Abyss AB-1266 Phi TC vs Dan Clark Audio Stealth: which needs more amplifier?

The Abyss AB-1266 Phi TC is 50Ω at 88.0 dB/mW; the Dan Clark Audio Stealth is 23Ω 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 Dan Clark Audio Stealth to reach the same loudness — 16 mW against 10 mW.

The numbers that decide it

SpecificationAbyss AB-1266 Phi TCDan Clark Audio Stealth
Impedance50 Ω23 Ω
Sensitivity88.0 dB/mW90.0 dB/mW
Sensitivity (voltage)101.0 dB/V106.4 dB/V
Power for 100 dB16 mW10 mW
Voltage for 100 dB0.89 V0.48 V
Current for 100 dB17.8 mA20.9 mA
Highest source impedance
that leaves them alone (one-eighth rule)
6.25 Ω2.88 Ω
Sources that reach 100 dB
out of 280
275279

Where the two part company

4 of the 280 sources have the power for the Dan Clark Audio Stealth but not for the Abyss AB-1266 Phi TC — Apple USB-C dongle (EU), Zoom AMS-22, Tascam US-2x2HR, 1 more.

1 source is low enough in output impedance for the Abyss AB-1266 Phi TC under the one-eighth rule but not for the Dan Clark Audio Stealth (Shanling H5).

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 Dan Clark Audio Stealth. Every figure on this page comes from what Abyss and Dan Clark Audio published, or is derived from it — what Abyss publishes and what Dan Clark Audio publishes, both counted.