On power, yes — all of them. Every one of the 65 audio interfaces in this database reaches 100 dB SPL on the Moondrop Variations, which needs 1.0 mW at its 15.2Ω.
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 cheapest one that does reach it is the Zoom AMS-22 at $100, which delivers 9.5 mW into 15.2Ω — 10 dB of headroom over the 1.0 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 0.03 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 Moondrop Variations wants a source below 1.90Ω. Of the 43 audio interfaces here that publish an output impedance, 13 are under it and 30 are not.
The furthest over is the Tascam US-2x2HR at 66Ω, which is 35× 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 22 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 99.8 dB/mW and 15.2Ω, the Moondrop Variations turns one microvolt of source noise into about -2 dB SPL — and the threshold where that stops being noticeable in a quiet room is around 20 dB SPL.
Of the 4 audio interfaces here that publish a noise figure, 4 stay below that threshold with this headphone and 0 cross it.
The remaining 61 publish no noise figure, so they cannot be placed on either side.
| Source | Price | Into 15.2 Ω | Headroom | Output impedance | Hiss in these |
|---|---|---|---|---|---|
| RME ADI-2 DAC FS | $1399 | 893 mW | 29.3 dB | 0.1 Ω | 5 dB SPL |
| RME ADI-2 Pro FS R | $2199 | 1.4 W | 31.3 dB | 0.1 Ω | 5 dB SPL |
| RME ADI-2 Pro EX | $2499 | 2.0 W | 32.8 dB | 0.1 Ω | 5 dB SPL |
4 of the 65 audio interfaces here publish all three figures. 3 of those clear all three for the Moondrop Variations, and the cheapest is the RME ADI-2 DAC FS at $1399.
It delivers 893 mW into 15.2 Ω where this headphone needs 1.0 mW for 100 dB — 29.3 dB of headroom — its output impedance of 0.1 Ω sits under the one-eighth ceiling of 1.90 Ω, and its 2.18 µV of noise leaves the hiss 15 dB under the 20 dB SPL threshold this site uses.
Cheapest that satisfies three published numbers is not the same as best, and the sources left out of this count are left out for want of a published figure, not for failing one. How often that happens is its own page.
| Source | Price | Into 15.2Ω | Output impedance | Hiss in these | Power verdict |
|---|---|---|---|---|---|
| Steinberg IXO22 | $119 | 15 mW | not published | not published | Comfortable |
| IK Multimedia AXE I/O ONE | $130 | 12 mW | <0.1 Ω | not published | Comfortable |
| PreSonus Studio 24c | $149 | 13 mW | not published | not published | Comfortable |
| Universal Audio Volt 1 | $149 | 40 mW | not published | not published | Comfortable |
| Steinberg UR24C | $194 | 38 mW | not published | not published | Comfortable |
| Audient iD4 MkII | $199 | 56 mW | not published | not published | Comfortable |
| PreSonus Quantum ES 2 | $199 | 50 mW | not published | not published | Comfortable |
| Universal Audio Volt 2 | $199 | 40 mW | not published | not published | Comfortable |
| MOTU M2 | $219 | 158 mW | not published | not published | Comfortable |
| SSL 2 MkII | $229 | 178 mW | 1 Ω | not published | Comfortable |
| Focusrite Vocaster Two | $250 | 13 mW | not published | not published | Comfortable |
| MOTU M4 | $279 | 158 mW | not published | not published | Comfortable |
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 Moondrop Variations on other categories: USB dongles · portable players · desktop amplifiers · desktop DAC/amps.
The Moondrop Variations page has every source in the database against this headphone, and the matcher takes your own numbers.