Sound performances
For this review, I paired the SMSL HO100 with various DAC, from the DO100 to the HiFiman EF400, and of course, the DO200. For headphones, I chose my old Audeze LCD-X, the FiiO FD7, and the lovely BeyerDynamic DT700 Pro-X
Overall signature
So, is the SMSL HO100 another chi-fi success? Seems like it!
Like the DO100, the HO100 is one of the most impressive devices I tried this year, in terms of quality/price ratio: powerful output, high current drive, linear signature, and, to top of all that, superb dynamic range. It’s utterly impressive and paired with my Sennheiser HD-800S, the small amp easily matched the HiFiman or my own Cayin iHA-6 on this aspect.
Power-wise, the HO100 is a tad less powerful than the HO200, but that doesn’t mean weak by any means – I don’t know who will ever need the high-gain setting! Whether it is the Audeze, the Sennheiser, or my Beyerdynamic, none of those headphones was a real treat to the SMSL. Fed by DO100, the SMSL HO100 will easily drive anything you want. It’s kinda like the Burson effect but with more depth and a narrower soundstage.
In pure, Dx00 tradition, the amp displays a perfectly linear signature. If you’re seeking warm voices or mellow highs, this won’t be the case here, and the SMSL HO100 was clearly designed to match the DO100. It’s transparent from top to bottom and reacts pretty well to DSP tuning, which means that you could perfectly use it to enjoy 3D effects with Tidal, Apple Music, or Qobuz new Atmos tracks.
To my surprise, I found the soundstage less narrow than the one heard on the HO200. Not by a big margin, but if you found the bigger brother too frontal, the SMSL H100 could match your taste. That said, the HO200 keeps the upper hand on transients and decay: the small amp is closer to the HiFiman EF400 in this aspect, even when paired with the DO200.
Paired with the Beyer, it’s a powerhouse. For my usual techno tracklist, the result was heavenly, with deafening bass, sharp mids, and magnificent layering. On tracks like Rave the planet from A*S*Y*S, the duo is simply terrific, and I would 100% advise this setup for any techno-lover, on the cheap. Yes, the dynamic is lower than the HO200, but the wider soundstage easily compensates for that. For example, in Infected Mushroom Return to the Sauce, there’s a lot of pan effect, moving back and forth plus ultra-saturated chords. None of that gave the small amp any difficulty and if the sound isn’t “natural”, it surpassed all of my expectations.
If you want to scale up, you can switch the DO100 for the DO200, something I did. What do you get? Better detail retrieval, softer mids, and better dynamic range. Everything seems effortless and side by side with my Cayin iHA-6, the SMSL didn’t fall short, even if the Cayin took the upper hand on some aspects. However, like the HO200, connected in balanced mode, the detail retrieval capability remained superior and in the long run, the amp seemed more natural, organic, and pleasing. At least to my ears.
Last, but not least, as promised there is absolutely NO noise. On paper, the HO200 is even quieter than the SMSL HO100 we review today (1.3uV vs 1.0uV) but in practice, it’s simply inaudible. Whatever the headphone, as long as your source is able to feed a proper signal, the amp was able to output a noiseless message. Once again, when I plugged my Audeze LCD-X, with just 30%, the sound pressure was already enough to fill 90% of my need. Above 50%, it gets CRAZY loud, so you should definitely stick to big cans like Audeze, Beyer, or Sennheiser. Lovely in every way.
For IEMs, the low-gain settings came quite handy, and I never encountered any channel imbalance even at a very low volume. Going balanced with the XLR input didn’t make a difference here, but the soundstage was definitely better within balanced, compared to the classic RCA input.
A perfect addition to SMSL line-up, at an entry-level price!
Tonality
The sound signature is absolutely linear, but each frequency range got its own flaws and qualities. A quick overview.
Bass: deep, fast, accurate. The HO100 managed to reach deep notes with ease on my LCD-X and, paired with the DO100, the duo gave me 70% of the HO200+DO200 performances. Clearly, in this price range, there’s nothing as accurate and “flawless” as this amp. SMSL didn’t put a bass-boost setting, for good reason, and I think this amp would be stellar with a Chord DAC.
Test track : Wurlitzer – Leifur James
Mids: flat and clean. Superb dynamic range combined with a powerful reserve makes for an exquisite medium. As expected, it’s absolutely grain-less/flawless, and compared to my usual amps voices are a bit less natural, but a bit more precise. That said, it’s still wondrous and fed with a premium DAC, I’m sure you would be able to rival any similarly priced combo with ease.
Test track : It takes a lot to know a man – Damien Rice
Highs: straight and technical. If everything seems flat to my ears, some might find the SMSL HO100 a bit too conservative, or even lacking in this regard. In fact, the amp will never pierce your ears, no matter the pairing. Compared to the bigger model, the small amp surprised me with a wider soundstage, while keeping excellent control throughout the whole spectrum.
Good test track : Ignorance – Rui Reis Maia
Conclusion
Tiny but mighty, the SMSL HO100 is a real killer for the price. For less than $150 US Dollars, it’s simply one of the best desktop AMP you could get at the moment, and one of the most powerful.
Sound quality is outstanding, build quality is lofty, power is bottomless, and the conception design makes it the perfect desk companion, whether if paired with the SMSL DO100, another DAC, or even a DAP. Pair it with a clean DAC to enjoy the device at its fullest and get a Y-split power cable to make a desktop duo, powered by a sole cable: the perfect duo.
A top choice for anyone who seeks a great amp, but doesn’t want to break the bank.
