R2R DAC with web-based PEQ

The SMSL R100 is a desktop R2R DAC centered around two Analog Devices AD1861-J converter chips, with support for high-resolution PCM and DSD playback, web-based parametric EQ, dedicated digital filtering, and both balanced XLR and RCA analog outputs. Its CNC-machined aluminum chassis includes dual top viewing windows that reveal the internal circuitry, while USB, optical, and coaxial inputs provide flexible connectivity for desktop and hi-fi systems.

Dual AD1861-J R2R conversion

Two AD1861-J R2R DAC chips handle digital-to-analog conversion using a resistor-ladder architecture associated with a natural, relaxed tonal presentation. SMSL pairs the converters with a proprietary de-glitch circuit designed to reduce transient conversion errors, signal distortion, digital noise, and unwanted artifacts during processing.

High-resolution PCM and DSD support

The R100 supports PCM playback up to 32-bit/768kHz over USB, along with DSD rates up to 22.5792MHz. Optical and coaxial connections support PCM up to 24-bit/192kHz and DSD64 through DoP. A dedicated DSD conversion algorithm allows DSD source material to be processed through the R2R architecture.

Web-based parametric EQ

A browser-accessible PEQ system lets you adjust frequency response without installing dedicated software. Direct EQ, EQ1, and EQ2 provide three independent sound modes, with parameter storage for recalling saved tuning profiles.

Precision digital filtering

SMSL uses a self-developed high-precision SPDIF digital filter algorithm to manage incoming digital signals. The processing is designed to reduce clock-jitter effects and maintain stable digital transmission, supporting clearer separation and more consistent detail from optical and coaxial sources.

Balanced and RCA outputs

The rear panel provides balanced XLR and single-ended RCA outputs for connection to a range of amplifiers and powered audio systems. Rated output level is 3.5Vrms through XLR and 1.75Vrms through RCA, with a specified output impedance of 33 ohms.

Measured audio performance

SMSL lists THD+N at 0.003% and provides Audio Precision APx555 B measurement data showing balanced line-output THD+N of approximately 0.0025%. Rated balanced dynamic range and SNR are both 107dB, while RCA dynamic range and SNR are rated at 108dB.

Gold-plated signal connections

Gold-plated input and output connectors are used to help maintain stable electrical contact over time. The plating is intended to improve resistance to oxidation, corrosion, and wear while minimizing losses at the connection points.

CNC-machined aluminum chassis

The R100 chassis is produced with integrated CNC milling followed by grinding and polishing processes. Its rigid aluminum construction is designed to provide a stable enclosure for the internal audio circuitry while keeping the footprint compact enough for desktop systems and equipment racks.

Dual top viewing windows

Two transparent panels on the top of the chassis expose sections of the internal hardware layout. They provide a clear view of the component arrangement while giving the R100 a distinctive physical design centered on its internal engineering.

Broad computer compatibility

USB operation supports Windows 7, 8, 8.1, 10, and 11 with a driver. macOS 10.6 or later and Linux are supported without a dedicated driver, making the R100 suitable for a wide range of computer-based audio systems.

Product highlights

• Dual Analog Devices AD1861-J R2R DAC chips
  
• Proprietary de-glitch processing circuit
  
• PCM support up to 32-bit/768kHz over USB
  
• DSD support up to 22.5792MHz over USB
  
• DSD64 DoP support over optical and coaxial
  
• Web-based parametric EQ
  
• Direct EQ, EQ1, and EQ2 memory modes
  
• Self-developed high-precision SPDIF digital filtering
  
• Balanced XLR and RCA analog outputs
  
• Gold-plated input and output connectors
  
• CNC-machined aluminum chassis
  
• Dual transparent top viewing panels

Specs

• Inputs: USB, optical, coaxial
  
• Outputs: XLR, RCA
  
• XLR output level: 3.5Vrms
  
• RCA output level: 1.75Vrms
  
• THD+N: 0.003% (-90dB)
  
• Balanced measured THD+N: approximately 0.0025%
  
• XLR dynamic range: 107dB
  
• RCA dynamic range: 108dB
  
• XLR SNR: 107dB
  
• RCA SNR: 108dB
  
• Output impedance: 33 ohms
  USB bit depth: 1-bit DSD, 16 to 32-bit PCM
  
• Optical and coaxial bit depth: 1-bit DSD, 16 to 24-bit PCM
  
• USB PCM sampling rate: 44.1kHz to 768kHz
  
• USB DSD sampling rate: 2.8224MHz to 22.5792MHz
  
• USB DoP sampling rate: 2.8224MHz to 11.2896MHz
  
• Optical and coaxial PCM sampling rate: 44.1kHz to 192kHz
  
• Optical and coaxial DSD support: DSD64 DoP
  
• Windows compatibility: Windows 7, 8, 8.1, 10, and 11 — driver required
  
• Mac compatibility: macOS 10.6 or later — driverless
  
• Linux compatibility: Driverless
  
• Power consumption: 2.6W
  
• Standby power: less than 1W
  
• Dimensions: 6.69 x 1.57 x 5.35 in (170 x 39.8 x 136 mm) W x H x D
  
• Weight: 1.57 lb (712 g)
  
• AC input: 100–240V

What’s included

• SMSL R100 R2R DAC