The Abyss AB-1266 Phi TC is 50Ω at 88.0 dB/mW; the Audeze LCD-5 is 14Ω at 90.0 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 Abyss AB-1266 Phi TC needs 2.0 dB more than the Audeze LCD-5 to reach the same loudness — 16 mW against 10 mW.
| Specification | Abyss AB-1266 Phi TC | Audeze LCD-5 |
|---|---|---|
| Impedance | 50 Ω | 14 Ω |
| Sensitivity | 88.0 dB/mW | 90.0 dB/mW |
| Sensitivity (voltage) | 101.0 dB/V | 108.5 dB/V |
| Power for 100 dB | 16 mW | 10 mW |
| Voltage for 100 dB | 0.89 V | 0.37 V |
| Current for 100 dB | 17.8 mA | 26.7 mA |
| Highest source impedance that leaves them alone (one-eighth rule) | 6.25 Ω | 1.75 Ω |
| Sources that reach 100 dB out of 280 | 275 | 274 |
2 of the 280 sources have the power for the Abyss AB-1266 Phi TC but not for the Audeze LCD-5 — Roland Rubix22, Roland Rubix44.
1 of the 280 sources has the power for the Audeze LCD-5 but not for the Abyss AB-1266 Phi TC — Sony NW-A306.
5 sources are low enough in output impedance for the Abyss AB-1266 Phi TC under the one-eighth rule but not for the Audeze LCD-5 (Schiit Vali 2+, Astell&Kern HC3, Shanling H5, 2 more).
273 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 TC and Audeze LCD-5. Every figure on this page comes from what Abyss and Audeze published, or is derived from it — what Abyss publishes and what Audeze publishes, both counted.