SMSL SU-3 Desktop DAC Launches With 32-Band PEQ

The SMSL SU-3 was launched internationally today (September 23). The third generation of SMSL’s entry-level DAC restores a feature removed from the SU-2: the USB input. Its highlights include a 32-band parametric equalizer (PEQ), balanced XLR outputs, and an AKM DAC chip. Full details on this new SMSL release are provided below.

The SU-3 brings back the USB input, an AKM chip, and more

When the SMSL SU-2 was launched earlier this year, the main criticism concerned the removal of the USB input. The second generation offered only AES, optical, and coaxial inputs. The SU-3 now restores the USB input but removes the AES input.

Another change in the third generation of SMSL’s entry-level DAC concerns the DAC chip. The second generation used an ESS Labs DAC, but SMSL decided to return to AKM, the chip manufacturer used in the first generation. The SMSL SU-1 used the AK4493S, whereas the SU-3 incorporates the AK4496.

The SU-3 also returns to USB power, as used in the SU-1. The SMSL SU-2 featured an internal power supply with a C13 connection, commonly used with computer power supplies.

Balanced XLR outputs retained

The SU-3 retains the balanced analog XLR outputs found on the SU-2. This allows the desktop DAC to connect to an amplifier equipped with balanced XLR inputs.

Power conditioning for USB power

To power the SU-3 via USB, SMSL implemented a circuit designed to precisely filter noise, ripple, and electromagnetic interference. This stabilizes the voltage and current supplied to the DAC, providing “cleaner” power.

The manufacturer explains the benefits of the SU-3’s power supply implementation as follows:

“Even when powered solely through a standard USB interface, the chip, crystal oscillator, and decoding module can maintain stable operating conditions. As a result, its sound quality is readily comparable to that of conventional equipment with high-power supplies.”

A new feature: Parametric equalization (PEQ)

The SU-3 introduces a feature absent from both the SU-2 and SU-1: a parametric equalizer (PEQ). By accessing SMSL’s web app through a PC browser, users can adjust 32 bands in the parametric equalizer.

Femtosecond crystal oscillators to reduce jitter

To further improve the SU-3’s performance, SMSL implemented a pair of femtosecond crystal oscillators to reduce jitter [1]. Lower jitter improves the clarity of subtle details, sound naturalness, instrument separation, and the soundstage.

[1] Jitter is an unwanted variation in the timing at which the DAC reads an audio sample. Ideally, digital audio samples should be read and converted at perfectly regular intervals.

XMOS USB controller

To prevent audio and video from falling out of sync, SMSL incorporated the XMOS XU-316 USB controller. This results in extremely low audio transmission latency, allowing users to watch movies and play games with perfectly synchronized picture and sound.

SMSL SU-3 connections and physical buttons

The diagram below shows the SMSL SU-3’s connections and physical buttons.

SMSL SU-3: Specifications

• 32-band parametric equalizer (PEQ) support
• Analog outputs: Single-ended (SE) RCA and balanced XLR
• Balanced line output level: 4 Vrms
• Chassis material: anodized aluminum alloy
• Color: Black
• Compatible operating systems: Windows 7 / 8 / 8.1 / 10 / 11; Mac OS X 10.6 or later; Linux
• Digital inputs: USB, optical, and coaxial
• Dimensions: 116 × 40 × 87 mm
• Power consumption: 5 W
• Single-ended (SE) line output level: 2 Vrms
• Standby power consumption: 0.1 W
• Supported formats via the optical and coaxial inputs: PCM up to 24-bit/192 kHz
• Supported formats via the USB input: PCM up to 32-bit/768 kHz and DSD512
• THD+N: 0.00012% (−118 dB)
• USB controller chip: XMOS XU-316
• USB transmission: Asynchronous
• Weight: 310 g

Launch, pricing, and availability

The SMSL SU-3 is now available internationally in black for US$189.99 from the Shenzhenaudio store on AliExpress.

More affordable SMSL desktop DAC alternative with an AKM chip

If the SU-3 exceeds your budget, you can purchase the SMSL SU-1 desktop DAC, which features an AKM DAC chip. The SU-1 is available for US$79.99 from the Shenzhenaudio store on AliExpress.