On power, yes — all of them. Every one of the 69 desktop amplifiers in this database reaches 100 dB SPL on the AKG K612 Pro, which needs 6.6 mW at its 120Ω.
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 JDS Labs Atom+ (2nd gen) at $99, which delivers 558 mW into 120Ω — 19 dB of headroom over the 6.6 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 0.21 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 AKG K612 Pro wants a source below 15.00Ω. Of the 49 desktop amplifiers here that publish an output impedance, 46 are under it and 3 are not.
The furthest over is the Bottlehead Crack (OTL kit) at 120Ω, which is 8× 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 20 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 91.8 dB/mW and 120Ω, the AKG K612 Pro turns one microvolt of source noise into about -19 dB SPL — and the threshold where that stops being noticeable in a quiet room is around 20 dB SPL.
Of the 21 desktop amplifiers here that publish a noise figure, 21 stay below that threshold with this headphone and 0 cross it.
The remaining 48 publish no noise figure, so they cannot be placed on either side.
| Source | Price | Into 120Ω | Output impedance | Hiss in these | Power verdict |
|---|---|---|---|---|---|
| JDS Labs Atom+ (2nd gen) | $99 | 558 mW | 0.7 Ω | -13 dB SPL | Comfortable |
| Schiit Magni Heresy | $99 | 759 mW | 0.25 Ω | not published | Comfortable |
| Schiit Magni+ | $109 | 655 mW | not published | not published | Comfortable |
| Schiit Magni Unity | $119 | 730 mW | 0.1 Ω | not published | Comfortable |
| JDS Labs Atom Amp 2 | $129 | 708 mW | 0.7 Ω | -17 dB SPL | Comfortable |
| Schiit Vali 2+ | $149 | 555 mW | 1.8 Ω | not published | Comfortable |
| Schiit Vali 3 | $149 | 555 mW | 0.5 Ω | not published | Comfortable |
| Topping L30 II | $149 | 1.1 W | 0.1 Ω | -29 dB SPL | Comfortable |
| SMSL HO100 | $160 | 432 mW | <0.1 Ω | -17 dB SPL | Comfortable |
| xDuoo MT-604 | $169 | 533 mW | not published | not published | Comfortable |
| Little Dot MK II | $176 | 200 mW | not published | not published | Comfortable |
| iFi Zen CAN | $199 | 467 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 AKG K612 Pro on other categories: USB dongles · portable players · audio interfaces.
The AKG K612 Pro page has every source in the database against this headphone, and the matcher takes your own numbers.