SMSL DO100 PRO Review: Feature-Packed DAC at $200

DACs play a critical role in delivering high-quality sound in any audio system that isn't purely analog. Digital-to-analog converters bridge the gap between the digital world of your music files and the analog world of sound waves our ears perceive. By converting digital data into analog signals, DACs directly influence the overall quality and character of the audio you experience.

Today we'll explore the SMSL DO100 PRO, a new option in the lower-mid-range price segment.

Build: Aluminum, with All the I/O You Need#

Is it built like a tank? No, but you wouldn't expect it to be for a bit over $200. Is it constructed poorly then? Nope, not that either.

Pick it up and you might be surprised. On one hand, it feels quite lightweight despite clocking in at nearly 1.5 kg (over 3 pounds). On the other hand, it features a full aluminum body - not the thickest one, but it's miles ahead of being made of plastic.

The bottom is supported by 4 tall rubber feet, which can be upgraded if needed, as they're held down by screws. They do a decent job - the unit doesn't slide very easily on the desk.

The top has a Hi-Res AudioA marketing certification (JAS / Hi-Res Music) for audio with sample rates ≥ 96kHz and bit depths ≥ 24-bit. The audible benefit over 16-bit/44.1kHz is debated; the legitimate benefit is reduced quantization error in the mixing chain. Wireless sticker, which is a nice addition, but it doesn't mean anything useful for the actual audio quality as far as I'm aware.

The DO100 PRO features a front screen that can display lots of useful information, like the current sampling rate, the input you're using, the high-frequency digital filterAn algorithm applied before DAC conversion that manages the transition from audio band to alias zone; choices include brick-wall, minimum-phase, and apodizing designs., brightness, and the DPLL value (more on which later). A retro-style knob located on the right side is plastic, with some wobble - but that's not a very big issue, as it's fully digitally stepped with a distinct tactile feel. It lets you go through all the options and set them up how you want them.

On the back, you'll find all the I/O: an AC input with a power switch, USB-C for digital connections, a Bluetooth antenna port for wireless audio streaming, HDMI ARC, Optical ToslinkSay: TOSS-link /ˈtɒs.lɪŋk/An optical S/PDIF digital audio interface using a plastic fibre and a red LED, common on TVs, soundbars, and consumer DACs. Limited to 24-bit/96kHz stereo PCM in practice; longer runs need glass fibre for stability., and Coaxial. For the analog outputs, there are single-endedAn amplifier configuration using one output device for the complete audio waveform; produces even-order harmonic distortion considered "euphonic" by many. RCA and balancedA signal transmission method using two opposite-polarity signal lines plus a ground; noise induced on both lines is cancelled at the differential input. XLRA professional locking audio connector with three pins: ground, positive signal, and negative signal; the standard for balanced studio connections. outputs. It's worth noting that the DO100 PRO is a balanced DACDigital-to-Analog Converter, a device that translates binary audio data into an analog electrical signal that can be amplified and heard. internally, and I noticed a slight improvement in sound quality when utilizing the balanced XLR outputs.

Features: ESS Chips, DSD512, DPLL Control#

Now, onto the features - there's a lot. At its core sit two new-generation high-end ESS DAC chips, working together with six high-end OPA1612 dual op-amps, fed by a brand-new third-generation XMOS chip that supports up to PCMPulse-Code Modulation, the standard digital audio format, encoding amplitude as binary integers at fixed time intervals (e.g., 16-bit/44.1kHz for CD). 32-bit/768kHz and DSD512. It'll happily decode DSDDirect Stream Digital, a 1-bit, high-sample-rate audio format used on SACD, encoding audio through rapid single-bit switching rather than multi-bit PCM words. as well as DoP64, and it even handles the most controversial formats on Earth - MQAMaster Quality Authenticated, a proprietary lossy compression format claiming to preserve master-quality information in a smaller file. Critics argue it adds distortion and serves rights-holder DRM more than fidelity; Tidal removed MQA from its catalogue in 2024. and MQA-CD - which is nice to have whether or not you ever end up using them. On the connectivity and convenience side you get two selectable USB modes, 1.1 and 2.0, depending on the device you're hooking up to, plus a Japan Audio Association Hi-Res certification, a choice of multiple digital filters, and a lightweight remote that does its job just fine.

The ESS chips feature a DPLL value control, a special function typically not exposed to the end user. This function allows you to select a value between 1 and 9, based on the clock jitterTiming irregularities in the digital audio clock that cause correlated noise sidebands, audible as a subtle smearing or loss of focus. and accuracy. If the clock stability is high, you can decrease this value to improve system performance and achieve slightly superior sound quality. On the other hand, increasing the value would be beneficial if you encounter a significant amount of clock jitter leading to audio artifacts such as digital noise and pops.

The maximum supported PCM sampling rate is 768kHz at a 32-bit dynamic rangeThe decibel span between a system's maximum undistorted output and its noise floor; 16-bit audio has ~96dB, 24-bit has ~144dB of theoretical range., which is close to the highest possible PCM resolutionA system's ability to retrieve and reproduce fine detail in the recording; high resolution reveals micro-dynamics, spatial cues, and timbral nuance. you can achieve. This leaves you with a lot of room for upsamplingConverting audio from its native sample rate to a higher rate, either in the DAC chip or in software, using a mathematical interpolation algorithm. using software like HQPlayer or PGGB.

That's a lot of functions for a DAC in this price category. But how does it sound?

Sound: Solid, Slightly Analytical, a Touch Soft#

First of all, it's solid - really solid. There are no sonic issues with it that could be bothersome. It leans slightly to an analyticalA presentation that prioritizes detail retrieval and accuracy over harmonic richness; analytical systems reveal flaws clearly but may lack emotional engagement. side of tonality, likely due to the ESS DAC chips used inside. However, it's not sharp or unpleasant, and if you don't like the ever-so-slightly enhanced top-end presentation, you can use a faster and more aggressive filter.

For systems that are neutral or slightly lacking in treble detail, the DO100 PRO is unlikely to push things into excessively bright territory. In these cases, it could potentially enhance clarity, detail, and definition without introducing harshness. Besides that, the tonal presentation is mostly neutral, without any added warmthA subjective description of elevated bass and lower-midrange energy giving a sense of fullness; can be a tonally accurate or an artificial coloration. or bassSay: BAYSS /beɪs/The low-frequency foundation of audio, roughly 20-250 Hz - felt as much as heard, carrying a track's weight, warmth, and impact. (Said "BAYSS", like the guitar, not the fish.) energy.

Resolution-wise, it's a bit above average. I'd say it can resolve details fairly well on a macro scale, as you'd expect for a modern DAC, and it does just fine on a micro scale. Unless your expectations are sky-high, you won't be disappointed.

The soundstageThe perceived three-dimensional acoustic space in a stereo recording, width beyond the speakers, depth front-to-back, and sometimes height information. presentation isn't huge, but it doesn't collapse in any of the dimensions. Width is there, depth is there, and height is also there - but to a lesser extent. Of course, it does not sound HUGE like top-of-the-line DACs that cost multiple times more, but it is definitely not collapsing the sound and making it tiny.

Let's talk dynamics. It's not room-shaking, not at all. But what I feel it's doing is being true to source, and capable enough for most kinds of music and gear. Generally, I felt a slight sense of softness - not particularly a lack of dynamics, but softness. That didn't bother me much, and it's already miles ahead of SMSL's lower-end products.

So in terms of the DO100 PRO, I think it's priced well. It doesn't break any world records, but it's just a good-sounding DAC for this price, which can be a decent step up from some cheaper units. It lets you have fun with lots of options, adjust them to your liking, and explore different flavors of digital audio.