The Focusrite Scarlett Solo 4th gen is an audio interface at $139. It delivers 31 mW into 32Ω and 22 mW into 300Ω, which ranks it 258 of 280 for raw power among the sources in this database.
Measured at 100 dB SPL it has comfortable headroom on 413 of the 567 dynamic and planar headphones catalogued here, enough but not generous on 123, only marginal on 16 and not enough power for 15. Power is published at 33Ω, 300Ω; the rest of the table is derived from those figures. Output noise is not published, so the hiss estimate cannot be run.
The manufacturer publishes 32 mW into 33Ω, 22 mW into 300Ω. The rest of the table is worked out from those.
Derived rows hold output voltage steady, as an amplifier does (method).
Source: userguides.focusrite.com.
| Load | Power | Status | How it was arrived at |
|---|---|---|---|
| 32 Ω | 31 mW | Derived | beyond the published loads, holding output voltage constant — which understates rather than flatters |
| 33 Ω | 32 mW | Published | the manufacturer publishes this figure at this exact load |
| 150 Ω | 19 mW | Derived | worked out between two published loads, holding output voltage linear between them |
| 300 Ω | 22 mW | Published | the manufacturer publishes this figure at this exact load |
| 600 Ω | 11 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 | +23 dB | Comfortable damping |
| 64 Audio U12t | 12.6 Ω | 108.0 dB/mW | 0.16 mW | +19 dB | Comfortable damping |
| Shure SE215 | 17 Ω | 107.0 dB/mW | 0.20 mW | +19 dB | Comfortable damping |
| Moondrop Aria | 32 Ω | 107.1 dB/mW | 0.19 mW | +22 dB | Comfortable damping |
| Audeze LCD-X 2021 | 20 Ω | 103.0 dB/mW | 0.50 mW | +16 dB | Comfortable damping |
| Truthear Hexa | 20.5 Ω | 103.1 dB/mW | 0.49 mW | +16 dB | Comfortable damping |
| Sennheiser IE 200 | 18 Ω | 101.6 dB/mW | 0.69 mW | +14 dB | Comfortable damping |
| Sony MDR-7506 | 63 Ω | 106.0 dB/mW | 0.25 mW | +20 dB | Comfortable damping |
| Meze 99 Classics | 32 Ω | 103.0 dB/mW | 0.50 mW | +18 dB | Comfortable damping |
| Focal Clear MG | 55 Ω | 104.0 dB/mW | 0.40 mW | +18 dB | Comfortable damping |
| Philips SHP9500 | 32 Ω | 101.0 dB | 0.79 mW | +16 dB | Comfortable damping |
| Focal Utopia | 80 Ω | 104.0 dB/mW | 0.40 mW | +17 dB | Comfortable damping |
| Meze Empyrean | 32 Ω | 100.0 dB | 1.0 mW | +15 dB | Comfortable damping |
| Campfire Audio Andromeda 2020 | 9 Ω | 94.0 dB | 4.0 mW | +3 dB | Enough damping |
| Etymotic ER2SE | 15 Ω | 96.0 dB/mW | 2.5 mW | +8 dB | Enough damping |
| AKG K371 | 32 Ω | 99.1 dB/mW | 1.2 mW | +14 dB | Comfortable damping |
| Audio-Technica ATH-M50X | 38 Ω | 99.0 dB/mW | 1.3 mW | +14 dB | Comfortable damping |
| Beyerdynamic DT 900 Pro X | 48 Ω | 100.0 dB/mW | 1.0 mW | +14 dB | Comfortable damping |
| Audeze LCD-2 Classic | 70 Ω | 101.0 dB/mW | 0.79 mW | +14 dB | Comfortable damping |
| Grado SR80x | 38 Ω | 98.0 dB/mW | 1.6 mW | +13 dB | Comfortable damping |
| Sennheiser HD 560S | 120 Ω | 100.8 dB/mW | 0.83 mW | +14 dB | Comfortable damping |
| HiFiMAN Edition XS | 18 Ω | 92.0 dB | 6.3 mW | +4 dB | Enough damping |
| HiFiMAN Arya Stealth | 32 Ω | 94.0 dB | 4.0 mW | +9 dB | Enough damping |
| Dan Clark Audio AEON 2 Closed | 13 Ω | 90.0 dB/mW | 10 mW | +1 dB | Marginal damping |
| Audeze LCD-5 | 14 Ω | 90.0 dB/mW | 10 mW | +1 dB | Marginal damping |
| Beyerdynamic DT 1990 Pro (250Ω) | 250 Ω | 102.0 dB/mW | 0.63 mW | +15 dB | Comfortable damping |
| HiFiMAN HE400se | 25 Ω | 91.0 dB | 7.9 mW | +5 dB | Enough damping |
| HiFiMAN Sundara | 32 Ω | 92.0 dB | 6.3 mW | +7 dB | Enough damping |
| Dan Clark Audio Stealth | 23 Ω | 90.0 dB/mW | 10 mW | +3 dB | Enough damping |
| Fostex T50RP MK3 | 50 Ω | 92.0 dB/mW | 6.3 mW | +6 dB | Enough damping |
| AKG K702 | 62 Ω | 92.9 dB/mW | 5.1 mW | +7 dB | Enough damping |
| ZMF Verite Closed | 300 Ω | 99.0 dB/mW | 1.3 mW | +12 dB | Comfortable damping |
| Sennheiser HD 650 | 300 Ω | 97.8 dB/mW | 1.7 mW | +11 dB | Comfortable damping |
| Sennheiser HD 800S | 300 Ω | 96.8 dB/mW | 2.1 mW | +10 dB | Comfortable damping |
| Beyerdynamic DT 770 Pro (250Ω) | 250 Ω | 96.0 dB | 2.5 mW | +9 dB | Enough damping |
| Audio-Technica ATH-R70X | 470 Ω | 98.0 dB/mW | 1.6 mW | +9 dB | Enough |
| ZMF Atrium | 300 Ω | 96.0 dB/mW | 2.5 mW | +9 dB | Enough damping |
| Abyss AB-1266 Phi TC | 50 Ω | 88.0 dB/mW | 16 mW | +2 dB | Marginal damping |
| Sennheiser HD 600 | 300 Ω | 91.8 dB/mW | 6.6 mW | +5 dB | Enough damping |
| HiFiMAN Susvara | 60 Ω | 83.0 dB | 50 mW | -3 dB | Not 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 50Ω output impedance, the one-eighth rule says this source suits headphones of 400.0Ω and above. 561 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.
| Product | Price |
|---|---|
| Focusrite Scarlett Solo 4th gen | $139 |
| Focusrite Scarlett 2i2 4th gen | $199 |
On every figure Focusrite publishes for this headphone output, the Focusrite Scarlett Solo 4th gen is identical to the Focusrite Scarlett 2i2 4th gen. Each of them states power at 33 Ω and at 300 Ω and an output impedance of 50 Ω — and each states the same values.
They do not cost the same. The spread across the 2 of them is $60, and none of that difference is visible in the figures above.
Identical published figures do not mean identical products. A spec sheet for a headphone output covers power, output impedance and noise. It says nothing about the converter, the inputs, the case, the battery, the volume control or how any of it sounds, and those are real differences that cost real money. What this section says is narrower and worth saying anyway: if you are choosing between these on what the maker printed about the headphone jack, there is nothing to choose.
15 groups of products in this database share a spec sheet this way, 36 products in all.
| 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 |
| iFi GO link | USB dongle | $59 | 14 mW | 0.4 Ω | not published |
Of the 280 sources here, 16 do everything the Focusrite Scarlett Solo 4th gen 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 $139 — $110 less, and a USB dongle rather than an audio interface.
The cheaper one also publishes a noise figure, which the Focusrite Scarlett Solo 4th gen 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.
$130 · 26 mW into 32Ω · <0.1 Ω out
Compare →$129 · 22 mW into 32Ω · 50 Ω out
Compare →$149 · 27 mW into 32Ω · output Ω not published
Compare →$149 · 139 mW into 32Ω · 10 Ω out
Compare →$149 · 84 mW into 32Ω · output Ω not published
Compare →$149 · 139 mW into 32Ω · 10 Ω out
Compare →Compared with its closest rivals: vs Arturia MiniFuse 1 · vs Audient EVO 4 · vs Focusrite Scarlett 16i16 (4th Gen) · vs Focusrite Scarlett 18i16 (4th Gen) · vs Focusrite Scarlett 18i20 4th gen · vs Focusrite Scarlett 4i4 4th gen · vs Focusrite Vocaster Two · vs IK Multimedia AXE I/O ONE · vs Zoom AMS-22.