Short answer
Both are desktop amplifiers, $149 against $160.
On raw power they are level: each reaches 100 dB on 567 of the 567 non-electrostatic models here.
| Specification | Schiit Vali 2+ | SMSL HO100 |
|---|---|---|
| Power into 32Ω | 1.5 W | 1.5 W |
| Power into 150Ω | 496 mW | 354 mW |
| Power into 300Ω | 400 mW | 200 mW |
| Power into 600Ω | 200 mW | 100 mW |
| Output impedance | 1.8 Ω | <0.1 Ω |
| Output noise | 25 µV unverified | 1.3 µV |
| Price | $149 | $160 |
| Headphones it reaches 100 dB on out of 567 | 567 | 567 |
| Load | Schiit Vali 2+ | SMSL HO100 |
|---|---|---|
| 32 Ω | Published | Published |
| 150 Ω | Derived | Derived |
| 300 Ω | Published | Published |
| 600 Ω | Published | Published |
Both makers publish a power rating. Schiit Vali 2+ publishes at 32 Ω, at 300 Ω and at 600 Ω; SMSL HO100 at 32 Ω, at 300 Ω and at 600 Ω. The other rows are worked out from those.
The two publish at the same loads, which is the one case where the rows of this table can be read straight across.
On power they are interchangeable across this whole database: there is no headphone here that one reaches 100 dB on and the other does not.
72 headphones are left alone by the SMSL HO100 under the one-eighth rule but coloured by the Schiit Vali 2+ (64 Audio Aspire 1, 64 Audio Fourte, 64 Audio Nio, 69 more).
567 of the 567 models here reach 100 dB on both.
Headroom is at a 100 dB SPL peak.
The widest gap on the list is the Shure SE846: SMSL HO100 has +46 dB of headroom there against +40 dB. 6 dB is about 4 times the power, which matters for peaks rather than for how loud the music sits.
The hiss columns are empty for Schiit Vali 2+ because that maker publishes no output noise figure.
| Headphone | Impedance | Needs | Schiit Vali 2+ headroom | SMSL HO100 headroom | Schiit Vali 2+ hiss | SMSL HO100 hiss |
|---|---|---|---|---|---|---|
| Shure SE846 | 9 Ω | 0.04 mW | +40 dB damping | +46 dB | not published | 17 dB |
| Campfire Audio Andromeda 2020 | 9 Ω | 4.0 mW | +20 dB damping | +26 dB | not published | -3 dB |
| Audeze LCD-2 Classic | 70 Ω | 0.79 mW | +30 dB | +30 dB | not published | -5 dB |
| Beyerdynamic DT 1990 Pro (250Ω) | 250 Ω | 0.63 mW | +28 dB | +26 dB | not published | -10 dB |
| HiFiMAN HE400se | 25 Ω | 7.9 mW | +22 dB | +24 dB | not published | -11 dB |
| Audio-Technica ATH-R70X | 470 Ω | 1.6 mW | +22 dB | +19 dB | not published | -16 dB |
| Sennheiser HD 600 | 300 Ω | 6.6 mW | +18 dB | +15 dB | not published | -21 dB |
| HiFiMAN Susvara | 60 Ω | 50 mW | +12 dB | +12 dB | not published | -23 dB |
The SMSL HO100 costs $11 more than the Schiit Vali 2+. Out of the 567 models here, that difference buys 72 more models left alone under the one-eighth rule.
Nothing runs the other way: there is no axis here on which the cheaper of the two does better.
Only published figures count here; blank axes are counted separately.
Each in full: Schiit Vali 2+ and SMSL HO100.