The Abyss AB-1266 Phi TC is 50Ω at 88.0 dB/mW; the Meze 109 Pro is 40Ω at 112.0 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 24.0 dB more than the Meze 109 Pro to reach the same loudness — 16 mW against 0.06 mW.
| Specification | Abyss AB-1266 Phi TC | Meze 109 Pro |
|---|---|---|
| Impedance | 50 Ω | 40 Ω |
| Sensitivity | 88.0 dB/mW | 112.0 dB/mW |
| Sensitivity (voltage) | 101.0 dB/V | 126.0 dB/V |
| Power for 100 dB | 16 mW | 0.06 mW |
| Voltage for 100 dB | 0.89 V | 50 mV |
| Current for 100 dB | 17.8 mA | 1.3 mA |
| Highest source impedance that leaves them alone (one-eighth rule) | 6.25 Ω | 5.00 Ω |
| Sources that reach 100 dB out of 280 | 275 | 280 |
5 of the 280 sources have the power for the Meze 109 Pro but not for the Abyss AB-1266 Phi TC — Apple USB-C dongle (EU), Zoom AMS-22, Steinberg UR22C, 2 more.
13 sources stay below the audible-hiss threshold with the Abyss AB-1266 Phi TC but cross it with the Meze 109 Pro (FiiO BTR11, FiiO K11 R2R, Lake People G103-S Mk II, 10 more).
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 TC and Meze 109 Pro. Every figure on this page comes from what Abyss and Meze published, or is derived from it — what Abyss publishes and what Meze publishes, both counted.