Andromeda 2020 vs Solaris 2020: which needs more amplifier?

The Campfire Audio Andromeda 2020 is 9Ω at 94.0 dB (no figure from the maker at all); the Campfire Audio Solaris 2020 is 15Ω 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.

In amplifier terms these two are the same headphone. The gap between what they need for 100 dB is under half a decibel, which is smaller than the step between two clicks of most volume controls.

The numbers that decide it

SpecificationAndromeda 2020Solaris 2020
Impedance9 Ω15 Ω
Sensitivity94.0 dB94.0 dB
Sensitivity (voltage)114.5 dB/V112.2 dB/V
Power for 100 dB4.0 mW4.0 mW
Voltage for 100 dB0.19 V0.24 V
Current for 100 dB21.0 mA16.3 mA
Highest source impedance
that leaves them alone (one-eighth rule)
1.12 Ω1.88 Ω
Sources that reach 100 dB
out of 280
279280

One caution before reading the rows. For Campfire Audio Andromeda 2020 and Campfire Audio Solaris 2020 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

1 of the 280 sources has the power for the Solaris 2020 but not for the Andromeda 2020 — Steinberg UR22C.

8 sources are low enough in output impedance for the Solaris 2020 under the one-eighth rule but not for the Andromeda 2020 (FiiO KA13, FiiO K11, Schiit Vali 2+, 5 more).

279 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 2020 and Campfire Audio Solaris 2020. 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.