Short answer
Both are dongles, $269 against $259.
The Cayin RU7 reaches 100 dB on 563 of the 567 models here, the Shanling UA5 on 562.
| Specification | Cayin RU7 | Shanling UA5 |
|---|---|---|
| Power into 32Ω | 160 mW | 137 mW |
| Power into 150Ω | 34 mW | 29 mW |
| Power into 300Ω | 17 mW | 15 mW |
| Power into 600Ω | 8.5 mW | 7.3 mW |
| Output impedance | not published | 0.8 Ω |
| Output noise | not published | 3.5 µV unverified |
| Price | $269 | $259 |
| Headphones it reaches 100 dB on out of 567 | 563 | 562 |
Not published means the maker leaves it out, so that axis cannot be compared.
| Balanced | Cayin RU7 | Shanling UA5 |
|---|---|---|
| Socket | 4.4mm | 4.4mm |
| Power into 32Ω | 400 mW | 211 mW |
| Power into 300Ω | 43 mW derived | 22 mW derived |
| Output impedance | not published | 1.6 Ω |
| Output noise | not published | not published |
| Headphones it reaches 100 dB on out of 567 | 565 | 564 |
Through the balanced sockets the Cayin RU7 reaches 100 dB on 565 of the 567 models here and the Shanling UA5 on 564. Derived figures are worked out from the loads the maker did publish.
| Load | Cayin RU7 | Shanling UA5 |
|---|---|---|
| 32 Ω | Published | Published |
| 150 Ω | Derived | Derived |
| 300 Ω | Derived | Derived |
| 600 Ω | Derived | Derived |
Both makers publish a power rating. Cayin RU7 publishes at 32 Ω; Shanling UA5 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.
1 headphone reaches 100 dB on the Cayin RU7 but not on the Shanling UA5 — Moondrop COSMO.
562 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 Sennheiser HD 600: Cayin RU7 has +4 dB of headroom there against +3 dB. 1 dB is about 1.2 times the power, which matters for peaks rather than for how loud the music sits.
The hiss columns are empty for Cayin RU7 and Shanling UA5 because neither maker publishes no output noise figure.
| Headphone | Impedance | Needs | Cayin RU7 headroom | Shanling UA5 headroom | Cayin RU7 hiss | Shanling UA5 hiss |
|---|---|---|---|---|---|---|
| Shure SE846 | 9 Ω | 0.04 mW | +31 dB | +30 dB | not published | not published |
| Campfire Audio Andromeda 2020 | 9 Ω | 4.0 mW | +11 dB | +10 dB | not published | not published |
| Audeze LCD-2 Classic | 70 Ω | 0.79 mW | +20 dB | +19 dB | not published | not published |
| Beyerdynamic DT 1990 Pro (250Ω) | 250 Ω | 0.63 mW | +15 dB | +14 dB | not published | not published |
| HiFiMAN HE400se | 25 Ω | 7.9 mW | +12 dB | +11 dB | not published | not published |
| Audio-Technica ATH-R70X | 470 Ω | 1.6 mW | +8 dB | +8 dB | not published | not published |
| Sennheiser HD 600 | 300 Ω | 6.6 mW | +4 dB | +3 dB | not published | not published |
| HiFiMAN Susvara | 60 Ω | 50 mW | +2 dB | +2 dB | not published | not published |
The Cayin RU7 costs $10 more than the Shanling UA5. Out of the 567 models here, that difference buys 1 more model 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: Cayin RU7 and Shanling UA5.