FiiO FT1 Pro: how much amplifier do you need?

The FiiO FT1 Pro is 20Ω with a sensitivity of 95.0 dB/mW, which is 112.0 dB/V. To reach 100 dB SPL — genuinely loud, louder than most people listen — it needs 3.2 mW, or 0.25 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, 257 have at least 10 dB of headroom and another 23 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

Impedance20 Ω
Sensitivity95.0 dB/mW
Sensitivity (voltage)112.0 dB/V
Power for 100 dB SPL3.2 mW
Voltage for 100 dB SPL0.25 V
TypeOver-ear
Easy to drive — anything will do it
All 280 sources at 100 dB SPL into 20Ω
Comfortable 257Enough 23Marginal 0Not enough 0
Cheapest portable source that does it
$9 · USB dongle · +8 dB headroom
Cheapest desktop amp with 10 dB to spare
$75 · desktop DAC/amp · +15 dB headroom

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

Where this sensitivity figure comes from

FiiO publishes this directly as 95 dB/mW (@1kHz), per milliwatt, so nothing was converted.

Source: fiio.com. How this data was built.

What is printed there, and what it is worth

As it is labelledAs printedToleranceStandard
Wide response range, hear every last detail7Hz-40kHznot printednot printed

FiiO prints 7Hz-40kHz for the FiiO FT1 Pro, under the heading “Wide response range, hear every last detail”. Source: fiio.com.

FiiO prints no specification table for this model at all; the range appears only as a marketing headline on the product page.

No tolerance is printed with it, so “7Hz-40kHz” says nothing about how loud this headphone actually is at 7 Hz.

Only what the maker printed; maker by maker.

Power, voltage and current by listening level

LevelWhat it isPowerVoltageCurrent
85 dB SPLquiet background listening0.10 mW45 mV2.2 mA
95 dB SPLnormal listening1.0 mW0.14 V7.1 mA
100 dB SPLloud listening3.2 mW0.25 V12.6 mA
105 dB SPLvery loud10 mW0.45 V22.4 mA
110 dB SPLpeaks on dynamic music32 mW0.80 V39.8 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 20Ω 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 20ΩHeadroomVerdict
FiiO SnowSky Tiny AUSB dongle$2240 mW+11 dBComfortable
FiiO SnowSky Tiny BUSB dongle$2254 mW+12 dBComfortable
FiiO KA11USB dongle$29224 mW+19 dBComfortable
Tanchjim Stargate IIUSB dongle$4078 mW+14 dBComfortable
ddHiFi TC35ALUSB dongle$46131 mW+16 dBComfortable
ddHiFi TC35AirUSB dongle$46131 mW+16 dBComfortable
Fosi Audio N3Bluetooth receiver$5086 mW+14 dBComfortable
Hidizs SD2USB dongle$5044 mW+11 dBComfortable
FiiO BTR13Bluetooth receiver$59110 mW+15 dBComfortable
iFi GO linkUSB dongle$5944 mW+11 dBComfortable
Kiwi Ears Allegro ProUSB dongle$6042 mW+11 dBComfortable
ddHiFi TC35Pro (Mountain2)USB dongle$6641 mW+11 dBComfortable
iBasso DC03 ProUSB dongle$6961 mW+13 dBComfortable
DUNU DTC 480USB dongle$7041 mW+11 dBComfortable
EPZ TP35 ProUSB dongle$7070 mW+13 dBComfortable

The three ways a source goes wrong

Hiss. At 112.0 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 20 dB SPL in these headphones — clearly audible in quiet passages. Check your own source.

Output impedance. At 20Ω these want a source output impedance below 2.50Ω 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 FT3 (32Ω) · vs FT3 (350Ω) · vs JT1.

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