Armature Art 12 vs Variations: which needs more amplifier?

The Moondrop Armature Art 12 is 5Ω at 98.0 dB/mW; the Moondrop Variations is 15.2Ω at 99.8 dB/mW. This page covers what they ask of an amplifier, not how they sound.

The Armature Art 12 needs 1.8 dB more than the Variations to reach the same loudness — 1.6 mW against 1.0 mW.

The numbers that decide it

SpecificationArmature Art 12Variations
Impedance5 Ω15.2 Ω
Sensitivity98.0 dB/mW99.8 dB/mW
Sensitivity (voltage)121.0 dB/V118.0 dB/V
Power for 100 dB1.6 mW1.0 mW
Voltage for 100 dB89 mV0.13 V
Current for 100 dB17.8 mA8.3 mA
Highest source impedance
that leaves them alone (one-eighth rule)
0.62 Ω1.90 Ω
Sources that reach 100 dB
out of 280
280280

Where the two part company

Every source in the database that drives one of them drives the other. On power, the choice between these two changes nothing about what amplifier you need.

51 sources are low enough in output impedance for the Variations under the one-eighth rule but not for the Armature Art 12 (FiiO SnowSky Tiny B, FiiO KA11, FiiO KA13, 48 more).

280 of the 280 sources here reach 100 dB on both.

What each one needs from 80 to 105 dB

The Variations is more demanding than 40% of the 567 non-electrostatic models in this database; the Armature Art 12 than 28%.

dB SPLArmature Art 12 powerArmature Art 12 voltageVariations powerVariations voltage
800.02 mW9 mV0.01 mW13 mV
850.05 mW16 mV0.03 mW22 mV
900.16 mW28 mV0.10 mW40 mV
950.50 mW50 mV0.33 mW71 mV
1001.6 mW89 mV1.0 mW0.13 V
1055.0 mW0.16 V3.3 mW0.22 V

The cheapest source that satisfies both

SourcePriceHeadroom, Armature Art 12Headroom, VariationsOutput impedanceNoise
JadeAudio JA11$204.7 dB11.3 dB0.5 Ω1.7 µV
FiiO BTR11$369.5 dB16.1 dB0.5 Ω8.0 µV
FiiO BTR13$5913.7 dB20.4 dB0.6 Ω1.0 µV

Of the 280 sources here, 280 reach 100 dB on both. 39 of them also publish an output impedance low enough for both under the one-eighth rule and a noise figure that stays below the audible-hiss threshold with both.

The cheapest of the 39 is the JadeAudio JA11, at $20. It leaves 4.7 dB of headroom on the Armature Art 12 and 11.3 dB on the Variations, its output impedance is 0.5 Ω against a one-eighth limit of 0.62 Ω and 1.90 Ω, and its noise figure puts the hiss floor 14 dB and 17 dB below the 20 dB SPL this site treats as the point where a quiet room stops hiding it.

Try any other source.

What each sheet prints, and what it is worth

ModelAs printedToleranceStandard
Armature Art 126Hz-34kHznot printednot printed
 20Hz-20kHz (IEC60318-4, -3dB)-3 dBIEC60318-4
Variations9-40kHz (IEC61094, Free Field)not printedIEC61094 (free field)
 20-20kHz (IEC60318-4, -3dB)-3 dBIEC60318-4

Moondrop prints two ranges, “6Hz-34kHz” and “20Hz-20kHz (IEC60318-4, -3dB)”, for the Armature Art 12 and two ranges, “9-40kHz (IEC61094, Free Field)” and “20-20kHz (IEC60318-4, -3dB)”, for the Variations.

Both sheets print a tolerance, which is rare enough to be worth pointing at: only 58 of the 490 models with a printed range do. These two ranges can be set against each other, because each of them says how far down the response is allowed to be at the ends.

Not a measurement; maker by maker.

Both pages in full

Both have a page of their own. In full: Moondrop Armature Art 12 and Moondrop Variations. Every figure on this page comes from what Moondrop published, or is derived from it — what that maker publishes, counted.

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