SMSL D100 Review — Don't Let the Size Fool You

 

General/Packaging/Build

SMSL needs no introduction at this point, I've gone through a fair number of their dac/amps over the past year or so, from the SU-1 DAC to the M300SE, and they've been pretty consistent in delivering good value gear. The D100 is their latest ultra-compact desktop DAC and headphone amp combo, and this time they've gone smaller instead of bigger, packing an ESS ES9081 chip and a fully balanced headphone amp into a chassis roughly the size of your palm. Packaging is simple, unit arrives well protected, nothing fancy but does the job.

Build quality is solid as expected from SMSL, CNC-machined aluminium chassis, gold plated connectors, and a 1.66 inch fully laminated glass display up front that actually looks nicer in person than in photos. The 6.35mm and 4.4mm headphone outs sit on the front panel, dual USB-C ports round the back, one for data and one dedicated for auxiliary power when running off a phone, a nice touch to prevent battery drain on your source device.

Specifications

• Input USB / Optical / Coaxial

• Output 6.35mm Headphone / 4.4mm Balanced Headphone / RCA

• Line Output Level 2Vrms

• Output Power 32Ω 400mW2, 150Ω 105mW2, 300Ω 50mW*2

• THD+N Line Out: 0.00035% / SE Headphone Out: 0.00055% / Balanced Headphone Out: 0.00062%

• Dynamic Range Line Out: 121dB / SE Headphone Out: 116dB / Balanced Headphone Out: 116dB

• SNR Line Out: 129dB / SE Headphone Out: 116dB / Balanced Headphone Out: 117dB

• USB Transmission Asynchronous (USB 2.0)

• OS Compatibility Windows, Mac OS, Linux

• MQA Decoder USB / Optical / Coaxial

• Bit Depth USB PCM 16-32bit, DSD/DoP 1bit; OPT/COX PCM 16-24bit, DoP 1bit

• Sampling Rate USB PCM 44.1~768kHz, DSD 64~512, DoP 64~256; Optical/Coaxial PCM 44.1~192kHz, DoP 64

• Power Consumption 5W (Active) / 1.6W (Standby)

• Dimensions 12712732mm (WDH)

• Weight 338g / 0.745lbs

Gears used for this review

• iPhone 15

• Macbook Air M2

• SMSL D100

• Fiio K11

• 7Hz Legato

• Sennheiser HD660S

• Hifiman Sundara

Foreword

My review is solely based on what I hear via my equipment and I never consider my reviews to be objective in any way rather a subjective approach. Do take into consideration that everyone’s ear anatomy is not the same, so the psychoacoustics perception might be different as well, but i believe it will not stray too far

Driving Power

• Driving power is definitely sufficient for IEMs and efficient headphones, i have tried with Hifiman’s Sundara, while it doesn’t sound bad, but there’s certainly room for improvement as well

Features

• Low power consumption, does not need an external power supply, it can be powered solely by my Macbook Air M2’s USB port, even straight from my iPhone 15 via USB C, not an issue as well, there’s an auxiliary power input to maximize the power output, that’s a very welcoming feature in my opinion, i personally use the auxiliar power input when i’m using it with headphone

• As a Tidal user myself, full MQA decoding is definitely a welcoming feature for me

Sound Impression

Tonality wise, the D100 comes across as neutral with a very slight hint of warmth, nothing overtly coloured to my ears. It's not the most exciting sounding dac/amp out there, but it doesn't need to be, it lays down a clean, accurate foundation and lets the gear plugged into it do the talking. After about 30-40 hours on my burn-in rig, the treble smoothed out slightly and the overall presentation felt a touch more settled compared to out of the box. 

Listening Impression with the following gears

Sennheiser HD660S

• Bass is punchy and tight, mid bass especially

• Sub bass has slightly better extension, although still lacking due to it being an open back

• Mids has a bit more body 

• Slightly bigger soundstage

• Male vocal has slightly thicker texture and sounds fuller

• Female vocal is full sounding as well

• Not so much changes in terms of detail retrieval

• Overall, a very good synergy pairing the HD660s with D100

7Hz Legato

• Legato is a bassy and warm IEM, aimed at delivering analog-ish speaker sound

• The mids are slightly recessed, but when paired with D100, the mids doesn’t sound that recessed anymore and it sounded a little bit more forward, both male and female vocal also have better texture and body to it

• Bass on the other hand sounds a little tame when paired with D100, the sub bass doesn’t rumble that much, but mid bass is still punchy, a very refreshing experience if you ask me, still very fun sounding

• Not much changes on the detail retrieval as well

• Soundstage is slightly better in terms of better height,depth and width perception

• Legato is not hard to drive, but D100 definitely have more than enough power to push it hard as Legato scales really well with power and source

Hifiman Sundara on 4.4

• Sundara is a Planar headphone from Hifiman that requires quite a bit of power in order to perform at its best, D100 does have the capability to drive it to optimum performance with a 4VRMS voltage swing on balanced output

• Sundara on its own is quite neutral sounding with a slight hint of brightness in terms of tonality, pairing it with the D100 seems to be a good choice where the overall presentation has a bit more body to it

• The low end is slightly elevated due to the added warmth, treble is smoother yet it doesn’t compromise in terms of resolution, not to mention the soundstage is also slightly bigger

Comparison (Fiio K11)

• Build wise, the D100 is noticeably more compact than the K11, and personally I prefer the smaller footprint on a crowded desk. K11 does have the edge in input options with its gain switch and slightly more robust chassis, but the D100's glass display panel does look and feel more premium to my eyes

• In terms of sound, K11 leans towards that clean, uncoloured house sound I've mentioned before, quite neutral and a little less musical to my ears. The D100 sits in a similar neutral camp but carries a slight tinge of warmth that makes it a touch easier to listen to over long sessions.

• Bass on the K11 is a bit more elevated and punchy, especially on the sub bass, whereas the D100 is more restrained and controlled, doesn't bleed into the mids at all on either unit, both do well here.

• Soundstage is fairly close between the two, K11 maybe has a very slight edge in width, but it's close enough that I wouldn't call it a deciding factor

• Where the K11 really pulls ahead is driving power, up to 1.4W on balanced out compared to the D100's 400mW, so if you're running power hungry planars like the Sundara regularly, K11 will run circle around the D100 in terms of headroom and dynamics. But if MQA across all inputs and a smaller desktop footprint matter more to you than raw power, the D100 makes a strong case for itself. For my own use case, since I mostly pair mine with easier to drive IEMs and the occasional HD660S session, I'd lean towards the D100, but anyone running power hungry planars daily should go for the K11 instead

Final Thoughts

The D100 isn't trying to be the most powerful or the most feature packed dac/amp on the market, and it doesn't need to be. What it does, it does everything alright, clean neutral sound with a slight touch of warmth, full MQA decoding across all inputs, and a build quality that punches above its size. For anyone looking for a compact desktop solution to pair with easier to drive IEMs and headphones, this is an easy one to recommend. 

*A big thanks to SMSL for sending this over for the purpose of this review. I thank them for their support and opportunity

Head over to their official webstore if you are interested in getting one:

SMSL D100 - Non affiliated