The Cayin RU7 is a USB dongle at $269. It delivers 160 mW into 32Ω and 17 mW into 300Ω, which ranks it 172 of 280 for raw power among the sources in this database.
Measured at 100 dB SPL it has comfortable headroom on 517 of the 567 dynamic and planar headphones catalogued here, enough but not generous on 40, only marginal on 6 and not enough power for 4. A 1-bit discrete resistor-ladder converter in a dongle, which is unusual at any size. Cayin publishes power at one load only.
The manufacturer publishes 160 mW into 32Ω. The rest of the table is worked out from those.
The balanced output is rated separately: 400 mW into 32Ω through the 4.4mm jack.
Derived rows hold output voltage steady, as an amplifier does (method).
Source: en.cayin.cn.
| Load | Power | Status | How it was arrived at |
|---|---|---|---|
| 32 Ω | 160 mW | Published | the manufacturer publishes this figure at this exact load |
| 150 Ω | 34 mW | Derived | beyond the published loads, holding output voltage constant — which understates rather than flatters |
| 300 Ω | 17 mW | Derived | beyond the published loads, holding output voltage constant — which understates rather than flatters |
| 600 Ω | 8.5 mW | Derived | beyond the published loads, holding output voltage constant — which understates rather than flatters |
Easiest to hardest to drive, with headroom at a 100 dB SPL peak.
| Headphone | Impedance | Sensitivity | Needs | Headroom | Verdict |
|---|---|---|---|---|---|
| Shure SE846 | 9 Ω | 114.0 dB/mW | 0.04 mW | +31 dB | Comfortable |
| 64 Audio U12t | 12.6 Ω | 108.0 dB/mW | 0.16 mW | +26 dB | Comfortable |
| Shure SE215 | 17 Ω | 107.0 dB/mW | 0.20 mW | +26 dB | Comfortable |
| Moondrop Aria | 32 Ω | 107.1 dB/mW | 0.19 mW | +29 dB | Comfortable |
| Audeze LCD-X 2021 | 20 Ω | 103.0 dB/mW | 0.50 mW | +23 dB | Comfortable |
| Truthear Hexa | 20.5 Ω | 103.1 dB/mW | 0.49 mW | +23 dB | Comfortable |
| Sennheiser IE 200 | 18 Ω | 101.6 dB/mW | 0.69 mW | +21 dB | Comfortable |
| Sony MDR-7506 | 63 Ω | 106.0 dB/mW | 0.25 mW | +25 dB | Comfortable |
| Meze 99 Classics | 32 Ω | 103.0 dB/mW | 0.50 mW | +25 dB | Comfortable |
| Focal Clear MG | 55 Ω | 104.0 dB/mW | 0.40 mW | +24 dB | Comfortable |
| Philips SHP9500 | 32 Ω | 101.0 dB | 0.79 mW | +23 dB | Comfortable |
| Focal Utopia | 80 Ω | 104.0 dB/mW | 0.40 mW | +22 dB | Comfortable |
| Meze Empyrean | 32 Ω | 100.0 dB | 1.0 mW | +22 dB | Comfortable |
| Campfire Audio Andromeda 2020 | 9 Ω | 94.0 dB | 4.0 mW | +11 dB | Comfortable |
| Etymotic ER2SE | 15 Ω | 96.0 dB/mW | 2.5 mW | +15 dB | Comfortable |
| AKG K371 | 32 Ω | 99.1 dB/mW | 1.2 mW | +21 dB | Comfortable |
| Audio-Technica ATH-M50X | 38 Ω | 99.0 dB/mW | 1.3 mW | +20 dB | Comfortable |
| Beyerdynamic DT 900 Pro X | 48 Ω | 100.0 dB/mW | 1.0 mW | +20 dB | Comfortable |
| Audeze LCD-2 Classic | 70 Ω | 101.0 dB/mW | 0.79 mW | +20 dB | Comfortable |
| Grado SR80x | 38 Ω | 98.0 dB/mW | 1.6 mW | +19 dB | Comfortable |
| Sennheiser HD 560S | 120 Ω | 100.8 dB/mW | 0.83 mW | +17 dB | Comfortable |
| HiFiMAN Edition XS | 18 Ω | 92.0 dB | 6.3 mW | +12 dB | Comfortable |
| HiFiMAN Arya Stealth | 32 Ω | 94.0 dB | 4.0 mW | +16 dB | Comfortable |
| Dan Clark Audio AEON 2 Closed | 13 Ω | 90.0 dB/mW | 10 mW | +8 dB | Enough |
| Audeze LCD-5 | 14 Ω | 90.0 dB/mW | 10 mW | +8 dB | Enough |
| Beyerdynamic DT 1990 Pro (250Ω) | 250 Ω | 102.0 dB/mW | 0.63 mW | +15 dB | Comfortable |
| HiFiMAN HE400se | 25 Ω | 91.0 dB | 7.9 mW | +12 dB | Comfortable |
| HiFiMAN Sundara | 32 Ω | 92.0 dB | 6.3 mW | +14 dB | Comfortable |
| Dan Clark Audio Stealth | 23 Ω | 90.0 dB/mW | 10 mW | +11 dB | Comfortable |
| Fostex T50RP MK3 | 50 Ω | 92.0 dB/mW | 6.3 mW | +12 dB | Comfortable |
| AKG K702 | 62 Ω | 92.9 dB/mW | 5.1 mW | +12 dB | Comfortable |
| ZMF Verite Closed | 300 Ω | 99.0 dB/mW | 1.3 mW | +11 dB | Comfortable |
| Sennheiser HD 650 | 300 Ω | 97.8 dB/mW | 1.7 mW | +10 dB | Comfortable |
| Sennheiser HD 800S | 300 Ω | 96.8 dB/mW | 2.1 mW | +9 dB | Enough |
| Beyerdynamic DT 770 Pro (250Ω) | 250 Ω | 96.0 dB | 2.5 mW | +9 dB | Enough |
| Audio-Technica ATH-R70X | 470 Ω | 98.0 dB/mW | 1.6 mW | +8 dB | Enough |
| ZMF Atrium | 300 Ω | 96.0 dB/mW | 2.5 mW | +8 dB | Enough |
| Abyss AB-1266 Phi TC | 50 Ω | 88.0 dB/mW | 16 mW | +8 dB | Enough |
| Sennheiser HD 600 | 300 Ω | 91.8 dB/mW | 6.6 mW | +4 dB | Enough |
| HiFiMAN Susvara | 60 Ω | 83.0 dB | 50 mW | +2 dB | Marginal |
The manufacturer does not publish an output noise figure for this source, so there is no hiss estimate here. If you have a measured figure, the hiss calculator takes it.
The manufacturer does not publish an output impedance for this source. Without it, nothing here can say how this source will behave with a multi-driver in-ear.
With a measured figure, the checker works out the consequence.
| Source | Type | Price | Into 300 Ω | Output impedance | Output noise |
|---|---|---|---|---|---|
| FiiO KA11 | USB dongle | $29 | 22 mW | 0.7 Ω | 1.7 µV |
| ddHiFi TC35AL | USB dongle | $46 | 22 mW | not published | not published |
| ddHiFi TC35Air | USB dongle | $46 | 22 mW | not published | not published |
Of the 280 sources here, 52 do everything the Cayin RU7 does as a headphone output: reach 100 dB on every headphone it reaches. The cheapest of them is the FiiO KA11 at $29, against this one’s $269 — $240 less.
The cheaper one also publishes an output impedance and a noise figure, which the Cayin RU7 does not — so on the paperwork it is ahead, not merely level.
This counts the headphone output only; inputs, converters, the volume control and the build are outside it.
$259 · 137 mW into 32Ω · 0.8 Ω out
Compare →$250 · 300 mW into 32Ω · 0.5 Ω out
Compare →$299 · 75 mW into 32Ω · output Ω not published
Compare →$229 · 500 mW into 32Ω · 0.3 Ω out
Compare →$219 · 125 mW into 32Ω · 0.9 Ω out
Compare →$210 · 121 mW into 32Ω · output Ω not published
Compare →Compared with its closest rivals: vs EarMen Colibri · vs Qudelix T71 · vs Questyle M15 · vs Shanling UA5.