SMSL sent me the SP200 to review. After the Drop THX AAA 789 I was curious to check it out.
THX AAA-based amps have a reputation for their excellent measurements and fantastic clarity, so with SMSL releasing a cheaper competitor to the Drop THX AAA 789, and Schiit having just updated their Asgard 3, it made for an interesting review experience.
The amp is quite small, significantly more so than either the Drop or Schiit amps, though larger than a Magni. Like the Asgard, it has a direct power in rather than using a wall-wart as the Drop amp does. However, feature wise it doesn’t have the auto-off, or lowest gain level, nor does it have a 3.5mm jack, meaning that IEM users will need an adaptor for the 6.5mm socket.
Like other THX amps, it has balanced and single-ended inputs (XLR and RCA respectively), but as the amp circuit itself is only single-ended internally, the balanced input will be converted to single-ended before amplification. That makes the RCA inputs the most ideal. For headphones, however, it has 4-pin XLR and 6.3mm sockets, though the former isn’t a balanced output.
Like other THX amps, it uses active negative feedback to reduce distortion, resulting in great measurements. However, this does not relate directly to the performance, as measurements are only taken using sweeps and tones, not actual music. It does have a lot of power, as the THX 888 circuit has 6 Watts of power output (at 16 Ohms) and 3W of power at 32 Ohms, more than enough to drive even very insensitive headphones like some HiFiMan models.
It is also very quiet with IEMs, only the very sensitive Andromedas bringing out hiss. However of the two gain settings available, the lower one doesn’t give much volume control range for IEMs, making it less than ideal, especially as the cheap volume pots used in these amps often have channel mismatch at the very start of their travel.
I tested the SP200 from a Schiit Bifrost 2 and Yggdrasil, as well as a Hugo 2 primarily. Headphone-wise I had a Drop Sennheiser HD6XX, HiFiMan Sundara and a variety of high-end headphones on hand such as the Focal Utopias and Meze Empyreans. As it is an inexpensive amp, I tended to focus on the experience with equally inexpensive headphones, with the high-end models used only to confirm performance differences.
I listened to a huge variety of music. While in the past I might focus on particular types of music, especially for headphones and IEMs, when it comes to electronics, I tend to focus on the overall results, using a particular track or two that most demonstrate the differences I heard.
First impressions of the SP200 were of the typical THX “sound” — clean, clear and lacking in any (obvious) colouration. I didn’t have any issue driving any headphones at all, with enough voltage swing for the HD6XX and enough power that I could even run Susvaras out of them. IEMs, as previously stated, didn’t have enough volume control range for it to be an ideal amp for them, even out of the 6.3mm socket. However, the SP200 never sounded strained driving headphones, and I found myself hearing clearly the way each DAC presents the music.
In general, while very clean and clear sounding, the SP200 did present something of a flatter soundstage that wasn’t as deep as other amps. This was most noticeable in comparisons with high-quality stereo recordings which was already quite familiar. Schiit Audio’s Asgard 3, for example, which I level-matched to within 0.1dB, didn’t have the same clean-and-clear sound, sounding warmer, but it did seem to present more depth to the music. As well, drum impacts seemed a bit flat from the SP200, where they has more body from the Asgard 3. The SP200 had the strength of sounding more clear on some tracks, especially in the treble, than the Asgard 3.
Level-matched as before, it was quite difficult to tell it apart from the Drop THX AAA 789. However, after some careful back-and forth listening, the Drop amp sounded deeper and also managed to bring out the subtle nuances of music better than the SP200. This was most noticeable with high-quality recordings. However, the Drop amp is a third more expensive, which is very significant in this price range. It should also be noted that I was using much more expensive high-end DACs, which really puts this review in perspective. With less expensive DACs, I’d be surprised if it were possible to notice the difference.
What the SP200 offers is both a technically and sonically great performance for the $289 that they are asking. For the average person buying to to use with a similarly priced DAC, or as a more powerful amp to use with a DAP, the SP200 offers a great degree of power and clarity that will appeal a great deal to people who consider measured performance important.