Short answer
Both are desktop DAC/amps, $170 against $219.
The SMSL C200 reaches 100 dB on 567 of the 567 models here, the Loxjie A30 on 560.
| Specification | Loxjie A30 | SMSL C200 |
|---|---|---|
| Power into 32Ω | 100 mW | 1.3 W |
| Power into 150Ω | 21 mW | 277 mW |
| Power into 300Ω | 11 mW | 139 mW |
| Power into 600Ω | 5.3 mW | 69 mW |
| Output impedance | not published | not published |
| Output noise | not published | not published |
| Price | $170 | $219 |
| Headphones it reaches 100 dB on out of 567 | 560 | 567 |
Not published means the maker leaves it out, so that axis cannot be compared.
| Load | Loxjie A30 | SMSL C200 |
|---|---|---|
| 32 Ω | Published | Published |
| 150 Ω | Derived | Derived |
| 300 Ω | Derived | Derived |
| 600 Ω | Derived | Derived |
Both makers publish a power rating. Loxjie A30 publishes at 32 Ω; SMSL C200 at 32 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.
7 headphones reach 100 dB on the SMSL C200 but not on the Loxjie A30 — Moondrop COSMO, Moondrop PARA, Moondrop PARA 2, 4 more.
560 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 Campfire Audio Andromeda 2020: SMSL C200 has +26 dB of headroom there against +8 dB. 17 dB is about 52 times the power, which matters for peaks rather than for how loud the music sits.
The hiss columns are empty for Loxjie A30 and SMSL C200 because neither maker publishes no output noise figure.
| Headphone | Impedance | Needs | Loxjie A30 headroom | SMSL C200 headroom | Loxjie A30 hiss | SMSL C200 hiss |
|---|---|---|---|---|---|---|
| Shure SE846 | 9 Ω | 0.04 mW | +28 dB | +46 dB | not published | not published |
| Campfire Audio Andromeda 2020 | 9 Ω | 4.0 mW | +8 dB | +26 dB | not published | not published |
| Audeze LCD-2 Classic | 70 Ω | 0.79 mW | +18 dB | +29 dB | not published | not published |
| Beyerdynamic DT 1990 Pro (250Ω) | 250 Ω | 0.63 mW | +13 dB | +24 dB | not published | not published |
| HiFiMAN HE400se | 25 Ω | 7.9 mW | +10 dB | +23 dB | not published | not published |
| Audio-Technica ATH-R70X | 470 Ω | 1.6 mW | +6 dB | +17 dB | not published | not published |
| Sennheiser HD 600 | 300 Ω | 6.6 mW | +2 dB | +13 dB | not published | not published |
| HiFiMAN Susvara | 60 Ω | 50 mW | +0 dB | +11 dB | not published | not published |
The SMSL C200 costs $49 more than the Loxjie A30. Out of the 567 models here, that difference buys 7 more models driven to 100 dB.
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: Loxjie A30 and SMSL C200.