On power: 50 of the 51 USB dongles here reach 100 dB SPL on the Dan Clark Audio AEON 2 Closed. It needs 10 mW at its 13Ω, and 1 of them do not get there.
Power is one of three questions and the one that goes wrong least often. The other two — whether the source’s output impedance leaves the frequency response alone, and whether you will hear its noise floor — are answered further down, separately, because a source can pass one and fail another.
The 1 that fall short are Apple USB-C dongle (EU). The closest of them, the Apple USB-C dongle (EU), delivers 6.1 mW into 13Ω against the 10 mW needed — 2.2 dB short.
The cheapest one that does reach it is the Apple USB-C dongle (US) at $9, which delivers 12 mW into 13Ω — 1 dB of headroom over the 10 mW this headphone needs for 100 dB SPL.
100 dB SPL is a peak level, not a listening level. If you listen at 85 dB the same headphone needs 0.32 mW, which is 15 dB less, and the answer above changes for most of the category. The model page has the full ladder.
Under the one-eighth rule the Dan Clark Audio AEON 2 Closed wants a source below 1.62Ω. Of the 18 USB dongles here that publish an output impedance, 16 are under it and 2 are not.
The furthest over is the Astell&Kern HC3 at 2Ω, which is 1× the ceiling. Above that threshold the source stops being a volume control and starts being part of the frequency response. The simulator shows what that looks like.
The other 33 publish nothing at all on this, so they are not on either side of that count. This site leaves them blank rather than assuming a figure.
Hiss depends on the source’s own noise floor and on how sensitive the headphone is. At 90.0 dB/mW and 13Ω, the Dan Clark Audio AEON 2 Closed turns one microvolt of source noise into about -11 dB SPL — and the threshold where that stops being noticeable in a quiet room is around 20 dB SPL.
Of the 16 USB dongles here that publish a noise figure, 16 stay below that threshold with this headphone and 0 cross it.
The remaining 35 publish no noise figure, so they cannot be placed on either side.
| Source | Price | Into 13Ω | Output impedance | Hiss in these | Power verdict |
|---|---|---|---|---|---|
| FiiO KA11 | $29 | 199 mW | 0.7 Ω | -7 dB SPL | Comfortable |
| Tempotec Sonata BHD Pro | $60 | 114 mW | not published | not published | Comfortable |
| FiiO KA5 | $99 | 111 mW | 0.3 Ω | -7 dB SPL | Comfortable |
| ddHiFi TC44 Pro E2 | $99 | 102 mW | not published | not published | Comfortable |
| FiiO KA15 | $109 | 236 mW | 0.8 Ω | -7 dB SPL | Comfortable |
| Tanchjim LUNA | $140 | 142 mW | not published | -9 dB SPL | Comfortable |
| Moondrop Moonriver 2 Ti | $190 | 114 mW | not published | -8 dB SPL | Comfortable |
| THX Onyx | $200 | 106 mW | 0.2 Ω | not published | Comfortable |
| Qudelix T71 | $229 | 203 mW | not published | not published | Comfortable |
| Questyle M15 | $250 | 122 mW | not published | not published | Comfortable |
| EarMen Colibri | $299 | 122 mW | not published | not published | Comfortable |
| Generic CX31993 dongles | $12 | 24 mW | not published | not published | Enough |
Sorted by how many of the three questions the source answers well, then by price. A blank in a column is a blank in the manufacturer’s own documentation, not a zero.
The Dan Clark Audio AEON 2 Closed on other categories: portable players · desktop amplifiers · desktop DAC/amps · audio interfaces.
The Dan Clark Audio AEON 2 Closed page has every source in the database against this headphone, and the matcher takes your own numbers.