresses the penetration of electromagnetic noise emitted by computers and other devices. This realizes a clean internal environment with low noise even when the surroundings are hostile to audio equipment. The metal chassis is also wrapped from both sides with 8mm-thick aluminum panels, and a center beam connects the front and rear of the chassis. These features prevent twisting and bending to realize a strong and stable body.
In addition, the footprint that is the size of a page* allows it to be placed on tables, sideboards and other small spaces.
*Not including jacks, knobs and other protruding parts.
Symmetrically placed XLR output and RCA input and output jacks
The output jacks on the rear panel, including metal-plated XLR jacks for balanced output and RCA pin jacks for unbalanced output, have been symmetrically located for the shortest signal paths. The unit has been designed for connection with high-end equipment. For example, the left and right pin jacks have been placed with enough space between them to enable the connection of large-diameter RCA pin jacks.
In addition, three digital inputs on the rear panel (USB, coaxial and optical) are complemented by one (combined coaxial/optical connector) on the front. Starting with 192kHz/24-bit using the coaxial and optical digital inputs, the input of 2.8MHz DSD using DoP and other high-resolution signals is supported. The digital input on the front is a combined coaxial mini and optical mini connector, making it simple to connect a TEAC HA-P90SD or other portable digital audio player capable of digital output. (A coaxial-3.5mm mini conversion cable is included.)
Three supportive pinpoint feet that allow easy installation
The three-point support method used for the legs enables stable body installation without influence from even the slightest surface irregularities. An original structure that unifies the spike-shaped foot with the mortar-shaped foot-stand is used for each leg. Vibrations and resonance are reduced by supporting the body of the unit on pinpoints. This thoroughly eliminates mid and low frequency heaviness and murkiness and realizes improved resolution, which brings out the details of sounds and sound placement. Each pinpoint foot used on the UD-503 is composed of the foot (top of photograph) itself that is attached firmly to the chassis, and a foot base (bottom of photograph). The base flange (the outer rim of the mortar-shaped part) hangs from the flanges of three screws. Due to this structure, the interlocking flanges prevent the feet bases from falling off or shifting when the body of the unit is lifted. When the unit is placed, each spike point touches only the single deepest point in the mortar-shaped part of its base.
Although the pinpoint method has been called the ideal for audio equipment feet, complete installation had been extremely difficult. With this structure, we have made installation using this method simple.。
TEAC HR Audio Player, which supports 11.2MHz DSD playback on both Windows and Mac, provided for free
- 11.2MHz DSD files can be played back easily using Windows or Macintosh computers without making complicated settings. The next-generation of high-resolution audio sources can be enjoyed immediately. (When using a Windows computer, a separate driver must be installed.)