FiiO KA11 vs Kiwi Ears Allegro Mini

Short answer

More power: the FiiO KA11, with 200 mW into 32 Ω; the Kiwi Ears Allegro Mini has 30 mW. The FiiO KA11 drives 19 headphones to 100 dB that the Kiwi Ears Allegro Mini cannot (Beyerdynamic DT 880 Edition (600Ω), Beyerdynamic DT 990 Edition (600Ω), HiFiMAN HE-6se V2, 16 more).
Quieter with sensitive IEMs: the FiiO KA11. 16 headphones stay below audible hiss on it but not on the Kiwi Ears Allegro Mini (64 Audio Fourte, Campfire Audio Andromeda 10, Campfire Audio Andromeda 2023, 13 more).
Price: the FiiO KA11 costs $5 more; what that buys on these numbers is set out further down, under What the price difference buys.

Both are dongles, $29 against $24.

The FiiO KA11 reaches 100 dB on 566 of the 567 models here, the Kiwi Ears Allegro Mini on 547.

Every published figure, next to each other

Specification	FiiO KA11	Kiwi Ears Allegro Mini
Power into 32Ω	200 mW	30 mW
Power into 150Ω	43 mW	6.4 mW
Power into 300Ω	22 mW	3.2 mW
Power into 600Ω	11 mW	1.6 mW
Output impedance	0.7 Ω	not published
Output noise	1.7 µV	3.0 µV
Price	$29	$24
Headphones it reaches 100 dB on out of 567	566	547

Not published means the maker leaves it out, so that axis cannot be compared.

Where each power figure comes from

Load	FiiO KA11	Kiwi Ears Allegro Mini
32 Ω	Published	Published
150 Ω	Derived	Derived
300 Ω	Published	Derived
600 Ω	Derived	Derived

Both makers publish a power rating. FiiO KA11 publishes at 32 Ω and at 300 Ω; Kiwi Ears Allegro Mini at 32 Ω. The other rows are worked out from those.

So the two columns are not equally firm row by row: at 300 Ω only the FiiO KA11 figure is the maker’s own. On those rows the derived number is the one to doubt first.

What the labels mean.

The headphones that tell them apart

19 headphones reach 100 dB on the FiiO KA11 but not on the Kiwi Ears Allegro Mini — Beyerdynamic DT 880 Edition (600Ω), Beyerdynamic DT 990 Edition (600Ω), HiFiMAN HE-6se V2, 16 more.

16 headphones stay below the audible-hiss threshold on the FiiO KA11 but cross it on the Kiwi Ears Allegro Mini (64 Audio Fourte, Campfire Audio Andromeda 10, Campfire Audio Andromeda 2023, 13 more).

547 of the 567 models here reach 100 dB on both.

Headroom and hiss on 8 models, both sources

Headroom is at a 100 dB SPL peak.

The widest gap on the list is the Shure SE846: FiiO KA11 has +35 dB of headroom there against +23 dB. 12 dB is about 16 times the power, which matters for peaks rather than for how loud the music sits.

Hiss below about 20 dB SPL is inaudible in a quiet room.

Headphone	Impedance	Needs	FiiO KA11 headroom	Kiwi Ears Allegro Mini headroom	FiiO KA11 hiss	Kiwi Ears Allegro Mini hiss
Shure SE846	9 Ω	0.04 mW	+35 dB	+23 dB	19 dB	24 dB
Campfire Audio Andromeda 2020	9 Ω	4.0 mW	+15 dB	+3 dB	-1 dB	4 dB
Audeze LCD-2 Classic	70 Ω	0.79 mW	+21 dB	+12 dB	-3 dB	2 dB
Beyerdynamic DT 1990 Pro (250Ω)	250 Ω	0.63 mW	+16 dB	+8 dB	-7 dB	-2 dB
HiFiMAN HE400se	25 Ω	7.9 mW	+14 dB	+5 dB	-8 dB	-3 dB
Audio-Technica ATH-R70X	470 Ω	1.6 mW	+9 dB	+1 dB	-14 dB	-9 dB
Sennheiser HD 600	300 Ω	6.6 mW	+5 dB	-3 dB	-18 dB	-13 dB
HiFiMAN Susvara	60 Ω	50 mW	+3 dB	-5 dB	-20 dB	-15 dB

The gap in dollars, against the gap in numbers

The FiiO KA11 costs $5 more than the Kiwi Ears Allegro Mini. Out of the 567 models here, that difference buys 19 more models driven to 100 dB and 16 more models kept below the audible-hiss threshold.

Nothing runs the other way: there is no axis here on which the cheaper of the two does better.

Only published figures count here; blank axes are counted separately.