Short answer
Both are audio interfaces, $199 against $299.
The Universal Audio Volt 276 reaches 100 dB on 558 of the 567 models here, the Tascam US-2x2HR on 541.
| Specification | Tascam US-2x2HR | Universal Audio Volt 276 |
|---|---|---|
| Power into 32Ω | 18 mW | 84 mW |
| Power into 150Ω | 17 mW | 28 mW |
| Power into 300Ω | 12 mW | 22 mW |
| Power into 600Ω | 7.3 mW | 12 mW |
| Output impedance | 66 Ω | not published |
| Output noise | not published | not published |
| Price | $199 | $299 |
| Headphones it reaches 100 dB on out of 567 | 541 | 558 |
Not published means the maker leaves it out, so that axis cannot be compared.
| Load | Tascam US-2x2HR | Universal Audio Volt 276 |
|---|---|---|
| 32 Ω | Published | Published |
| 150 Ω | Derived | Derived |
| 300 Ω | Derived | Published |
| 600 Ω | Derived | Published |
Both makers publish a power rating. Tascam US-2x2HR publishes at 32 Ω; Universal Audio Volt 276 at 32 Ω, at 300 Ω and at 600 Ω. The other rows are worked out from those.
So the two columns are not equally firm row by row: at 300 Ω and at 600 Ω only the Universal Audio Volt 276 figure is the maker’s own. On those rows the derived number is the one to doubt first.
17 headphones reach 100 dB on the Universal Audio Volt 276 but not on the Tascam US-2x2HR — Abyss AB-1266 Phi TC, Audeze LCD-5, Dan Clark Audio AEON 2 Closed, 14 more.
541 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 HiFiMAN HE400se: Universal Audio Volt 276 has +9 dB of headroom there against +2 dB. 7 dB is about 4.7 times the power, which matters for peaks rather than for how loud the music sits.
The hiss columns are empty for Tascam US-2x2HR and Universal Audio Volt 276 because neither maker publishes no output noise figure.
| Headphone | Impedance | Needs | Tascam US-2x2HR headroom | Universal Audio Volt 276 headroom | Tascam US-2x2HR hiss | Universal Audio Volt 276 hiss |
|---|---|---|---|---|---|---|
| Shure SE846 | 9 Ω | 0.04 mW | +21 dB damping | +28 dB | not published | not published |
| Campfire Audio Andromeda 2020 | 9 Ω | 4.0 mW | +1 dB damping | +8 dB | not published | not published |
| Audeze LCD-2 Classic | 70 Ω | 0.79 mW | +13 dB damping | +18 dB | not published | not published |
| Beyerdynamic DT 1990 Pro (250Ω) | 250 Ω | 0.63 mW | +13 dB damping | +16 dB | not published | not published |
| HiFiMAN HE400se | 25 Ω | 7.9 mW | +2 dB damping | +9 dB | not published | not published |
| Audio-Technica ATH-R70X | 470 Ω | 1.6 mW | +7 dB damping | +10 dB | not published | not published |
| Sennheiser HD 600 | 300 Ω | 6.6 mW | +3 dB damping | +5 dB | not published | not published |
| HiFiMAN Susvara | 60 Ω | 50 mW | -5 dB damping | +0 dB | not published | not published |
The Universal Audio Volt 276 costs $100 more than the Tascam US-2x2HR. Out of the 567 models here, that difference buys 17 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: Tascam US-2x2HR and Universal Audio Volt 276.