FiiO KA15: power output and what it will drive

The FiiO KA15 is a USB dongle at $109. It delivers 180 mW into 32Ω and 19 mW into 300Ω, which ranks it 166 of 280 for raw power among the sources in this database.

Measured at 100 dB SPL it has comfortable headroom on 529 of the 567 dynamic and planar headphones catalogued here, enough but not generous on 35, only marginal on 2 and not enough power for 1. Adds a desktop mode that lifts output when plugged into a computer rather than a phone. Balanced 4.4 mm.

Specifications

What it actually puts out

TypeUSB dongle

Price$109

Power into 32 Ω180 mW

Power into 150 Ω38 mW

Power into 300 Ω19 mW

Power into 600 Ω9.5 mW

Output impedance0.8 Ω

Output noise1.7 µV

Comfortable headroom on 529 of 567 headphones (93%) · short of power on 1

Provenance

Where these numbers come from

The manufacturer publishes 290 mW into 16Ω, 180 mW into 32Ω, 19 mW into 300Ω. The rest of the table is worked out from those.

The balanced output is rated separately: 560 mW into 32Ω through the 4.4mm jack.

Derived rows hold output voltage steady, as an amplifier does (method).

Source: fiio.com, fiio.com.

Load	Power	Status	How it was arrived at
16 Ω	290 mW	Published	the manufacturer publishes this figure at this exact load
32 Ω	180 mW	Published	the manufacturer publishes this figure at this exact load
150 Ω	38 mW	Derived	worked out between two published loads, holding output voltage linear between them
300 Ω	19 mW	Published	the manufacturer publishes this figure at this exact load
600 Ω	9.5 mW	Derived	beyond the published loads, holding output voltage constant — which understates rather than flatters

Matching

Against 40 well-known headphones

Easiest to hardest to drive, with headroom at a 100 dB SPL peak.

Headphone	Impedance	Sensitivity	Needs	Headroom	Verdict
Shure SE846	9 Ω	114.0 dB/mW	0.04 mW	+36 dB	Comfortable audible hiss
64 Audio U12t	12.6 Ω	108.0 dB/mW	0.16 mW	+32 dB	Comfortable audible hiss
Shure SE215	17 Ω	107.0 dB/mW	0.20 mW	+31 dB	Comfortable faint hiss
Moondrop Aria	32 Ω	107.1 dB/mW	0.19 mW	+30 dB	Comfortable faint hiss
Audeze LCD-X 2021	20 Ω	103.0 dB/mW	0.50 mW	+27 dB	Comfortable faint hiss
Truthear Hexa	20.5 Ω	103.1 dB/mW	0.49 mW	+27 dB	Comfortable faint hiss
Sennheiser IE 200	18 Ω	101.6 dB/mW	0.69 mW	+26 dB	Comfortable faint hiss
Sony MDR-7506	63 Ω	106.0 dB/mW	0.25 mW	+26 dB	Comfortable faint hiss
Meze 99 Classics	32 Ω	103.0 dB/mW	0.50 mW	+26 dB	Comfortable faint hiss
Focal Clear MG	55 Ω	104.0 dB/mW	0.40 mW	+24 dB	Comfortable faint hiss
Philips SHP9500	32 Ω	101.0 dB	0.79 mW	+24 dB	Comfortable faint hiss
Focal Utopia	80 Ω	104.0 dB/mW	0.40 mW	+23 dB	Comfortable
Meze Empyrean	32 Ω	100.0 dB	1.0 mW	+23 dB	Comfortable
Campfire Audio Andromeda 2020	9 Ω	94.0 dB	4.0 mW	+16 dB	Comfortable
Etymotic ER2SE	15 Ω	96.0 dB/mW	2.5 mW	+20 dB	Comfortable
AKG K371	32 Ω	99.1 dB/mW	1.2 mW	+22 dB	Comfortable
Audio-Technica ATH-M50X	38 Ω	99.0 dB/mW	1.3 mW	+21 dB	Comfortable
Beyerdynamic DT 900 Pro X	48 Ω	100.0 dB/mW	1.0 mW	+21 dB	Comfortable
Audeze LCD-2 Classic	70 Ω	101.0 dB/mW	0.79 mW	+20 dB	Comfortable
Grado SR80x	38 Ω	98.0 dB/mW	1.6 mW	+20 dB	Comfortable
Sennheiser HD 560S	120 Ω	100.8 dB/mW	0.83 mW	+18 dB	Comfortable
HiFiMAN Edition XS	18 Ω	92.0 dB	6.3 mW	+16 dB	Comfortable
HiFiMAN Arya Stealth	32 Ω	94.0 dB	4.0 mW	+17 dB	Comfortable
Dan Clark Audio AEON 2 Closed	13 Ω	90.0 dB/mW	10 mW	+14 dB	Comfortable
Audeze LCD-5	14 Ω	90.0 dB/mW	10 mW	+14 dB	Comfortable
Beyerdynamic DT 1990 Pro (250Ω)	250 Ω	102.0 dB/mW	0.63 mW	+16 dB	Comfortable
HiFiMAN HE400se	25 Ω	91.0 dB	7.9 mW	+14 dB	Comfortable
HiFiMAN Sundara	32 Ω	92.0 dB	6.3 mW	+15 dB	Comfortable
Dan Clark Audio Stealth	23 Ω	90.0 dB/mW	10 mW	+13 dB	Comfortable
Fostex T50RP MK3	50 Ω	92.0 dB/mW	6.3 mW	+13 dB	Comfortable
AKG K702	62 Ω	92.9 dB/mW	5.1 mW	+13 dB	Comfortable
ZMF Verite Closed	300 Ω	99.0 dB/mW	1.3 mW	+12 dB	Comfortable
Sennheiser HD 650	300 Ω	97.8 dB/mW	1.7 mW	+11 dB	Comfortable
Sennheiser HD 800S	300 Ω	96.8 dB/mW	2.1 mW	+10 dB	Enough
Beyerdynamic DT 770 Pro (250Ω)	250 Ω	96.0 dB	2.5 mW	+10 dB	Enough
Audio-Technica ATH-R70X	470 Ω	98.0 dB/mW	1.6 mW	+9 dB	Enough
ZMF Atrium	300 Ω	96.0 dB/mW	2.5 mW	+9 dB	Enough
Abyss AB-1266 Phi TC	50 Ω	88.0 dB/mW	16 mW	+9 dB	Enough
Sennheiser HD 600	300 Ω	91.8 dB/mW	6.6 mW	+5 dB	Enough
HiFiMAN Susvara	60 Ω	83.0 dB	50 mW	+3 dB	Marginal

Noise

Will it hiss?

At 1.7 µV of output noise, here is where that noise lands in the five most revealing in-ears in the database.

This one hisses. With the most sensitive in-ears in the database its own noise lands around 26 dB SPL, which you will hear between tracks and in quiet passages.

In-ear	Impedance	Sensitivity	Hiss level
Simgot EA500	16 Ω	141.0 dB/V	26 dB SPL
Tanchjim EA FORCE	17 Ω	137.7 dB/V	22 dB SPL
Shure SE846	9 Ω	134.5 dB/V	19 dB SPL
Campfire Audio Clara	13.3 Ω	134.1 dB/V	19 dB SPL
64 Audio Fourte	10 Ω	134.0 dB/V	19 dB SPL

Damping

Output impedance and the one-eighth rule

At 0.8Ω output impedance, the one-eighth rule says this source suits headphones of 6.4Ω and above. 12 of the 567 models here fall below that. Most of them are multi-driver in-ears, and the mismatch tilts the frequency response audibly rather than subtly.

Check any pair.

Other specifications

What else the maker publishes

As published	FiiO KA15
DAC	CS43198 x2
Outputs	3.5 mm SE (shared with S/PDIF out), 4.4 mm balanced
Connection	USB-C
Formats	PCM 768 kHz/32-bit, DSD64/128/256; coaxial 384 kHz/32-bit
Weight	21 g
Dimensions	About 52 x 25 x 11 mm

Copied from the makers’ own pages: fiio.com/KA15_parameters. Battery life is the maker’s own test figure.

Cheaper

The cheapest thing here that does the same job

Source	Type	Price	Into 300 Ω	Output impedance	Output noise
FiiO KA11	USB dongle	$29	22 mW	0.7 Ω	1.7 µV

Of the 280 sources here, 1 do everything the FiiO KA15 does as a headphone output: reach 100 dB on every headphone it reaches, stay inside the one-eighth rule wherever it does and stay under the audible-hiss threshold wherever it does. The cheapest of them is the FiiO KA11 at $29, against this one’s $109 — $80 less.

This counts the headphone output only; inputs, converters, the volume control and the build are outside it.

Alternatives

Compared with its closest rivals: vs ddHiFi TC35Pro (Eye2) · vs ddHiFi TC44 Pro E2 · vs ddHiFi TC44Grip · vs DUNU DTC 480 · vs FiiO KA11 · vs FiiO KA13 · vs FiiO KA17 · vs FiiO KA3 · vs FiiO KA5 · vs FiiO SnowSky Tiny A · vs FiiO SnowSky Tiny B · vs Hidizs S9 Pro · vs Hidizs S9 Pro Plus · vs iBasso DC03 Pro · vs iBasso DC04 Pro · vs Onix Alpha XI1.

Compare any two or match your own headphones. Every FiiO source here.

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FiiO KA15: power output and what it will drive

What it actually puts out

Where these numbers come from

Against 40 well-known headphones

Will it hiss?

Output impedance and the one-eighth rule

What else the maker publishes

The cheapest thing here that does the same job

Other dongles at a similar price

Hidizs S9 Pro

Onix Alpha XI1

FiiO KA5

ddHiFi TC44 Pro E2

HiBy FC4

iBasso DC04 Pro