FiiO FT3 (32Ω): how much amplifier do you need?

The FiiO FT3 (32Ω) is 32Ω with a sensitivity of 95.1 dB/mW, which is 110.0 dB/V. To reach 100 dB SPL — genuinely loud, louder than most people listen — it needs 3.1 mW, or 0.31 V across the drivers.

That puts it in the easy category. A phone, a laptop headphone jack or the cheapest USB dongle will drive it to painful levels. Of the 280 sources in the database, 259 have at least 10 dB of headroom and another 21 have enough. The cheapest portable source that does the job is the Apple USB-C dongle (US) at $9.

The two numbers that decide everything

Impedance32 Ω
Sensitivity95.1 dB/mW
Sensitivity (voltage)110.0 dB/V
Power for 100 dB SPL3.1 mW
Voltage for 100 dB SPL0.31 V
TypeOver-ear
Easy to drive — anything will do it
All 280 sources at 100 dB SPL into 32Ω
Comfortable 259Enough 21Marginal 0Not enough 0
Cheapest portable source that does it
$9 · USB dongle · +10 dB headroom
Cheapest desktop amp with 10 dB to spare
$75 · desktop DAC/amp · +17 dB headroom

Sensitivity here is in dB per milliwatt. Why the unit matters.

Where this sensitivity figure comes from

FiiO, as the shop reproduces it, publishes this as 110 dB/V (1 Vrms @ 1 kHz) — a figure per volt, not per milliwatt. At 32Ω the two differ by 14.9 dB, so the 95.1 dB/mW above is that published number converted, not a different measurement.

This is the conversion that online calculators skip. Quote the per-volt number as if it were per-milliwatt and this headphone looks 15 dB easier to drive than it is — which is roughly the difference between a dongle being enough and not being enough.

One caveat about the source. Almost everything in this database comes from a document the maker published. This entry does not: the figures above stand on someone else's product page — FiiO's German distributor shop — and not on any page FiiO publishes. Shops usually copy the factory table faithfully and this one may well be exact — but a shop can also carry an old revision, and if FiiO changes the number there is nothing here that would notice. It is the weakest provenance on this site, which is why it is written on the page rather than left in a footnote.

FiiO's own FT3 page covers only the 350Ω version — it prints “Impedance: 350Ω” and “Sensitivity: 105dB (1Vrms)@1kHz” and never mentions the 32Ω variant. FiiO's launch announcement describes that variant but publishes no specification table for it. The fiio.com address on this entry is context, not the source of the numbers: those come from FiiO's German distributor shop.

Source: fiio-shop.de, fiio.com. How this data was built.

What is printed there, and what it is worth

FiiO prints no frequency range for the FiiO FT3 (32Ω) at all. Source: fiio.com.

FiiO has one FT3 page and it is the 350 Ω version: it prints "Frequency response: 7Hz-40kHz" beside "Impedance: 350Ω". No page of their own covers the 32 Ω FT3, so there is no range printed for this variant — which is not the same as FiiO printing nothing for the FT3.

Only what the maker printed; maker by maker.

Power, voltage and current by listening level

LevelWhat it isPowerVoltageCurrent
85 dB SPLquiet background listening0.10 mW56 mV1.7 mA
95 dB SPLnormal listening0.98 mW0.18 V5.5 mA
100 dB SPLloud listening3.1 mW0.31 V9.8 mA
105 dB SPLvery loud9.8 mW0.56 V17.5 mA
110 dB SPLpeaks on dynamic music31 mW0.99 V31.1 mA

Most people listen between 75 and 85 dB; the 100 dB row leaves room for peaks.

The cheapest sources that drive them with room to spare

The 15 cheapest of the 280 sources here that reach 100 dB SPL into 32Ω with at least 10 dB of headroom and no known hiss or output-impedance problem with these headphones. All 280 sources, judged for these headphones.

SourceTypePricePower into 32ΩHeadroomVerdict
FiiO SnowSky Tiny AUSB dongle$2234 mW+10 dBComfortable
FiiO SnowSky Tiny BUSB dongle$2234 mW+10 dBComfortable
FiiO KA11USB dongle$29200 mW+18 dBComfortable
Tanchjim Stargate IIUSB dongle$4075 mW+14 dBComfortable
ddHiFi TC35ALUSB dongle$46210 mW+18 dBComfortable
ddHiFi TC35AirUSB dongle$46210 mW+18 dBComfortable
Fosi Audio N3Bluetooth receiver$50138 mW+16 dBComfortable
Hidizs SD2USB dongle$5070 mW+14 dBComfortable
FiiO BTR13Bluetooth receiver$59100 mW+15 dBComfortable
iFi GO linkUSB dongle$5970 mW+14 dBComfortable
Kiwi Ears Allegro ProUSB dongle$6068 mW+13 dBComfortable
ddHiFi TC35Pro (Mountain2)USB dongle$6665 mW+13 dBComfortable
iBasso DC03 ProUSB dongle$6998 mW+15 dBComfortable
DUNU DTC 480USB dongle$7065 mW+13 dBComfortable
EPZ TP35 ProUSB dongle$70112 mW+16 dBComfortable

The three ways a source goes wrong

Hiss. At 110.0 dB/V these are sensitive enough to reveal a source's own noise floor. The noisiest source in the database, the Schiit Mjolnir 3, would put its hiss at roughly 18 dB SPL in these headphones — clearly audible in quiet passages. Check your own source.

Output impedance. At 32Ω these want a source output impedance below 4.00Ω to satisfy the one-eighth rule; 35 of the 192 sources that publish one miss it. Check yours here.

Similar headphones

Compared with its stablemates: vs FT1 · vs FT1 Pro · vs FT3 (350Ω) · vs JT1.

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