The Zoom UAC-232 is an audio interface at $399. It delivers 148 mW into 32Ω and 28 mW into 300Ω, which ranks it 178 of 280 for raw power among the sources in this database.
Measured at 100 dB SPL it has comfortable headroom on 528 of the 567 dynamic and planar headphones catalogued here, enough but not generous on 30, only marginal on 5 and not enough power for 4. Power here is worked out from the one published figure and the published 12Ω output impedance, which is what actually governs this amplifier. Output noise is not published, so the hiss estimate cannot be run.
The manufacturer publishes 100 mW into 63Ω. The rest of the table is worked out from those.
Derived rows hold output voltage steady, as an amplifier does (method).
Source: zoomcorp.com.
| Load | Power | Status | How it was arrived at |
|---|---|---|---|
| 32 Ω | 148 mW | Derived | worked out from the published figure and the published output impedance, through the divider that impedance creates |
| 63 Ω | 100 mW | Published | the manufacturer publishes this figure at this exact load |
| 150 Ω | 51 mW | Derived | worked out from the published figure and the published output impedance, through the divider that impedance creates |
| 300 Ω | 28 mW | Derived | worked out from the published figure and the published output impedance, through the divider that impedance creates |
| 600 Ω | 14 mW | Derived | worked out from the published figure and the published output impedance, through the divider that impedance creates |
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 | +30 dB | Comfortable damping |
| 64 Audio U12t | 12.6 Ω | 108.0 dB/mW | 0.16 mW | +26 dB | Comfortable damping |
| Shure SE215 | 17 Ω | 107.0 dB/mW | 0.20 mW | +26 dB | Comfortable damping |
| Moondrop Aria | 32 Ω | 107.1 dB/mW | 0.19 mW | +29 dB | Comfortable damping |
| Audeze LCD-X 2021 | 20 Ω | 103.0 dB/mW | 0.50 mW | +23 dB | Comfortable damping |
| Truthear Hexa | 20.5 Ω | 103.1 dB/mW | 0.49 mW | +23 dB | Comfortable damping |
| Sennheiser IE 200 | 18 Ω | 101.6 dB/mW | 0.69 mW | +21 dB | Comfortable damping |
| Sony MDR-7506 | 63 Ω | 106.0 dB/mW | 0.25 mW | +26 dB | Comfortable damping |
| Meze 99 Classics | 32 Ω | 103.0 dB/mW | 0.50 mW | +25 dB | Comfortable damping |
| Focal Clear MG | 55 Ω | 104.0 dB/mW | 0.40 mW | +24 dB | Comfortable damping |
| Philips SHP9500 | 32 Ω | 101.0 dB | 0.79 mW | +23 dB | Comfortable damping |
| Focal Utopia | 80 Ω | 104.0 dB/mW | 0.40 mW | +23 dB | Comfortable damping |
| Meze Empyrean | 32 Ω | 100.0 dB | 1.0 mW | +22 dB | Comfortable damping |
| Campfire Audio Andromeda 2020 | 9 Ω | 94.0 dB | 4.0 mW | +10 dB | Comfortable damping |
| Etymotic ER2SE | 15 Ω | 96.0 dB/mW | 2.5 mW | +14 dB | Comfortable damping |
| AKG K371 | 32 Ω | 99.1 dB/mW | 1.2 mW | +21 dB | Comfortable damping |
| Audio-Technica ATH-M50X | 38 Ω | 99.0 dB/mW | 1.3 mW | +20 dB | Comfortable damping |
| Beyerdynamic DT 900 Pro X | 48 Ω | 100.0 dB/mW | 1.0 mW | +21 dB | Comfortable damping |
| Audeze LCD-2 Classic | 70 Ω | 101.0 dB/mW | 0.79 mW | +21 dB | Comfortable damping |
| Grado SR80x | 38 Ω | 98.0 dB/mW | 1.6 mW | +19 dB | Comfortable damping |
| Sennheiser HD 560S | 120 Ω | 100.8 dB/mW | 0.83 mW | +19 dB | Comfortable |
| HiFiMAN Edition XS | 18 Ω | 92.0 dB | 6.3 mW | +11 dB | Comfortable damping |
| HiFiMAN Arya Stealth | 32 Ω | 94.0 dB | 4.0 mW | +16 dB | Comfortable damping |
| Dan Clark Audio AEON 2 Closed | 13 Ω | 90.0 dB/mW | 10 mW | +8 dB | Enough damping |
| Audeze LCD-5 | 14 Ω | 90.0 dB/mW | 10 mW | +8 dB | Enough damping |
| Beyerdynamic DT 1990 Pro (250Ω) | 250 Ω | 102.0 dB/mW | 0.63 mW | +17 dB | Comfortable |
| HiFiMAN HE400se | 25 Ω | 91.0 dB | 7.9 mW | +12 dB | Comfortable damping |
| HiFiMAN Sundara | 32 Ω | 92.0 dB | 6.3 mW | +14 dB | Comfortable damping |
| Dan Clark Audio Stealth | 23 Ω | 90.0 dB/mW | 10 mW | +10 dB | Comfortable damping |
| Fostex T50RP MK3 | 50 Ω | 92.0 dB/mW | 6.3 mW | +13 dB | Comfortable damping |
| AKG K702 | 62 Ω | 92.9 dB/mW | 5.1 mW | +13 dB | Comfortable damping |
| ZMF Verite Closed | 300 Ω | 99.0 dB/mW | 1.3 mW | +13 dB | Comfortable |
| Sennheiser HD 650 | 300 Ω | 97.8 dB/mW | 1.7 mW | +12 dB | Comfortable |
| Sennheiser HD 800S | 300 Ω | 96.8 dB/mW | 2.1 mW | +11 dB | Comfortable |
| Beyerdynamic DT 770 Pro (250Ω) | 250 Ω | 96.0 dB | 2.5 mW | +11 dB | Comfortable |
| Audio-Technica ATH-R70X | 470 Ω | 98.0 dB/mW | 1.6 mW | +11 dB | Comfortable |
| ZMF Atrium | 300 Ω | 96.0 dB/mW | 2.5 mW | +10 dB | Comfortable |
| Abyss AB-1266 Phi TC | 50 Ω | 88.0 dB/mW | 16 mW | +9 dB | Enough damping |
| Sennheiser HD 600 | 300 Ω | 91.8 dB/mW | 6.6 mW | +6 dB | Enough |
| HiFiMAN Susvara | 60 Ω | 83.0 dB | 50 mW | +3 dB | Enough damping |
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.
At 12Ω output impedance, the one-eighth rule says this source suits headphones of 96.0Ω and above. 520 of the 567 models here fall below that. That is most of the database, not a niche — 222 of them multi-driver in-ears, and the mismatch tilts the frequency response audibly rather than subtly.
| Source | Type | Price | Into 300 Ω | Output impedance | Output noise |
|---|---|---|---|---|---|
| FiiO KA11 | USB dongle | $29 | 22 mW | 0.7 Ω | 1.7 µV |
| FiiO BTR13 | Bluetooth receiver | $59 | 10.0 mW | 0.6 Ω | 1.0 µV |
| FiiO KA3 | USB dongle | $79 | 14 mW | 0.5 Ω | 1.7 µV |
Of the 280 sources here, 39 do everything the Zoom UAC-232 does as a headphone output: reach 100 dB on every headphone it reaches and stay inside the one-eighth rule wherever it does. The cheapest of them is the FiiO KA11 at $29, against this one’s $399 — $370 less, and a USB dongle rather than an audio interface.
The cheaper one also publishes a noise figure, which the Zoom UAC-232 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.
$400 · 115 mW into 32Ω · <0.1 Ω out
Compare →$410 · 55 mW into 32Ω · 11 Ω out
Compare →$432 · 19 mW into 32Ω · 47 Ω out
Compare →$349 · 112 mW into 32Ω · output Ω not published
Compare →$349 · 80 mW into 32Ω · output Ω not published
Compare →$340 · 78 mW into 32Ω · 10 Ω out
Compare →Compared with its closest rivals: vs Apogee BOOM · vs Focusrite Scarlett 16i16 (4th Gen) · vs IK Multimedia AXE I/O · vs Zoom AMS-22 · vs Zoom AMS-24 · vs Zoom AMS-44.