Chimera vs Holocene: which needs more amplifier?

The Campfire Audio Chimera is 5.5Ω at 108.1 dB/mW; the Campfire Audio Holocene is 9Ω 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 Holocene needs 14.1 dB more than the Chimera to reach the same loudness — 4.0 mW against 0.15 mW.

The numbers that decide it

SpecificationChimeraHolocene
Impedance5.5 Ω9 Ω
Sensitivity108.1 dB/mW94.0 dB
Sensitivity (voltage)130.7 dB/V114.5 dB/V
Power for 100 dB0.15 mW4.0 mW
Voltage for 100 dB29 mV0.19 V
Current for 100 dB5.3 mA21.0 mA
Highest source impedance
that leaves them alone (one-eighth rule)
0.69 Ω1.12 Ω
Sources that reach 100 dB
out of 280
280279

One caution before reading the rows. For Campfire Audio Holocene 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 Chimera but not for the Holocene — Steinberg UR22C.

43 sources are low enough in output impedance for the Holocene under the one-eighth rule but not for the Chimera (FiiO SnowSky Tiny B, FiiO KA11, JDS Labs Atom+ (2nd gen), 40 more).

25 sources stay below the audible-hiss threshold with the Holocene but cross it with the Chimera (Kiwi Ears Allegro Mini, FiiO BTR11, FiiO K11 R2R, 22 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 Chimera and Campfire Audio Holocene. 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.