The FiiO FT3 (350Ω) is 350Ω at 100.4 dB/mW; the FiiO JT1 is 32Ω at 88.1 dB/mW. This page covers what they ask of an amplifier, not how they sound.
The JT1 needs 12.3 dB more than the FT3 (350Ω) to reach the same loudness — 15 mW against 0.91 mW.
| Specification | FT3 (350Ω) | JT1 |
|---|---|---|
| Impedance | 350 Ω | 32 Ω |
| Sensitivity | 100.4 dB/mW | 88.1 dB/mW |
| Sensitivity (voltage) | 105.0 dB/V | 103.0 dB/V |
| Power for 100 dB | 0.91 mW | 15 mW |
| Voltage for 100 dB | 0.56 V | 0.70 V |
| Current for 100 dB | 1.6 mA | 22.0 mA |
| Highest source impedance that leaves them alone (one-eighth rule) | 43.75 Ω | 4.00 Ω |
| Sources that reach 100 dB out of 280 | 280 | 278 |
2 of the 280 sources have the power for the FT3 (350Ω) but not for the JT1 — Apple USB-C dongle (EU), Steinberg UR22C.
20 sources are low enough in output impedance for the FT3 (350Ω) under the one-eighth rule but not for the JT1 (Zoom AMS-22, Arturia MiniFuse 2, Arturia MiniFuse 1, 17 more).
278 of the 280 sources here reach 100 dB on both.
The JT1 is more demanding than 93% of the 567 non-electrostatic models in this database; the FT3 (350Ω) than 89%.
| dB SPL | FT3 (350Ω) power | FT3 (350Ω) voltage | JT1 power | JT1 voltage |
|---|---|---|---|---|
| 80 | 9.1 µW | 56 mV | 0.15 mW | 70 mV |
| 85 | 0.03 mW | 0.10 V | 0.49 mW | 0.13 V |
| 90 | 0.09 mW | 0.18 V | 1.5 mW | 0.22 V |
| 95 | 0.29 mW | 0.32 V | 4.9 mW | 0.40 V |
| 100 | 0.91 mW | 0.56 V | 15 mW | 0.70 V |
| 105 | 2.9 mW | 1.00 V | 49 mW | 1.25 V |
| Source | Price | Headroom, FT3 (350Ω) | Headroom, JT1 | Output impedance | Noise |
|---|---|---|---|---|---|
| JadeAudio JA11 | $20 | 4.8 dB | 2.9 dB | 0.5 Ω | 1.7 µV |
| FiiO KA11 | $29 | 13.2 dB | 11.1 dB | 0.7 Ω | 1.7 µV |
| FiiO BTR11 | $36 | 4.5 dB | 2.9 dB | 0.5 Ω | 8.0 µV |
Of the 280 sources here, 278 reach 100 dB on both. 70 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 70 is the JadeAudio JA11, at $20. It leaves 4.8 dB of headroom on the FT3 (350Ω) and 2.9 dB on the JT1, its output impedance is 0.5 Ω against a one-eighth limit of 43.75 Ω and 4.00 Ω, and its noise figure puts the hiss floor 30 dB and 32 dB below the 20 dB SPL this site treats as the point where a quiet room stops hiding it.
| Model | As printed | Tolerance | Standard |
|---|---|---|---|
| FT3 (350Ω) | 7Hz-40kHz | not printed | not printed |
| JT1 | 15Hz-30KHz | not printed | not printed |
FiiO prints 7Hz-40kHz for the FT3 (350Ω). FiiO's German distributor shop lists 15Hz-30KHz for the JT1. That figure stands on FiiO's German distributor shop, not on a document published by the maker.
Neither range has a tolerance printed beside it, so a wider range on one sheet is not deeper bass or more treble.
Not a measurement; maker by maker.
Both have a page of their own. In full: FiiO FT3 (350Ω) and FiiO JT1. Each figure on this page is labelled on those pages with where it came from, including the ones FiiO never published — what that maker publishes, counted.