Andromeda 10 vs Ara: which needs more amplifier?

The Campfire Audio Andromeda 10 is 8.5Ω at 111.6 dB/mW; the Campfire Audio Ara is 8Ω at 94.0 dB (no figure from the maker at all). 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 Ara needs 17.6 dB more than the Andromeda 10 to reach the same loudness — 4.0 mW against 0.07 mW.

The numbers that decide it

SpecificationAndromeda 10Ara
Impedance8.5 Ω8 Ω
Sensitivity111.6 dB/mW94.0 dB
Sensitivity (voltage)132.3 dB/V115.0 dB/V
Power for 100 dB0.07 mW4.0 mW
Voltage for 100 dB24 mV0.18 V
Current for 100 dB2.9 mA22.3 mA
Highest source impedance
that leaves them alone (one-eighth rule)
1.06 Ω1.00 Ω
Sources that reach 100 dB
out of 280
280278

One caution before reading the rows. For Campfire Audio Ara 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.

Where the two part company

2 of the 280 sources have the power for the Andromeda 10 but not for the Ara — Apple USB-C dongle (EU), Steinberg UR22C.

32 sources stay below the audible-hiss threshold with the Ara but cross it with the Andromeda 10 (Kiwi Ears Allegro Mini, FiiO BTR11, FiiO KA13, 29 more).

278 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: Campfire Audio Andromeda 10 and Campfire Audio Ara. Each figure on this page is labelled on those pages with where it came from, including the ones Campfire Audio never published — what that maker publishes, counted.