The Abyss AB-1266 Phi CC is 42Ω at 88.0 dB (no figure from the maker at all); the Abyss AB-1266 Phi TC is 50Ω at 88.0 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.
In amplifier terms these two are the same headphone. The gap between what they need for 100 dB is under half a decibel, which is smaller than the step between two clicks of most volume controls.
| Specification | AB-1266 Phi CC | AB-1266 Phi TC |
|---|---|---|
| Impedance | 42 Ω | 50 Ω |
| Sensitivity | 88.0 dB | 88.0 dB/mW |
| Sensitivity (voltage) | 101.8 dB/V | 101.0 dB/V |
| Power for 100 dB | 16 mW | 16 mW |
| Voltage for 100 dB | 0.82 V | 0.89 V |
| Current for 100 dB | 19.4 mA | 17.8 mA |
| Highest source impedance that leaves them alone (one-eighth rule) | 5.25 Ω | 6.25 Ω |
| Sources that reach 100 dB out of 280 | 277 | 275 |
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.
2 of the 280 sources have the power for the AB-1266 Phi CC but not for the AB-1266 Phi TC — Zoom AMS-22, Tascam US-2x2HR.
275 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.
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 AB-1266 Phi TC. 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.