Pros: Really quite small. Build quality is pretty good. Nice black paint and overall presentation. Packaging it came with was very nice. Came with the required cables to charge and connect. Provides a noticeable boost in volume. Can't really comment on sound quality though.

Cons: I took it off my mp3 player as I couldn't be bothered carrying something bulky.

Other Thoughts: Really nice thing to have. The rechargable li-ion internal battery is much better than the AAA batteries required for the hold Fiio Amp.

Bottomline: Try it out to see if it improves the sound quality of your mp3 player. It's pretty cheap so you won't really be losing out. You can always resell it in your home country for about the same price.

Pros: Comes with a belt clip, which is very useful for attaching to apparel while running/jogging. Also comes with 2 3.5mm cords, to use between the amplifier and the mp3 player.
Greatly increases sound quality, especially for more expensive in-ear headphones and other hi-fi gear.

Cons: Requires charging every 30+ hours.
Also causes more tangling between wires, and the audio will hiss if the amplifier is set too loud.

Other Thoughts: Some of the words are scratching off the front side, but that's alright, it has no effect on the sound quality.

Bottomline: Great for music listening, especially on the go.

Pros: - very portable;
- good looking;
- good build and sound quality for the price
- much more better than the E3;
- increase bass with low bass headphone;
- pretty good cables too, seems to have gold plated 3.5mm plugs.

Cons: - a bit of hiss with low impedance headphone;
- battery will drain off even when connected to the usb;
- the bass boost is not very effective, it just seems to "muddy" the bass sound.

Other Thoughts:

Bottomline: a must-have a for anyone who don't have a portable amplifier.
just buy and try it. it's cheap, you won't lose a fortune.
reccomended!!

Pros: - It's much much much cheaper than normal portable headphone amplifiers.
- It's portable
- Nice battery life
- Volume control
- Nice clip to fit on your clothes
- Two modes of amplification: flat or with bass boost.
- Nice packaged and with good instructions
- Its pretty
- It gives more body to the sound, feeling the basses (not being bass boost), making the sound more realistic.
- Much smaller than other audiphile portable amps. This is the tiniest amp!

Cons: - Obviously sound quality is not awesome. Audiophile portable amps of >90$ sounds much better but well, price difference is huge, what did you except? this is one very nice from its price.
- You can't have it plugged via USB and feed from it, not using the battery to mantain its life longer. When it's on, it uses the battery, being connected via USB or not. Would be neccesary to fix it and be able feed only from USB.

Other Thoughts: If you don't have any headphone amplifier, you MUST buy this. You will see how a headphone amplifier corrects the signal properly to be well processed by your headphones-drivers.
Perfect too to leave it in work or to use to make sport.
As the amplifier it is, it helps much more when weaker is your signal. With an ipod it makes the sound 20% better. With a realtek sound-card, it makes the sound 100% better.

Bottomline: Just buy it. Its cheap. Try it. Later post about how good its for its price. FiiO amplifiers are very respected!