Short answer
Both are audio interfaces, $432 against $589.
The Universal Audio Volt 476P reaches 100 dB on 558 of the 567 models here, the Roland Rubix44 on 542.
| Specification | Roland Rubix44 | Universal Audio Volt 476P |
|---|---|---|
| Power into 32Ω | 19 mW | 84 mW |
| Power into 150Ω | 15 mW | 28 mW |
| Power into 300Ω | 9.4 mW | 22 mW |
| Power into 600Ω | 5.4 mW | 12 mW |
| Output impedance | 47 Ω | not published |
| Output noise | not published | not published |
| Price | $432 | $589 |
| Headphones it reaches 100 dB on out of 567 | 542 | 558 |
Not published means the maker leaves it out, so that axis cannot be compared.
| Load | Roland Rubix44 | Universal Audio Volt 476P |
|---|---|---|
| 32 Ω | Derived | Published |
| 150 Ω | Derived | Derived |
| 300 Ω | Derived | Published |
| 600 Ω | Derived | Published |
Only one of these two columns starts from a power rating. Universal Audio Volt 476P publishes one at 32 Ω, at 300 Ω and at 600 Ω; Roland Rubix44 publishes none at any of these four loads, so its column is worked out from power it published at other loads. Both are arithmetic on a maker’s own figures rather than guesses, and the method used for the Roland Rubix44 understates rather than flatters — but at 32 Ω, at 300 Ω and at 600 Ω are the only loads here at which its maker can be held to a figure.
16 headphones reach 100 dB on the Universal Audio Volt 476P but not on the Roland Rubix44 — Audeze LCD-5, Dan Clark Audio AEON 2 Closed, Dan Clark Audio AEON 2 Noire, 13 more.
542 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: Universal Audio Volt 476P has +8 dB of headroom there against +1 dB. 6 dB is about 4.4 times the power, which matters for peaks rather than for how loud the music sits.
The hiss columns are empty for Roland Rubix44 and Universal Audio Volt 476P because neither maker publishes no output noise figure.
| Headphone | Impedance | Needs | Roland Rubix44 headroom | Universal Audio Volt 476P headroom | Roland Rubix44 hiss | Universal Audio Volt 476P 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 | +12 dB damping | +16 dB | not published | not published |
| HiFiMAN HE400se | 25 Ω | 7.9 mW | +3 dB damping | +9 dB | not published | not published |
| Audio-Technica ATH-R70X | 470 Ω | 1.6 mW | +6 dB | +10 dB | not published | not published |
| Sennheiser HD 600 | 300 Ω | 6.6 mW | +2 dB damping | +5 dB | not published | not published |
| HiFiMAN Susvara | 60 Ω | 50 mW | -4 dB damping | +0 dB | not published | not published |
The Universal Audio Volt 476P costs $157 more than the Roland Rubix44. Out of the 567 models here, that difference buys 16 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: Roland Rubix44 and Universal Audio Volt 476P.