The Moondrop Old Fashioned is 32Ω at 94.1 dB/mW; the Moondrop VENUS is 18Ω at 82.6 dB/mW. This page covers what they ask of an amplifier, not how they sound.
The VENUS needs 11.5 dB more than the Old Fashioned to reach the same loudness — 55 mW against 3.9 mW.
| Specification | Old Fashioned | VENUS |
|---|---|---|
| Impedance | 32 Ω | 18 Ω |
| Sensitivity | 94.1 dB/mW | 82.6 dB/mW |
| Sensitivity (voltage) | 109.0 dB/V | 100.0 dB/V |
| Power for 100 dB | 3.9 mW | 55 mW |
| Voltage for 100 dB | 0.35 V | 0.99 V |
| Current for 100 dB | 11.0 mA | 55.3 mA |
| Highest source impedance that leaves them alone (one-eighth rule) | 4.00 Ω | 2.25 Ω |
| Sources that reach 100 dB out of 280 | 280 | 225 |
55 of the 280 sources have the power for the Old Fashioned but not for the VENUS — Apple USB-C dongle (US), Apple USB-C dongle (EU), Generic CX31993 dongles, 52 more.
225 of the 280 sources here reach 100 dB on both.
The VENUS is more demanding than 98% of the 567 non-electrostatic models in this database; the Old Fashioned than 79%.
| dB SPL | Old Fashioned power | Old Fashioned voltage | VENUS power | VENUS voltage |
|---|---|---|---|---|
| 80 | 0.04 mW | 35 mV | 0.55 mW | 99 mV |
| 85 | 0.12 mW | 63 mV | 1.7 mW | 0.18 V |
| 90 | 0.39 mW | 0.11 V | 5.5 mW | 0.31 V |
| 95 | 1.2 mW | 0.20 V | 17 mW | 0.56 V |
| 100 | 3.9 mW | 0.35 V | 55 mW | 0.99 V |
| 105 | 12 mW | 0.63 V | 174 mW | 1.77 V |
| Source | Price | Headroom, Old Fashioned | Headroom, VENUS | Output impedance | Noise |
|---|---|---|---|---|---|
| FiiO KA11 | $29 | 17.1 dB | 6.3 dB | 0.7 Ω | 1.7 µV |
| FiiO BTR13 | $59 | 14.1 dB | 3.2 dB | 0.6 Ω | 1.0 µV |
| iBasso DC03 Pro | $69 | 14.0 dB | 0.0 dB | 0.12 Ω | 0.9 µV |
Of the 280 sources here, 225 reach 100 dB on both. 68 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 68 is the FiiO KA11, at $29. It leaves 17.1 dB of headroom on the Old Fashioned and 6.3 dB on the VENUS, its output impedance is 0.7 Ω against a one-eighth limit of 4.00 Ω and 2.25 Ω, and its noise figure puts the hiss floor 26 dB and 35 dB below the 20 dB SPL this site treats as the point where a quiet room stops hiding it.
| Model | As printed | Tolerance | Standard |
|---|---|---|---|
| Old Fashioned | 20Hz - 32kHz (IEC61094, Free Field) | not printed | IEC61094 (free field) |
| 20Hz - 20kHz (IEC60318-4, -3dB) | -3 dB | IEC60318-4 | |
| VENUS | 6Hz-80kHz | not printed | not printed |
| 20Hz-20kHz (IEC60318-4, ±3dB) | ±3 dB | IEC60318-4 |
Moondrop prints two ranges, “20Hz - 32kHz (IEC61094, Free Field)” and “20Hz - 20kHz (IEC60318-4, -3dB)”, for the Old Fashioned and two ranges, “6Hz-80kHz” and “20Hz-20kHz (IEC60318-4, ±3dB)”, for the VENUS.
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 Old Fashioned and Moondrop VENUS. Every figure on this page comes from what Moondrop published, or is derived from it — what that maker publishes, counted.