FiiO A3 (E11K) Portable Headphone Amp

The FiiO A3 is a portable battery powered headphone amp released in 2014.

Just the Facts:

Physically, it is fairly small at 91.2 mm x 56 mm x 13 mm, and weighs 92 grams according to FiiO’s website. It comes in two colors; black and silver, and most of the outside of the unit is brushed aluminum with two plastic end caps on either side.

On one end of the unit, It has a 3.5mm input “Aux” jack along with another 3.5mm headphone (output) jack and a micro USB for power. Neither the headphone nor the Aux jack support in-line volume control, or microphones.

At the other end, there is a two-position gain switch, volume knob that doubles as a power switch, and a bass boost switch.

The battery is rated for 1400 mAh and, according to FiiO, should provide at least 16 hours of battery life. There is however, no indication of battery life that I can find other than the blue LED at the rear that will pulse while charging, and stay on when the device is turned on, or when it is fully charged.

Output power is rated at 270 mW @ 32 Ohms and 450 mW @ 16 Ohms. Output current is rated at 92.6 mA and Max output voltage is 8.67 Vp-p.

My Story and Opinion:

My need for a good amp arose when I bought the Sennheiser HD6XX (Gateway drug anyone?) and noticed that it sounded better when I gave it more power. I have a Hidizs Sonata HD that I was using and it sounded good on that, but then, when I got the FiiO BTR5, it sounded better, and then even better out of the balanced BTR5 output.

Originally, I decided to go with a Schiit Magni 3+ and the Grace SDAC from Drop. I figured the Magni would give me the best results with the HD6XX because it could put out tons of power. Since then, my Magni has developed a fuzziness in the output and has been rendered unusable. I thought that, while the Magni was out, this would be a good opportunity to experiment with different, more affordable options out there, so I hopped onto craigslist, searched “Headphone Amp” and the A3 popped up for $35.

To say I’m happy with my purchase is an understatement. While the A3 doesn’t have the same power rating as the Magni 3+, in my experience with it so far, it sounds just as good, if not maybe better due to the bass boost, which adds 3.5 dB @ 60 Hz giving some more body and punch to the HD6XX in some songs. The noise floor is very low, to the point where I can’t tell if it’s turned on without looking at the volume knob or the LED on the back.

I’ve only tried it with the 6XX, KPH30i and Portapros so far, but I plan on testing it with everything I can get my hands on in the future.

My only real complaint with it so far is the fact that I don’t feel completely comfortable putting it into my pocket. I’m afraid that the knob will twist clockwise and potentially blow my eardrums out. I’m considering modeling a 3d-printable guard that can fit over-top of it to prevent that from happening.

All things considered, I’m putting some serious thought into whether or not I want to keep the Magni 3+ now. Ultimately, the decision will be made when I get it back from repair and A/B test with the A3, but so far, for $35 used or $60 on amazon, I think this is a hell of a choice for those looking to get started.


Excellent review @Panzer_Applehusky. I am a big fan of FiiO gear. They offer good value.