TEAC AI-503-A USB Integrated Amplifier

TEAC AI-503-A Integrated Amplifier features a dual-mono configuration supporting resolutions up to 11.2MHz DSD and 384kHz/32bit PCM, Separate DACs, Bluetooth receiver with LDAC/Qualcomm aptX support, TEAC-QVCS high-precision volume control circuit, high-output Class-D power amplifier, 2x 280mW headphone amp with discrete, push-pull circuit and twin analogue level meters with adjustable brightness.

VERITA AK4490 DACs

For the DAC chips, the highly-regarded VERITA AK4490 DACs are used. Along with native playback of 11.2MHz DSD signals through direct processing, a wide range of high-resolution audio sources (including 384kHz/32-bit PCM digital input) are supported. These DACs enable the reproduction of the finely etched detail and outstanding sense of stereo placement that are the hallmarks of quality high-definition high-resolution audio sources.

Dual-Mono Configuration

As well as helping deliver class-leading levels of power, the sophisticated dual-mono configuration also extends to the D/A converter and the preamp. The dual-mono layout incorporates two completely independent mono circuits for the left and right channels. Starting with the high-performance VERITA AK4490 D/A converters, this arrangement provides outstanding isolation between the two channels.

TEAC-QVCS Circuit

TEAC-QVCS (Quad Volume Control System) is an ingenious circuit with a fully-balanced design. It allows balanced processing of the audio signal at every stage, from immediately after digital-to-analog conversion until the signal reaches the volume amplifier.

Control signals simultaneously adjust the variable-gain amplifier-type volume controls of four independent circuits. This achieves a clear sound quality with outstanding channel separation. Level discrepancies between left and right channels at low volumes, which can be a particular issue during headphone listening, have been completely eliminated, so you can enjoy accurate audio even when using low-impedance in-ear monitors.

Built-in 44.1kHz and 48kHz clocks

The AI-503-A supports asynchronous transfer mode when connected by USB, allowing it to control PCM and DSD signals by synchronising them with its own clock (generated by a high-precision crystal oscillator) rather than synchronising with a computer clock signal that is invariably unstable and noisy.

Two dedicated internal clocks (running at 44.1kHz and 48kHz) are built in. By clocking signals that are a multiple of the clock frequencies to an audio-grade, high-precision crystal oscillator, featuring inherently low phase noise, the damaging effects of jitter on audio quality can be largely suppressed and the audio source can be reproduced more faithfully.

4 PCM and 2 DSD digital filters

Filter types include 4 PCM and an ‘off’ mode , as well as 2 DSD digital filters. You can use the remote control to set the optimal filter, according to the input file format and type of music. You can also change the filter during music playback so that you can fine-tune the audio quality.

Class D power amplifier 

TEAC AI-503-A incorporates a well-regarded high-output power amplifier made by ICEpower. This guarantees high-resolution playback of delicate signals as well as excellent linearity at high output levels. Using this power amplifier enabled the inclusion of a dual-mono circuit configuration in the DACs within the compact dimensions.

Toroidal-core Transformers

Efficient toroidal-core power transformers that can supply stable power are used. They are specifically designed to suppress magnetic flux leakage and prevent electromagnetically-induced noise, so can provide current that is always pure and stable.

USB input

The USB input supports resolutions up to 11.2MHz DSD and 384kHz/32-bit PCM. "DSD native playback" in which DSD is converted directly to analog without first being converted to PCM is also supported.

Bluetooth supporting LDAC

The onboard Bluetooth receiver supports LDAC and Qualcomm aptX as well as AAC and other wireless transmission of high-quality audio. LDAC enables the transmission of High-Resolution (Hi-Res) Audio content, even over a Bluetooth connection.

Pre-out Connectivity

The AI-503-A can also be used as a high-quality preamp. As the volume from the RCA output jacks can be varied, you can achieve a seriously upgraded audio system simply by connecting a power amplifier to the pre-out jacks. In addition, the unit has a pair of analog RCA input jacks, so you can also connect an analog turntable with a built-in phono EQ amplifier, such as a TN-350 or TN-570, a cassette deck, or other analog equipment.

Front digital input

The front digital input jack is a convenient way of connecting digital audio players with optical digital and analogue outputs. You can enjoy your favourite music already on your portable device through speakers or headphones, using the high-quality headphone amp.

TEAC-HCLD Circuit

The dedicated headphone amp employs Class AB operation, a discrete push-pull circuit and op amp. TEAC have applied all the expertise gained during the development of the UD-503 to give this model a circuit design that suppresses the occurrence of noise while maintaining the wide operational range of a Class-A amplifier. The fine details and nuances of music, captured in high-resolution audio sources, are conveyed in an untainted way.

Headphone amp stage

TEAC AI-503-A headphone output uses a circuit design with completely separated grounding for left/right channels from amp to the final 4-pole type jack. By completely separating the grounding of the left/right channels from the amplifier, channel separation is greatly increased and a much more transparent soundstage achieved.

2-stage gain switching function

The headphone amp output has a 2-stage gain-switching function. This enables optimal volume setting according to the impedance and efficiency of the connected headphones, using everything from low-impedance in-ear monitors to high-impedance 600Ω headphones.

Dual analogue level meters

Analogue level meters are built into the front and move in response to signal levels to emphasise the role of the unit as a piece of audio equipment. In addition to a dimmer function with four levels (bright, normal, dim, off) that allows you to adjust the brightness to match the lighting of the room, you can also turn off the operation of the level meters completely.

User interface design

TEAC pay great attention to each and every control, including an aluminium volume knob with firm torque and toggle switches that provide a sense of satisfying certainty in operation. The dedicated remote controller, which is topped with aluminium alloy exudes class. The remote control can adjust volume in steps as small as 0.5dB.

All-metal enclosure

The metal panelwork enclosure is resistant to external noise; the infiltration of electromagnetic noise generated by computers and other equipment is well-suppressed. This creates an electrically "clean" internal environment with little noise, even in outside environments that offer difficult conditions for audio equipment. The metal chassis also has 8mm-thick aluminum panels on both ends. These features prevent twisting and bending, resulting in a strong and stable body structure. The A4 footprint allows it to be placed on tables, sideboards and in other small spaces.

TEAC HR Audio app

TEAC HR Audio Player is a free, simple to use music playback software written specifically for TEAC, allows native playback of 11.2MHz DSD, 384kHz PCM and other high-resolution music files from MAC/PC.