Apple USB-C dongle (EU): power output and what it will drive

The Apple USB-C dongle (EU) is a USB dongle at $9. It delivers 15 mW into 32Ω and 2.0 mW into 300Ω, which ranks it 53 of 53 for raw power among the sources in this database.

Measured at 100 dB SPL it has comfortable headroom on 128 of the 310 dynamic and planar headphones catalogued here, enough but not generous on 103, only marginal on 56 and not enough power for 23. The European version is volume-limited in firmware and noticeably weaker than the US one.

What it actually puts out

TypeUsb dongle
Price$9
Power into 32 Ω15 mW
Power into 150 Ω4.0 mW
Power into 300 Ω2.0 mW
Power into 600 Ω1.0 mW
Output impedance1 Ω
Output noise6 µV
Comfortable headroom on 128 of 310 headphones (41%) · short of power on 23

Against 41 well-known headphones

Ordered from easiest to hardest to drive. Headroom is measured at 100 dB SPL, which is louder than almost anyone listens — a small negative number means the source still plays loud, just without reserve for peaks.

These figures come from each manufacturer's own sensitivity rating. A handful of planars — the HiFiMAN Susvara and HE-6se and the Abyss AB-1266 in particular — are widely reported to need far more than their published sensitivity implies, so treat a bare pass on those as optimistic rather than settled.

HeadphoneImpedancedB/mWNeedsHeadroomVerdict
Shure SE8469 Ω114.00.04 mW+20 dBComfortable audible hiss
64 Audio U12t13 Ω108.00.16 mW+16 dBComfortable audible hiss
Shure SE21517 Ω107.00.20 mW+16 dBComfortable audible hiss
Moondrop Aria32 Ω107.00.20 mW+19 dBComfortable audible hiss
Sennheiser IE 20018 Ω104.00.40 mW+13 dBComfortable audible hiss
Audeze LCD-X 202120 Ω103.00.50 mW+13 dBComfortable audible hiss
Sennheiser HD 25 (1-II)70 Ω108.00.16 mW+17 dBComfortable audible hiss
Sony MDR-750663 Ω106.00.25 mW+15 dBComfortable audible hiss
Meze 99 Classics32 Ω103.00.50 mW+15 dBComfortable audible hiss
Focal Clear MG55 Ω104.00.40 mW+14 dBComfortable audible hiss
Philips SHP950032 Ω101.00.79 mW+13 dBComfortable audible hiss
Truthear Hexa21 Ω99.01.3 mW+9 dBEnough audible hiss
Focal Utopia80 Ω104.00.40 mW+12 dBComfortable audible hiss
Meze Empyrean32 Ω100.01.0 mW+12 dBComfortable audible hiss
Campfire Audio Andromeda 20209 Ω94.04.0 mW+0 dBMarginal audible hiss
Etymotic ER2SE15 Ω96.02.5 mW+4 dBEnough faint hiss
AKG K37132 Ω99.01.3 mW+11 dBComfortable faint hiss
Grado SR80x32 Ω99.01.3 mW+11 dBComfortable faint hiss
Audio-Technica ATH-M50X38 Ω99.01.3 mW+10 dBComfortable faint hiss
Beyerdynamic DT 900 Pro X48 Ω100.01.0 mW+10 dBComfortable faint hiss
Audeze LCD-2 Classic70 Ω101.00.79 mW+10 dBEnough faint hiss
Dan Clark Audio AEON 2 Closed13 Ω92.06.3 mW-0 dBNot enough faint hiss
Sennheiser HD 560S120 Ω101.00.79 mW+8 dBEnough faint hiss
HiFiMAN Edition XS18 Ω92.06.3 mW+1 dBMarginal faint hiss
HiFiMAN Arya Stealth32 Ω94.04.0 mW+6 dBEnough faint hiss
Audeze LCD-514 Ω90.010 mW-2 dBNot enough faint hiss
HiFiMAN Sundara37 Ω94.04.0 mW+5 dBEnough faint hiss
Beyerdynamic DT 1990 Pro (250Ω)250 Ω102.00.63 mW+6 dBEnough faint hiss
HiFiMAN HE400se32 Ω91.07.9 mW+3 dBMarginal faint hiss
AKG K70262 Ω93.05.0 mW+2 dBMarginal faint hiss
Fostex T50RP MK350 Ω92.06.3 mW+2 dBMarginal faint hiss
ZMF Verite Closed300 Ω99.01.3 mW+2 dBMarginal
Dan Clark Audio Stealth23 Ω87.020 mW-3 dBNot enough
Sennheiser HD 650300 Ω98.01.6 mW+1 dBMarginal
ZMF Atrium300 Ω98.01.6 mW+1 dBMarginal
Audio-Technica ATH-R70X470 Ω99.01.3 mW+0 dBMarginal
Sennheiser HD 600300 Ω97.02.0 mW+0 dBMarginal
Sennheiser HD 800S300 Ω97.02.0 mW+0 dBMarginal
Beyerdynamic DT 770 Pro (250Ω)250 Ω96.02.5 mW-0 dBNot enough
Abyss AB-1266 Phi TC42 Ω88.016 mW-1 dBNot enough
HiFiMAN Susvara60 Ω83.050 mW-8 dBNot enough

Will it hiss?

At 6 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 30 dB SPL, which you will hear between tracks and in quiet passages.

In-earImpedanceSensitivityHiss level
Shure SE8469 Ω134.5 dB/V30 dB SPL
Moondrop Quarks16 Ω131.0 dB/V27 dB SPL
64 Audio U4s12 Ω127.2 dB/V23 dB SPL
64 Audio U6t12 Ω127.2 dB/V23 dB SPL
Audeze LCD-i320 Ω127.0 dB/V23 dB SPL

Output impedance and the one-eighth rule

At 1Ω output impedance this source satisfies the one-eighth rule with every headphone in the database, down to the 8Ω in-ears. Nothing here will have its frequency response shaped by the source.

The rule is a rule of thumb, not physics: a source impedance below one eighth of the headphone's keeps the interaction under about 1 dB. The checker works it out for any pair.

Other dongles at a similar price

Or put any two side by side in the source comparison tool, or run your own headphones through the amplifier matcher.