The Moondrop Armature Art 24 is 5.8Ω at 96.6 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 24 needs 3.2 dB more than the Variations to reach the same loudness — 2.2 mW against 1.0 mW.
| Specification | Armature Art 24 | Variations |
|---|---|---|
| Impedance | 5.8 Ω | 15.2 Ω |
| Sensitivity | 96.6 dB/mW | 99.8 dB/mW |
| Sensitivity (voltage) | 119.0 dB/V | 118.0 dB/V |
| Power for 100 dB | 2.2 mW | 1.0 mW |
| Voltage for 100 dB | 0.11 V | 0.13 V |
| Current for 100 dB | 19.4 mA | 8.3 mA |
| Highest source impedance that leaves them alone (one-eighth rule) | 0.72 Ω | 1.90 Ω |
| Sources that reach 100 dB out of 280 | 279 | 280 |
1 of the 280 sources has the power for the Variations but not for the Armature Art 24 — Steinberg UR22C.
46 sources are low enough in output impedance for the Variations under the one-eighth rule but not for the Armature Art 24 (FiiO SnowSky Tiny B, FiiO KA13, FiiO KA15, 43 more).
279 of the 280 sources here reach 100 dB on both.
The Variations is more demanding than 40% of the 567 non-electrostatic models in this database; the Armature Art 24 than 37%.
| dB SPL | Armature Art 24 power | Armature Art 24 voltage | Variations power | Variations voltage |
|---|---|---|---|---|
| 80 | 0.02 mW | 11 mV | 0.01 mW | 13 mV |
| 85 | 0.07 mW | 20 mV | 0.03 mW | 22 mV |
| 90 | 0.22 mW | 36 mV | 0.10 mW | 40 mV |
| 95 | 0.69 mW | 63 mV | 0.33 mW | 71 mV |
| 100 | 2.2 mW | 0.11 V | 1.0 mW | 0.13 V |
| 105 | 6.9 mW | 0.20 V | 3.3 mW | 0.22 V |
| Source | Price | Headroom, Armature Art 24 | Headroom, Variations | Output impedance | Noise |
|---|---|---|---|---|---|
| JadeAudio JA11 | $20 | 4.0 dB | 11.3 dB | 0.5 Ω | 1.7 µV |
| FiiO KA11 | $29 | 16.1 dB | 23.5 dB | 0.7 Ω | 1.7 µV |
| FiiO BTR11 | $36 | 8.7 dB | 16.1 dB | 0.5 Ω | 8.0 µV |
Of the 280 sources here, 279 reach 100 dB on both. 43 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 43 is the JadeAudio JA11, at $20. It leaves 4.0 dB of headroom on the Armature Art 24 and 11.3 dB on the Variations, its output impedance is 0.5 Ω against a one-eighth limit of 0.72 Ω and 1.90 Ω, and its noise figure puts the hiss floor 16 dB and 17 dB below the 20 dB SPL this site treats as the point where a quiet room stops hiding it.
| Model | As printed | Tolerance | Standard |
|---|---|---|---|
| Armature Art 24 | 7Hz-35kHz | not printed | not printed |
| 20Hz-20kHz (IEC60318-4, -3dB) | -3 dB | IEC60318-4 | |
| Variations | 9-40kHz (IEC61094, Free Field) | not printed | IEC61094 (free field) |
| 20-20kHz (IEC60318-4, -3dB) | -3 dB | IEC60318-4 |
Moondrop prints two ranges, “7Hz-35kHz” and “20Hz-20kHz (IEC60318-4, -3dB)”, for the Armature Art 24 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 have a page of their own. In full: Moondrop Armature Art 24 and Moondrop Variations. Every figure on this page comes from what Moondrop published, or is derived from it — what that maker publishes, counted.