The Abyss AB-1266 Phi CC is 42Ω at 88.0 dB (no figure from the maker at all); the Abyss Diana V2 is 42Ω at 91.0 dB/mW. This page is only about what they ask of an amplifier — not how they sound, which no specification on either sheet can tell you.
The AB-1266 Phi CC needs 3.0 dB more than the Diana V2 to reach the same loudness — 16 mW against 7.9 mW.
| Specification | AB-1266 Phi CC | Diana V2 |
|---|---|---|
| Impedance | 42 Ω | 42 Ω |
| Sensitivity | 88.0 dB | 91.0 dB/mW |
| Sensitivity (voltage) | 101.8 dB/V | 104.8 dB/V |
| Power for 100 dB | 16 mW | 7.9 mW |
| Voltage for 100 dB | 0.82 V | 0.58 V |
| Current for 100 dB | 19.4 mA | 13.8 mA |
| Highest source impedance that leaves them alone (one-eighth rule) | 5.25 Ω | 5.25 Ω |
| Sources that reach 100 dB out of 280 | 277 | 280 |
One caution before reading the rows. For Abyss AB-1266 Phi CC the maker publishes no sensitivity figure at all. The number in the table was collected when this database was first built and has never been traced to a manufacturer document, so treat every row below it as an estimate rather than a specification.
3 of the 280 sources have the power for the Diana V2 but not for the AB-1266 Phi CC — Apple USB-C dongle (EU), Steinberg UR22C, Sony NW-A306.
277 of the 280 sources here reach 100 dB on both. That count is about power only — the output-impedance and hiss lines above are separate questions, and a source can pass this one and fail those.
The gap between these two in decibels does not change with volume — it is a property of the two headphones. What changes is the size of the numbers, and it changes fast: every 10 dB costs ten times the power. The row that matters is the one nearest the level you listen at, and for most people that is nearer the top of this table than the bottom.
The AB-1266 Phi CC is more demanding than 96% of the 567 non-electrostatic models in this database; the Diana V2 than 90%. Both figures use the same measure as the rest of the site: whichever runs out first against a 2 V, 100 mW dongle, voltage or power.
| dB SPL | AB-1266 Phi CC power | AB-1266 Phi CC voltage | Diana V2 power | Diana V2 voltage |
|---|---|---|---|---|
| 80 | 0.16 mW | 82 mV | 0.08 mW | 58 mV |
| 85 | 0.50 mW | 0.15 V | 0.25 mW | 0.10 V |
| 90 | 1.6 mW | 0.26 V | 0.79 mW | 0.18 V |
| 95 | 5.0 mW | 0.46 V | 2.5 mW | 0.32 V |
| 100 | 16 mW | 0.82 V | 7.9 mW | 0.58 V |
| 105 | 50 mW | 1.45 V | 25 mW | 1.03 V |
105 dB is included because forum power figures are usually quoted there or higher. It is also a level that damages hearing in minutes — how many minutes is its own calculator.
| Source | Price | Headroom, AB-1266 Phi CC | Headroom, Diana V2 | Output impedance | Noise |
|---|---|---|---|---|---|
| JadeAudio JA11 | $20 | 1.6 dB | 4.6 dB | 0.5 Ω | 1.7 µV |
| FiiO KA11 | $29 | 9.8 dB | 12.8 dB | 0.7 Ω | 1.7 µV |
| FiiO BTR11 | $36 | 1.6 dB | 4.6 dB | 0.5 Ω | 8.0 µV |
Of the 280 sources here, 277 reach 100 dB on both. That is the easy axis. 70 of them also publish an output impedance low enough for both under the one-eighth rule and a noise figure that stays below the audible-hiss threshold with both — the rest either fail one of those or never printed the number at all, and 205 of them are in the second group.
The cheapest of the 70 is the JadeAudio JA11, at $20. It leaves 1.6 dB of headroom on the AB-1266 Phi CC and 4.6 dB on the Diana V2, its output impedance is 0.5 Ω against a one-eighth limit of 5.25 Ω for both, and its noise figure puts the hiss floor 34 dB and 31 dB below the 20 dB SPL this site treats as the point where a quiet room stops hiding it.
Cheapest that satisfies three published numbers is not the same as best, and none of it is about how either headphone sounds. To put either model against a source this page does not mention, or to change the target loudness, use the amplifier matcher.
Each model has a page of its own with the full source list, the hiss estimate and the provenance of every figure above: Abyss AB-1266 Phi CC and Abyss Diana V2. Each figure on this page is labelled on those pages with where it came from, including the ones Abyss never published — what that maker publishes, counted.