FiiO A3 Review – Amazing Value In A Portable Amp

by Sam-SoundGear.   Last Updated On September 13th, 2022.

FiiO was founded in 2007, and their first offerings were very low priced portable amplifiers. Today, FiiO has seen tremendous growth in the market, and this has seen them grow their product range to cater to the increasing demands of their buyers. Since the company’s inception, FiiO has been known to provide affordable, functional, well built, and most importantly, good sounding products. Today, I review the FiiO A3, also known as FiiO Kilimanjaro 2 (E11K). In this article, I break down the FiiO’s A3 design, sound, packaging and accessories, specs, and more. You can also check out our best headphone amps under $100.

FiiO A3 Specifications

Fiio A3 portable headphone amplifier review
Output Power: 270 mW (32 ohms/THD+N<1%)
450 mW (16 ohms/THD+N<1%)
Output Impedance: <0.2 ohms
MAX Output Voltage: 8.67 Vp-p
Headphone Drive Ability: 16-150 Ohms
Gain: -3.8 dB (GAIN=L)
11.7 dB (GAIN=H)
Input Sensitivity: 2.4 V (GAIN=L)
0.8 V (GAIN=H)
THD: 0.004% (1 kHz)
Frequency Response: 20-20 kHz
Audio Input/Output: 3.5 mm Jack
Battery Life: Approx. 16 hours run time on a 4-hours single charge
Dimensions: 3.58 x 2.2 x 0.51 in
Weight: 92 grams

See the FiiO A3 on



Looks and Build Quality

For any portable headphone amplifier to work well, it has to be unobtrusive. This means it has to be small and compact, roughly the size of a smartphone. The small size makes it easier to slide a portable amplifier into a pocket or bag with minimal effort. Luckily, with the FiiO A3, that is no problem.

The A3 is a rectangular block but features slightly beveled edges and curved somewhat on the sides and bottom. The shape resembles a drinking flask because of its rounded design around the edges and the volume potentiometer knob that is surrounded by two protruding metal pieces at the top of the amp. Though the curved design of the amp feels good in the hand, it is not well suited for stacking.

The build quality is great and features an aluminum alloy body casing that is smooth to the touch and weighs in at only 92g. Overall, the build is superb and has a feeling of indestructibility to it. The design is gorgeous though it would have been better to have one end flat for easy stacking.

FiiO A3 Kilimanjaro 2 (E11K)


The FiiO A3 comes with three main controls. One is the Alps potentiometer (Volume knob) that is nicely centered on top of the amp and nestled between two raised aluminum arms. This design makes it harder to destroy the amplifier if you accidentally drop it.

On the sides of the volume knob, the A3 features two flicker switches, one on each end. The two flicker switches are a low/high gain switch and a bass boost that also has two settings- on and off. When using the amp, there is no right or wrong way of using these switches as long as you like the sound of your music.

Once you have everything set up, you can try and experiment on the two settings to see which you prefer. Flipping the bass boost gives your music a stronger low-end presence. The default setting of the gain switch set at low gain and I would advise you to keep it that way unless your earphone/headphone is not loud enough at maximum volume, then you can set the switch to high gain. It is also worthy of knowing that most amplifiers perform worse when the gain is higher, and thus, it comes as no surprise that low gain is the default setting.

Inputs and Outputs

On the top side of the FiiO A3 amp, there is the Micro-USB charging port, a line-in port (see also line out vs. headphone out) and a headphone out port (3.5mm ports). Though the ports are straightforward to use, having them on the opposite side of the volume control is a little awkward and troublesome at times.

FiiO A3 Kilimanjaro 2 (E11K)

The 3.5mm ports are steady and after use seem they can handle pretty much anything. Though the 3.5mm is suitable, I think a 6.3mm jack would have opened up a lot more options. However, with the compact design of the A3, a larger jack might not have been possible, or this might be me being nitty-picky here.

Other than the ports, there is also a blue LED light that flashes blue when charging the amp and solid blue when the amp is on. Though the indicator works fine, I wish FiiO had used different colors to indicate different status. Like they could have used blinking red for charging, steady read for errors, steady green for charging, and steady blue when the amp is in use.

Battery Life and Portability

Though compact in size, one of the FiiO’s A3 best selling point to me would be the extensive battery life. The battery takes around four hours to charge and can provide about 16 hours of continuous playback. In testing, the FiiO A3 did not disappoint and delivered pretty accurate results compared to the 16-hour mark stated by FiiO, which was impressive. Admittedly, it is better, in terms of battery life, compared to other expensively priced FiiO portable headphone amps like the FiiO Q5, which offers just over eight hours of battery.

With 16-hours battery life, the FiiO A3 is very well suited to be a portable headphone amp. With this juice, you can listen to several albums all day without worrying running out of charge. However, if the amp runs out of charge and you are near a power source, you can charge the amp while still listening to your music.

FiiO A3 Kilimanjaro 2 (E11K)

Headphone Power

For output power, the FiiO A3 headphone amp uses the OPA1642 as a preamp, and for its power amp, it utilizes the AD8397. The given impedance range the FiiO A3 can drive effectively star from 16 ohms and up to 150 ohms.

In testing, while the FiiO recommends a range of 16-150 ohms, I tried to run the Sennheiser HD 600 with the A3, and the amp can drive the headphone though not as effective as it should be with higher output amps.

With the volume cranked up to a maximum, the headphone gives a range of 90dB. Flicking the gain switch to high would add another 15dB which makes it 105dB – which is more than you will ever need unless you fall into a special category. However, with that said, it is better to play it safe and use the FiiO A3 with a headphone or earphone that falls under their recommended impedance range. Luckily, most earphones and headphones fit into this range.


Audio Quality

The primary job of a headphone amp is to amplify the audio signal from a playback device with as low distortion as possible. If a headphone amplifier is doing its job correctly, then there should not be any adverse effects on the treble, mids, and bass. So, how does this amp sound and how much sound improvement can you expect over your in-built amp? Though there is no simple answer because it will depend on different aspects like the quality of the recording or the source, etc. However, one thing you can be sure of is the sound will always improve. Let’s see how the FiiO A3 faired on my tests.

Soundstage and Imaging

For the soundstage, imaging, and details, I would term the A3 as an average performer. However, When using the amp at low volumes, I experienced channel imbalances. This occurred mainly when the dial is set under 2. In its defense, I listen to music with moderate to high volumes depending on the type of headphone, ambient noise, etc. At normal volume, channel balance is quite good.

Neutrality and Clarity

Though the overall sound of the amp comes out as richer and fuller with more energy, the amplifier does an outstanding job in maintaining the sound signature of different headphones I tried. The overall sound of the amp I would categorize it slightly towards the warmer side.

High and Low gain

As earlier stated, it is better to use the amp in low gain whenever possible. I like the amp in low gain; however, the high gain option offers a decent boost in volume, which is great if you are driving demanding headphones. The extra power provided by the high gain option brings up more details, even in less-power hungry IEMs. The thing I like about the gain switch is that it makes a difference rather than being there as an afterthought.

Low-End (Bass) & Bass Boost

While most people might expect the bass boost in the FiiO A3 to change the quality of sound for the worst somewhat, the feature comes with several advantages that improve the overall output of sound. With the bass boost turned on, the music output seems to be more intimate, and soundstage seems to expand. The mids are fuller, and that to me is a good thing.

However, while the bass boost function might come as a blessing with some headphones, most bassy headphones suffer from distortion sounds in the mid and low bass region.

High-End (Treble) and Mids

The FiiO A3 is mostly a neutral amplifier. With the bass boost off, the treble comes out with good emphasis, detailed and well-spaced. The midrange remained true to the source. The separation between the midrange and treble was also good. With the bass boost engaged, the mids are fuller and an improved overall treble energy.

FiiO A3 Kilimanjaro 2 (E11K)

Packaging and Accessories

The FiiO E11K arrived in a white, a red and black colored box with a picture of the amp in front and some specs on the rear.

FiiO A3 Kilimanjaro 2 (E11K)

Other than the headphone amp, in the box it comes with, a USB to micro-USB charging cable, two rubber stacking bands, one (3.5mm-3.5mm) cable, six stick-on feet, and some warranty and instructions papers. The entire package includes all the related stuff you will need to use the FiiO A3 initially.

What we like:

  • Amazing Build quality
  • Long battery life good for portable use
  • Neutral

What we don’t:

  • Turning on/off the FiiO A3 when you have IEMs on produces a loud pop sound
  • Curved shape not suitable for stacking

Specs – Top FiiO A3 Competitors

FiiO A3 16 hours No 16-150 ohms 3.58 x 2.2 x 0.51 in
FiiO A5 13 hours Yes 16-300 ohms 4.88 x 2.6 x 0.59 in
FiiO E10K N/A Yes 16-150 ohms 3.11 x 0.83 x 1.93 in
FiiO Q1 >30 hours Yes 16-150 ohms 3.82 x 2.2 x 0.51 in
FiiO A1 13 hours No 16-100 ohms 1.6 x 1.6 x 0.4 in

BATT.* – Battery life
DAC* – Digital-to-Analog Converter
RHI** – Recommended Headphone Impedance

The Competition

FiiO A3 vs. A5

The FiiO A3 and the A5 are both very capable headphones. Comparing the design of both these two amps, the A3 is a little more compact than the FiiO A5. So, if the design of the headphone amp is a deciding factor, the FiiO A3 will be a better choice. If your budget allows it and the design of the headphone does not matter, the FiiO A5 is a great amp that is capable of driving most of the headphones in the market.

Other than the design and the budget, other factors you can check out before deciding between the Fiio A5 and the A3 include the battery life and the sound quality. With the battery life, the FiiO comes out as the winner; however, it is only by a small margin. The FiiO A5 manages to reach 12 hours on a 3-hours charge while the FiiO A3 hit the 16-hour mark with 4 hours of charge. In terms of the sound quality, both of these amps did a great of maintaining a neutral sound signature. The FiiO A3 is good at what it does, nice volume control, detailed sound, and clean power. The A5 delivers effortless audio that is clean and neutral even when using the gain switch.

To sum up, both of these amps are great. If you are using a headphone that rates an impedance of 16 to 150 ohms, then the A3 is the cheaper way to go. However, if you require more power or plan to upgrade your chain of headphones in the feature, the A5 is undoubtedly the way to go.

FiiO A3 vs. E10K USB DAC/AMP

The FiiO E10K comes at a very reasonable price. The FiiO A3 though cheaper, is a very worthy competitor of the E10K. First, the design of both headphones is very sturdy. However, I found the E10K better in terms of the positioning of the volume knob, and the output and input ports. The volume knob is also more prominent on the E10K compared to the A3. The FiiO E10K does feel lighter, but that is because the E10K is bus-powered compared to the FiiO A3, which comes with an internal battery.

Compared to the FiiO A3, the E10K is an excellent pick if you are looking at a reasonably priced entry-level AMP/DAC combo that sounds good. Unlike the A3, it offers you both a decent amp and a DAC to start with, and if in the future you decide to upgrade to a better amp, you can still use the FiiO E10K as a DAC because of its versatile connections.

FiiO A3 vs. Q1

The FiiO Q1 and the A3 are nearly identical headphone amps. However, I found the Q1 to be slightly better build that the A3. The tow headphone amps share a “flask” design, and both have the volume potentiometer on the top side. However, unlike the A3, the Q1’s volume knob is surrounded by a guard which protects it in case of a fall. The 3.5mm headphone output, which is gold plated is also on the top side, which is unlike the A3’s unusual port location.

Another thing I liked about the Q1 was the LED indicator. Unlike the A3 which blinks only blue, with the Q1; blue indicates power on/running on battery, red – charging, green – full charge, flashing red – low battery, purple – charging at the same the amp is on. The Q1 also features the bass and gain switches.

As for the sound, I found the FiiO Q1 has a neutral but slightly warm sound signature. Compared to the FiiO A3, as stated in this post, the Q1 is more neutral and overall has a better sound signature. The DAC (see also DAC under $1000) is also another plus of the Q1, which could also count as a deciding factor.

FiiO A3 vs. A1

At a retail price of less than $30, the FiiO A1 is one of the cheapest headphone amp offerings from FiiO. The next in line would be the K1 and the A3. At a price, the FiiO A1 is a solid unit that can take a beating. The front panel of the A1 features the on/off switch with integrated LED, a volume up and down buttons and a 3.5 mm gold plated headphone out port.

For a little compact headphone amp like the A1, the battery size is a big selling point. With a 1.5 hours charge, you can expect the A1 to give you up to 13 hours of charge. We a figure closer to this, 11.5 hours, which was good.

Tonally with the Bass EQ options not engaged, the A1 is balanced and does not introduce any noticeable audio differences from the source. The Bass EQ1, I found a to be an excellent addition, especially for light bass headphones. It boosts the low end and makes the overall sound fuller.

However, one gripe I have with the A1 is the noise levels, which makes it not suitable higher sensitive IEMs. Compared to the A1, the has lower distortion, longer battery life, but most importantly, it is more powerful. Other than the cost, the A3 comes out as a clear winner.

See the FiiO A3 on