Audirect ATOM4 ESS9281AC PRO Portable DAC Amp

Audirect ATOM4 is an ultra-portable USB DAC and headphone amplifier designed for high-resolution music playback on compatible smartphones, tablets, and computers. Featuring the ESS9281AC PRO DAC chipset, dual RT6863C operational amplifiers, and both 3.5mm single-ended and 4.4mm balanced outputs, it brings dedicated Hi-Fi audio processing to a compact metal body.

Audirect ATOM4 ESS9281AC PRO Portable DAC Amp Overview

The Audirect ATOM4 Portable DAC Amp combines digital-to-analog conversion and headphone amplification in a lightweight USB-C device. It supports PCM playback up to 32-bit/768kHz and DSD512, making it suitable for listeners who use compatible high-resolution music files and wired IEMs or headphones.

Available in Bangladesh at Gadget Breeze, the ATOM4 offers two headphone output options, a dedicated amplification circuit, and plug-and-play USB connectivity for convenient portable listening.

Key Features

• ESS9281AC PRO DAC: High-performance digital-to-analog conversion for detailed high-resolution audio playback.
• Dual RT6863C Amplifiers: Two operational amplifiers integrated into the headphone amplification architecture.
• PCM 32-bit/768kHz: Supports high-resolution PCM decoding up to 32-bit/768kHz.
• DSD512 Support: Compatible with DSD audio playback up to DSD512.
• 4.4mm Balanced Output: Dedicated balanced headphone connection with a rated output voltage of up to 4.2Vrms.
• 3.5mm Single-Ended Output: Standard headphone connection with up to 2Vrms output voltage.
• Independent Circuit Design: Optimized digital and analog power sections intended to reduce interference.
• Low Distortion: Manufacturer-reported THD+N of 0.0004%.
• USB-C Connectivity: Convenient digital audio input for compatible smartphones, tablets, and computers.
• Compact Metal Body: Durable construction with an approximate weight of just 19g.
• Plug-and-Play Operation: Designed for convenient use with compatible USB audio devices.

Technical Specifications

• Brand: Audirect
• Model: ATOM4 / Atom 4
• Product Type: Portable USB DAC & Headphone Amplifier
• DAC Chipset: ESS9281AC PRO
• Operational Amplifiers: Dual RT6863C
• Digital Input: USB Type-C
• Headphone Outputs: 3.5mm Single-Ended / 4.4mm Balanced
• PCM Decoding: Up to 32-bit/768kHz
• DSD Decoding: Up to DSD512
• 3.5mm Output Voltage: Up to 2Vrms
• 4.4mm Balanced Output Voltage: Up to 4.2Vrms
• 3.5mm Output Power at 32Ω: ≥126mW
• 4.4mm Output Power at 32Ω: ≥137mW
• 3.5mm Output Power at 600Ω: ≥7mW
• 4.4mm Output Power at 600Ω: ≥29mW
• Signal-to-Noise Ratio: Approximately 119dB
• THD+N: 0.0004%
• Frequency Response: Within ±0.08dB up to 40kHz
• Body Material: Metal
• Weight: Approximately 19g
• Power: USB Bus-Powered
• Built-in Battery: No
• Color: Grey

ESS9281AC PRO High-Resolution DAC

At the center of the Audirect ATOM4 is the ESS9281AC PRO DAC chipset, which converts digital audio from compatible USB devices into an analog signal for wired headphones and earphones.

With support for PCM up to 32-bit/768kHz and DSD512, the ATOM4 can handle compatible high-resolution audio files without requiring a separate desktop DAC. Actual playback resolution depends on the source device, application, and audio file.

Dual RT6863C Headphone Amplification

The ATOM4 uses two RT6863C operational amplifiers as part of its dedicated headphone amplification system. This architecture provides additional amplification capability compared with a basic passive USB audio adapter.

The design is suitable for a variety of wired IEMs and compatible headphones, although actual driving performance depends on headphone sensitivity, impedance, and the selected output.

3.5mm Single-Ended and 4.4mm Balanced Outputs

The Audirect Atom 4 DAC Amp includes both a conventional 3.5mm headphone output and a 4.4mm balanced output, allowing listeners to connect compatible audio equipment without changing DAC devices.

• 3.5mm Single-Ended: Up to 2Vrms, with a rated output of at least 126mW at 32Ω.
• 4.4mm Balanced: Up to 4.2Vrms, with a rated output of at least 137mW at 32Ω.

The 4.4mm connection requires a compatible balanced headphone cable. A conventional 3.5mm headphone plug should not be connected using an incompatible balanced adapter.

Optimized Digital and Analog Circuit Design

Audirect ATOM4 uses a circuit architecture designed to manage digital and analog signal processing separately. Its internal power and signal arrangement is intended to help minimize interference and maintain consistent audio performance.

The reported 0.0004% THD+N specification reflects the device’s low-distortion design under the manufacturer’s stated measurement conditions.

Ultra-Portable 19g Metal Construction

Weighing approximately 19 grams, the ATOM4 is designed for everyday portable use. Its compact metal housing makes it easy to carry alongside wired earphones, a smartphone, or a laptop.

Because the device draws power through USB, it does not require a separate internal battery or charging routine.

USB-C Plug-and-Play Connectivity

The Audirect ATOM4 connects to compatible USB-C devices and functions as an external USB audio DAC. It can be used with supported Android devices, computers, and other digital audio sources that provide USB audio output.

Compatibility with individual smartphones, operating systems, adapters, and playback applications may vary. Devices with Lightning connectors may require an appropriate USB audio adapter.

Audirect ATOM4 Price in Bangladesh

Looking for the Audirect ATOM4 price in Bangladesh? Explore this compact Hi-Res USB DAC and headphone amplifier at Gadget Breeze. Discover more portable DACs, headphone amplifiers, and wired audio accessories in our DAC & Headphone Amplifier collection.

Frequently Asked Questions

Which DAC chip does the Audirect ATOM4 use?

The Audirect ATOM4 features the ESS9281AC PRO DAC chipset and dual RT6863C operational amplifiers.

Does the Audirect ATOM4 support 4.4mm balanced headphones?

Yes. It includes a 4.4mm balanced headphone output alongside a 3.5mm single-ended output.

What is the maximum supported audio resolution?

The ATOM4 supports PCM decoding up to 32-bit/768kHz and DSD playback up to DSD512.

Does the Audirect ATOM4 have a built-in battery?

No. The ATOM4 receives power through its USB connection to a compatible source device.

Can I use the ATOM4 with an Android phone?

Yes, provided the Android phone supports compatible USB audio output through its USB-C connection.

Is the Audirect ATOM4 a Bluetooth DAC?

No. The ATOM4 is a wired USB DAC and headphone amplifier, not a Bluetooth receiver.