TEAC UD-503 Dual-Monaural USB DAC with Full Balanced Headphone Amp

Sku #J36124000000000

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Dual-monaural USB DAC with built-in fully-balanced/parallel-unbalanced headphone amplifier.

The UD-503 delivers world-class digital audio conversion in an ultra high-fidelity design that will easily fit into any home audiophile system. The UD-503 also features a built-in headphone amplifier that will bring your headphones to life, maximizing their full potential. The reason the UD-503 sounds so good is TEAC used VERITA AK4490 DACs, which 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. 

Dual-Monaural Structure Supports Fully-Balanced Transmission
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.

10MHz External Clock Input 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.

Preamp Circuits Use TEAC-QVCS High-Precision Volume Control 
The UD-503 can also be used as a preamp. One pair of XLR balanced outputs and one pair of RCA unbalanced outputs and included and can be set to either an adjustable or a fixed volume level, allowing a simple system to be put together in combination with a power amplifier or active speakers. We have even considered connection of record players such as the TEAC TN-300 turntable, cassette decks and other analog sources with line outputs by also including one pair of analog RCA inputs.

For the preamp circuit, TEAC utilized the TEAC-QVCS (Quad Volume Control System), which is a circuit with a fully-balanced design that uses balanced processing of the audio signal at every stage from immediately after conversion from digital to analog until it reaches the volume amplifier. Control signals transmitted from the volume knob simultaneously adjust the variable gain amp type volume controls for a total of four independent circuits—positive and negative for both of the left and right channels. Using this system, the unnecessary manipulation of audio signals is eliminated, and the left/right and positive/negative independence of the audio signals is preserved, achieving clear sound quality with outstanding channel separation. (This does not apply when using unbalanced analog input.)

Headphone Amplifier with Discrete Construction
The connection of balanced drive headphones is enabled by also using for headphone output TEAC HCLD circuits that are for line output and are composed of 4 output transistors each for both left and right channels. Furthermore, even during single end use, drive that is much stronger than an ordinary single end headphone amplifier is possible by making these transistors operate in parallel. In this unique circuit design, due to the AB class amplifier that greatly expands the A class operating range, A class operation is used for most of the range used in ordinary headphone listening. The potentials of various types of headphones can be brought out, starting with 600Ω high-impedance headphones.

On the front of the unit, two 3-pole TRS (standard stereo) jacks are provided as headphone outputs. These can be switched between three types of drive operation. In addition to connecting balanced drive headphones, you can also use unbalanced drive to connect two pairs of ordinary headphones, as well as use active ground drive, which can further decrease noise during silences and enhance the expressiveness of delicate sounds.

  • USB DAC supports 11.2MHz DSD and 384kHz/32-bit PCM
  • Dual-monaural circuit structure used from the power supply to the digital and analog sections
  • Both left and right channels have their own high-end AK4490 DACs
  • Two high-capacity toroidal core power transformers—one each for left and right channels
  • Isolation circuit that completely separates the digital and analog sections electrically
  • 4 TEAC HCLD buffer amplifiers, which are current-enhancing output buffer circuits, are used for the line amplifiers
  • Up-conversion to formats up to 12.2MHz DSD and 384kHz/32-bit PCM using an FPGA (programmable IC) that utilizes a fluency function
  • Two types of DSD filter and four types of PCM digital filter, as well as an OFF mode
  • 10MHz external clock input supported (available during USB asynchronous transmission)
  • Two high-precision internal clocks—one each dedicated to 44.1kHz and 48kHz signals (available during USB asynchronous transmission)
  • One pair of RCA analog unbalanced inputs
  • Volume output can be set to fixed, fixed +6dB or variable for the one pair of XLR analog balanced outputs and one pair of RCA analog unbalanced outputs
  • TEAC QVCS high-precision volume circuit
  • Large digital volume display with excellent visibility and remote control with one-button operation of various functions
  • OELD display shows input signal type and various settings (with 3-level dimmer and off functions)
  • Fully-balanced drive headphone amplifier with discrete construction and maximum output of 700 mW + 700 mW
  • Headphone amplifier can be switched among 3 drive types: unbalanced, balanced and active ground
  • Digital inputs on the back include one USB, one coaxial and one optical
  • Combined coaxial mini/optical mini digital input connector on front is convenient for digital input from portable devices
  • Low power consumption design and automatic power saving function meet modern expectations
  • The full-metal body realizes both vibration control and elegant style in an A4-size body that enables placement on a desktop
  • TEAC original design for three-point support using pinpoint feet with attached bases

The ultimate in home digital audio conversion, order the TEAC UD-503 today!

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