SMSL SU-2 ES9039Q2M DAC

The SMSL SU-2 is a compact, fully-balanced digital-to-analog converter designed for monitoring, desktop audio, and active speaker systems. It offers clean signal delivery, stable connectivity, and measurable performance: AES/EBU input, balanced XLR output, and a low-noise analog stage built around four OPA1612A op-amps. 

Fully balanced signal path

The SU-2 is designed around a fully-balanced architecture, from digital input through analog output. Balanced XLR outputs reduce noise over longer cable runs and help preserve signal integrity when feeding active monitors or balanced amplifiers. 

AES/EBU connectivity for stable digital input

An AES/EBU input provides a professional-grade digital connection with strong noise rejection and clock stability. It's great for monitoring chains and desktop systems where reliability matters. Coaxial and optical inputs are also available for broader source compatibility.

High-performance ES9039Q2M DAC architecture

The SU-2 uses the ES9039Q2M DAC chip, chosen for its low distortion and high dynamic range. Measured THD+N reaches as low as 0.00006 percent, with SINAD up to 123.5 dB on balanced output.

Four OPA1612A op-amps for low-noise amplification

The analog stage uses four OPA1612A operational amplifiers arranged in a symmetrical layout. This design prioritizes channel matching and low crosstalk. The result is stable linear amplification across a wide bandwidth, with consistent left-right balance and controlled noise.

Clear visual indicator system

The front-panel indicator array shows input selection, signal lock status, channel activity, and sampling rate at a glance. Sampling rate changes are briefly indicated, while left and right channel indicators respond to incoming audio. It is functional feedback, not decoration.

Compact, desktop-friendly design

The SU-2 measures 5.9 inches wide, 1.7 inches tall, and 5.2 inches deep (150 × 42.5 × 133.1 mm). It fits easily on a desk or shelf without crowding other gear. Power-off memory and automatic input detection reduce the need for repeated adjustments.

Designed for monitoring and near-field systems

With balanced outputs, low idle noise, and stable clocking, the SU-2 is well suited for near-field monitors and compact monitoring chains. AES/EBU input supports longer transmission distances, making it practical for desktop studios and workspaces where speakers are not right next to the source.

Product highlights

• Fully balanced DAC with XLR and RCA outputs
  
• AES/EBU, coaxial, and optical digital inputs
  
• ES9039Q2M DAC with low measured distortion
  
• Four OPA1612A op-amps in the analog stage
  
• Front-panel indicators for input, lock, channels, and sampling rate
  
• Compact metal enclosure for desktop use

Specs

• Digital inputs: AES/EBU, optical, coaxial
  
• Analog outputs: XLR, RCA
  
• Output level: 15.4 Vrms balanced (4.7 Vrms XLR), 2.3 Vrms RCA
  
• THD+N: 0.00006 percent XLR, 0.00008 percent RCA
  
• Dynamic range: 130 dB XLR, 126 dB RCA
  
• Signal-to-noise ratio: 130 dB XLR, 126 dB RCA
  
• Bit depth: 16-bit to 24-bit PCM, 1-bit DSD
  
• Sampling rates: PCM 44.1 kHz to 192 kHz, DSD64 via DoP
  
• Power consumption: under 2.3 W
  
• Standby power: under 0.1 W
  
• Size: 5.9 × 1.7 × 5.2 in (150 × 42.5 × 133.1 mm)
  
• Weight: 1.17 lb (532.6 g)

What’s included

• SMSL SU-2 DAC
  
• AC power cable
  
• Documentation