In this video I review the S.M.S.L SP200, a THX-based headphone amp that uses THX’s flagship AAA 888 topology—the same basic topology you’ll see in amps like the Benchmark HPA4, but here it lands at an entry-level price. Huge thanks to APOS Audio for loaning me the SP200 (and the matching M200 DAC) so I could spend time with it again and finally get a proper review out. I go over pricing, power specs, and the practical stuff like inputs, gain, and how it fits into a balanced stack setup. On the hardware side, the SP200 is a small, solid all-metal unit with satisfying toggle switches (I actually prefer these over menu-driven controls). My main build complaint is the volume knob—it works fine, but it feels a bit cheap and too easy to turn. Functionally, the big story is gain: this amp has stupid gain and stupid power, especially over XLR, to the point where I basically never needed to go past ~12 o’clock and I found it pretty much unusable with IEMs unless I cut a lot of line volume at the DAC. Sound-wise, I compare it to the Schiit Magni 3+ (Magnus). The SP200 is very clean, dry, and analytical—classic “THX amp” vibes—while the Magni comes off warmer and more dynamic, especially in microdynamics. If you want a clean, analytical budget amp with balanced out and tons of power, the SP200 is a solid pick; if you want something more warm and engaging, I’d look at Magni 3+ or Asgard 3 instead.