Abyss AB-1266 Phi TC vs Focal Utopia: which needs more amplifier?

The Abyss AB-1266 Phi TC is 50Ω at 88.0 dB/mW; the Focal Utopia is 80Ω at 104.0 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 16.0 dB more than the Focal Utopia to reach the same loudness — 16 mW against 0.40 mW.

The numbers that decide it

SpecificationAbyss AB-1266 Phi TCFocal Utopia
Impedance50 Ω80 Ω
Sensitivity88.0 dB/mW104.0 dB/mW
Sensitivity (voltage)101.0 dB/V115.0 dB/V
Power for 100 dB16 mW0.40 mW
Voltage for 100 dB0.89 V0.18 V
Current for 100 dB17.8 mA2.2 mA
Highest source impedance
that leaves them alone (one-eighth rule)
6.25 Ω10.00 Ω
Sources that reach 100 dB
out of 280
275280

Where the two part company

5 of the 280 sources have the power for the Focal Utopia but not for the Abyss AB-1266 Phi TC — Apple USB-C dongle (EU), Zoom AMS-22, Steinberg UR22C, 2 more.

9 sources are low enough in output impedance for the Focal Utopia under the one-eighth rule but not for the Abyss AB-1266 Phi TC (Zoom AMS-22, Arturia MiniFuse 2, Arturia MiniFuse 1, 6 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.

Both pages in full

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 Focal Utopia. Every figure on this page comes from what Abyss and Focal published, or is derived from it — what Abyss publishes and what Focal publishes, both counted.