Now Available: D&A Alpha Desktop DAC/Amp
D&A Alpha desktop DAC and headphone amplifier
The D&A Alpha is a fully balanced desktop DAC and headphone amplifier built for listeners who want a single, well-engineered hub for headphones, powered speakers, and digital sources. It combines dual ESS ES9039Q2M DAC chips, a discrete fully balanced amplification stage, and a power system built around dual independent modules. The goal is straightforward—low noise, predictable behavior across loads, and enough output headroom to cover everything from sensitive IEMs to current-hungry planar headphones. Alpha supports USB, optical, coaxial, and Bluetooth inputs, and it can function as a headphone amplifier, a DAC feeding external gear, or a preamp for active monitors.
Balanced DAC architecture and decoding
At the center of Alpha’s digital stage are two ESS ES9039Q2M DAC chips configured in a true balanced layout. Each channel is decoded independently, which helps reduce crosstalk and preserves channel separation before the signal reaches the analog stage. This matters most in complex recordings, where small timing and level differences define spatial cues.
USB decoding supports up to 768kHz/32-bit PCM and native DSD512, while optical and coaxial inputs handle up to 192kHz/24-bit and DoP64. Full MQA decoding is available over USB, optical, and coaxial, with MQA-CD support over optical and coaxial. In practice, this allows Alpha to handle modern high-resolution libraries without relying on external decoding or software-side workarounds.
Signal integrity by layout
Alpha’s four-layer PCB is designed around signal isolation rather than digital correction. Critical audio paths are routed on protected inner layers, while grounded outer layers act as shielding against interference. The board separates digital control, high-speed data, analog audio, and power into distinct domains, each with its own ground reference and star-routed power.
For timing-sensitive sections, delay is controlled to within ±5ps across differential pairs. Jitter is the small timing uncertainty present in any digital system—the lower it is, the more precisely transients and spatial information are preserved. By controlling it at the layout level, Alpha avoids relying on aggressive post-processing to clean up the signal later.
Power delivery with headroom in mind
The Alpha uses two independent Mean Well power modules—one dedicated to the DAC section and one to the headphone amplifier—followed by discrete regulation and additional filtering. This separation reduces interaction between digital and analog stages under load. When current demand increases, such as during low-frequency transients at higher listening levels, the rails remain stable.
This approach supports Alpha’s measured performance, including THD+N as low as 0.00006% (-123.5dB) from the XLR outputs and a signal-to-noise ratio up to 131dB. These figures translate to a low noise floor, meaning quiet details remain audible without hiss or grain.
Fully balanced headphone amplification
Alpha’s headphone amplifier is built around a fully balanced, discrete topology with multiple gain levels. Balanced output power reaches up to 9000mW per channel at 32Ω, scaling appropriately for higher-impedance loads. Gain steps are designed to keep the usable range of the volume control consistent whether you are using IEMs or full-size headphones.
Output impedance is near zero at the headphone outputs, which helps maintain predictable frequency response across different headphone designs. The result is an amplifier that does not impose a character of its own and remains stable across a wide range of loads.
Connectivity that reflects real systems
Inputs include USB, optical, coaxial, and Bluetooth 5.3 with support for SBC, AAC, aptX, aptX HD, and LDAC. Bluetooth uses a concealed helical antenna designed to improve reception without external protrusions. Outputs include 4.4mm balanced and 6.35mm single-ended headphone connections, along with XLR and RCA line outputs.
Line out can operate as a fixed DAC output or as a preamp with volume control, making Alpha suitable for driving active speakers directly. This flexibility allows it to sit at the center of a desktop system without requiring additional switching hardware.
Protection and long-session stability
Alpha includes thermal management and circuit protection designed for everyday use. Distributed cooling keeps internal temperature variation within ±2°C, while DC, overvoltage, and overload protection safeguard connected equipment. Pop-free relays and multi-phase monitoring help prevent transients when switching modes or powering the unit on and off.
These are quiet design choices, but they matter when a component is used daily and left powered for long listening sessions.
How it compares to the Alpha Pro
Compared to the original Alpha Pro, the Alpha takes a more focused approach. The Alpha Pro was designed as a full system hub, with a flagship ES9039MSPRO DAC, true analog preamp functionality, and support for analog sources like turntables and tape decks. The Alpha removes that analog layer and centers the design around modern digital playback, using dual ES9039Q2M DACs, a simplified signal path, and a smaller chassis. The result is a unit that prioritizes desk-friendly size, higher peak headphone output, and a cleaner digital-first architecture for listeners who do not need analog inputs or a dedicated preamp stage.
