32-band PEQ DAC

The SMSL SU-3 is a compact desktop digital-to-analog converter built around an AKM AK4496 DAC and XMOS XU-316 USB interface. It supports PCM up to 32-bit/768 kHz and DSD512, provides balanced XLR and single-ended RCA outputs, and adds 32-band parametric EQ. Dual femtosecond crystal oscillators and a dedicated USB power filtering stage support clean signal conversion in a chassis measuring just 4.57 x 1.57 x 3.43 in (116 x 40 x 87 mm).

AKM digital conversion

The SU-3 uses an AKM AK4496 DAC for digital-to-analog conversion. SMSL pairs the converter with a carefully designed signal path intended to reduce noise and harmonic interference, with specified THD+N of 0.00012% (-118 dB). Independent APx555B measurements shown by SMSL recorded XLR THD+N of 0.000114% on channel 1 and 0.000125% on channel 2 at approximately 4.1 Vrms.

High-resolution USB audio

An XMOS XU-316 USB controller handles high-resolution digital audio and supports PCM from 44.1 kHz through 768 kHz at up to 32-bit resolution. Native DSD support extends from 2.8224 MHz through 22.5792 MHz, corresponding to DSD64 through DSD512. Optical and coaxial inputs support PCM up to 24-bit/192 kHz.

Precision clocking

Two low-phase-noise femtosecond crystal oscillators provide clock references for the digital audio circuitry. Their role is to reduce timing error and phase noise during conversion, helping the DAC maintain stable signal timing across supported sample rates.

32-band parametric EQ

The SU-3 includes 32-band fine PEQ for detailed frequency-response adjustment. It can be used to tailor tonal balance for different headphones, speakers, rooms, or listening preferences. EQ settings are retained after power-off so saved adjustments can be recalled after a restart.

Balanced and single-ended outputs

Rear-panel outputs include balanced XLR and single-ended RCA connections. The balanced outputs are specified at 4 Vrms, while the RCA outputs provide 2 Vrms. This gives the SU-3 direct compatibility with a wide range of powered speakers, headphone amplifiers, preamplifiers, and other line-level audio equipment.

USB power filtering

A dedicated power-filtering stage is designed around USB operation, filtering noise, ripple, and electromagnetic interference from the incoming power supply. The SU-3 consumes less than 5 W during operation and less than 0.1 W in standby.

Compact aluminum chassis

The anodized aluminum alloy enclosure is CNC machined and measures 4.57 in wide, 1.57 in high, and 3.43 in deep (116 x 40 x 87 mm). At 0.683 lb (310 g), the SU-3 takes up little desk space and can be positioned flat, vertically, or on its side where suitable.

Broad computer support

USB audio uses asynchronous transmission and supports Windows 7, 8, 8.1, 10, and 11. Compatibility is also specified for macOS X 10.6 or later and Linux.

Product highlights

• AKM AK4496 DAC
  
• XMOS XU-316 USB audio controller
  
• PCM support up to 32-bit/768 kHz
  
• DSD support up to DSD512
  
• 32-band fine PEQ
  
• Dual low-phase-noise femtosecond crystal oscillators
  
• Balanced XLR line outputs
  
• Single-ended RCA line outputs
  
• Optical and coaxial digital inputs
  
• Asynchronous USB audio
  
• Specified 126 dB XLR dynamic range
  
• Specified 126 dB XLR SNR
  
• Compact CNC-machined aluminum chassis

Specs

• DAC chip: AKM AK4496
  
• USB controller: XMOS XU-316
  
• Inputs: USB-C, optical, coaxial
  
• Outputs: Balanced XLR, single-ended RCA
  
• Balanced output level: 4 Vrms
  
• Single-ended output level: 2 Vrms
  
• THD+N: 0.00012% (-118 dB) specified
  
• Dynamic range: 126 dB XLR, 123 dB RCA
  
• SNR: 126 dB XLR, 123 dB RCA
  
• USB transmission: Asynchronous
  
• USB bit depth: 1-bit to 32-bit
  
• Optical/coaxial bit depth: 16-bit to 24-bit
  
• USB PCM sampling rate: 44.1 kHz to 768 kHz
  
• USB DSD sampling rate: 2.8224 MHz to 22.5792 MHz
  
• Optical/coaxial sampling rate: 44.1 kHz to 192 kHz
  
• Operating system support: Windows 7, 8, 8.1, 10, 11, macOS X 10.6 or later, Linux
  
• Power consumption: Less than 5 W
  
• Standby power consumption: Less than 0.1 W
  
• Dimensions: 4.57 x 1.57 x 3.43 in (116 x 40 x 87 mm)
  
• Weight: 0.683 lb (310 g)

What’s included

• SMSL SU-3 digital-to-analog converter