SMSL has launched the R100, a desktop R2R DAC built around a pair of Analog Devices AD1861-J chips and a parametric EQ that is set up entirely from a web browser. Following FiiO’s K11 R2R and K13 R2R into the budget end of the R2R market, the SMSL R100 is priced at $289 and aims to bridge classic analog warmth with modern digital performance without requiring drivers or a dedicated app.
Two Classic Chips, Hand-Matched at the Factory
At the heart of the SMSL R100 sit two AD1861-J chips from Analog Devices, one per channel. Unlike DAC designs that build an R2R ladder from discrete resistors, the AD1861 is a monolithic chip with the ladder built in, so SMSL’s job is tuning the surrounding circuitry rather than the ladder itself. Each SMSL R100 unit is adjusted by hand at the factory so the two channels match, and a patented de-glitch circuit is designed to clean up the small errors an R2R ladder produces every time it switches between values. SMSL also includes a self-developed low-jitter clock algorithm intended to keep timing errors in check.
Bridging an 18-Bit Chip to Modern Formats
The SMSL R100 accepts USB audio up to 32-bit/768kHz PCM and DSD512, with coaxial and TOSLINK inputs topping out at 24-bit/192kHz PCM or DSD64 over DoP. Because the AD1861 is natively an 18-bit chip, SMSL places a 16x oversampling FIR filter ahead of the ladder chips to bridge the gap between those incoming formats and what the converter itself can resolve, with DSD signals converted before they reach the chips. Analogue outputs are balanced XLR at 3.5V and single-ended RCA at 1.75V, enough to drive an integrated amplifier or a pair of active loudspeakers directly. SMSL’s own measurements on an Audio Precision APx555 put THD+N at around 0.0025% from the balanced output. There is no headphone output and no volume control on the SMSL R100 — it is a DAC and nothing else.
A Parametric EQ You Set From a Browser
Alongside its R2R architecture, the SMSL R100 includes a driver-free, Web-based parametric EQ, configured entirely through a browser rather than a dedicated app. The parametric EQ lets a listener pick a frequency, set how wide a slice of the audio band to affect, and then cut or boost it — useful for taming a bass-heavy room or softening a bright pair of speakers or headphones. Filters save to one of two onboard memory slots, EQ1 or EQ2, with the SMSL R100 able to switch between those settings and a bypass mode called Direct.
CNC-Machined Chassis With Viewing Windows
The SMSL R100’s chassis is CNC-machined from aluminium, with two clear windows cut into the lid so the circuit board underneath stays visible during use. Silver is the only finish SMSL has listed so far for the R100.
Pricing and availability
The SMSL R100 is available now in the United States for $289; European pricing had not been announced at the time of writing. Full details are listed on SMSL’s official product page.
Key specifications
- Model: SMSL R100 desktop R2R DAC
- DAC chips: 2x Analog Devices AD1861-J (18-bit R2R ladder), hand-matched per unit
- Error correction: patented de-glitch circuit; self-developed low-jitter clock algorithm
- Oversampling: 16x oversampling FIR filter ahead of the DAC chips
- USB input: PCM up to 32-bit/768kHz, DSD up to DSD512
- Coaxial / TOSLINK input: PCM up to 24-bit/192kHz, DSD64 via DoP
- Analogue outputs: balanced XLR (3.5V), single-ended RCA (1.75V)
- Distortion: approx. 0.0025% THD+N (balanced, per SMSL’s APx555 measurements)
- EQ: driver-free Web-based parametric EQ, EQ1/EQ2 memory slots plus Direct bypass
- Chassis: CNC-machined aluminium with viewing windows
- Finish: Silver
- Headphone output / volume control: none
- Price: $289, available now in the US; European pricing TBA
