SMSL R100: R2R DAC with PEQ for $289

The SMSL R100 was launched today (September 9) internationally and in mainland China. The R100 is SMSL’s new desktop DAC, featuring a pair of AD1861-J R2R chips from Analog Devices. Other highlights include an aluminum alloy chassis and the ability to save equalization profiles created using a parametric equalizer (PEQ). See below for full details on SMSL’s latest release.

R100 offers R2R architecture and PEQ at a low price

One of the most affordable desktop DACs with an R2R architecture previously available was Gustard’s Audalytic DR70, priced at US$359.99. However, with the arrival of the SMSL R100, Gustard’s R2R desktop DAC has lost its position.

The SMSL R100 is available internationally for US$289. However, the lower price is likely attributable to its R2R DAC implementation, which was not developed in-house by SMSL.

How the R2R DAC used in the R100 differs from competing designs

SMSL chose to use a pair of AD1861-J R2R DAC chips manufactured by Analog Devices. This chip is listed as obsolete on the manufacturer’s website and was introduced in the 1990s.

Manufacturers such as FiiO, iBasso, and Cayin have opted to use discrete resistor networks. Consequently, each has developed its own R2R DAC rather than relying on off-the-shelf solutions. This certainly increases the final price of products based on R2R architecture, but it provides greater flexibility in tuning the DAC.

Improvements implemented by SMSL to enhance the R100’s performance

As with all R2R DACs, distortion issues arise as temperature increases, causing increased jitter [1]. To mitigate this in the R100, SMSL developed a high-precision S/PDIF digital filtering algorithm. The manufacturer describes its solution as follows:

“This algorithm extensively optimizes digital signal transmission logic, suppressing and reducing jitter.”

[1] Jitter is an unwanted variation in the timing at which the DAC reads an audio sample. Jitter occurs when the time it takes for the digital signal to reach the DAC varies during music playback.

Equalization profiles created using a parametric equalizer (PEQ)

Through a web app, SMSL allows users to create equalization profiles for the R100 using a parametric equalizer (PEQ).

Users can save two equalization profiles and operate the R2R DAC without equalization. This allows switching between different equalization profiles with a single button press.

Aluminum design with transparent windows

Instead of using a conventional, fully enclosed aluminum alloy chassis, SMSL chose to add two transparent windows to the top of the R100. This makes it possible to see the components soldered to the R2R DAC’s circuit board.

SMSL R100 connections and buttons

The image below shows the buttons and display on the front of the R100, as well as the connections on the rear of SMSL’s R2R DAC.

SMSL R100: Specifications

General specifications

• Analog outputs: One single-ended (SE) RCA output and one balanced XLR output
• Compatibility (via USB): Windows (driver installation required), Mac OS X and Linux (no driver installation required)
• Digital inputs: USB, optical, and coaxial
• Dimensions (width × height × depth): 170 × 39.8 × 136 mm
• Power consumption: 2.6 W
• Standby power consumption: < 1 W
• Weight: 712 g / 1.57 lb

Audio specifications

• DSD support (optical, coaxial): DSD64 via DoP
• Output impedance: 33 Ω
• Sampling rate (optical, coaxial, PCM): 44.1 to 192 kHz
• Sampling rate (USB, DoP): 2.8224 to 11.2896 MHz
• Sampling rate (USB, DSD): 2.8224 to 22.5792 MHz
• Sampling rate (USB, PCM): 44.1 to 768 kHz
• Total harmonic distortion + noise (THD+N): 0.003% (−90 dB)

Single-ended (SE) RCA output

• Output voltage: 1.75 Vrms
• Dynamic range: 108 dB
• Signal-to-noise ratio: 108 dB

Balanced XLR output

• Output voltage: 3.5 Vrms
• Dynamic range: 107 dB
• Signal-to-noise ratio: 107 dB

Launch, pricing, and availability

The SMSL R100 is now available internationally for US$289 from the Shenzhenaudio store on AliExpress.