Fiio E18

Advantages: Good sound quality, nice body and controls.
The main function is performed with a bang.
Also, the device easily connects to windows and osx.

Disadvantages: There is no screen from radio signals: the sound can be understood that the phone is looking for a network or is about to be a call. A special tin when you go in the elevator, and several people have phones looking for a network. All of these signals are in the headphones.
Also, on my copy, the “next track” button is the “previous track”, and vice versa. Although it is even more convenient :)
It is impossible to use a headset when connecting this amplifier: the data from the microphone on the cable is not sent to the phone, the caller’s voice is not sent to the headphones. Perhaps these are the features of working with my phone.
Work as a powerbank is also sad: the amplifier can only give 700mA from its 3000mA.

Comment: I use together with LG G4. When using a device with a connected amplifier, android often crumbles and prepares a lot of error reports. Also, the screen of the phone sometimes becomes excessively bright and colorless (it looks like a Windows desktop with a quake minimized 3). It happens that the next track is included much earlier than the current one ends. There are left touch screen.
Documentation is hard to find, but you can: https://www.dropbox.com/s/n80b24ywdgyg43e/E18%20User%20Manual.pdf?dl=0


UPD: switched to samsung s8 +, and audio output via fiio works only with USB3 -> USB2 adapter. USB3 -> microUSB does not connect fiio as audio output.

Advantages: Great device at a great price. Absolutely pure full-bodied sound, with decent bass and clear high, there is an ardent middle. There is a battery, it works with all phones and tablets with which it was possible to try - and this is in the quality of a DAC, and not just an amplifier. Ability to work from the PS as a DAC.

Disadvantages: For me, not a lot of sound is dry, not enough volume.

Comment: A completely bug-free device, the sound may not like it, if only compared with more expensive devices. Certainly much better than the built-in sound, do not forget to use high-end headphones (speakers) and you will be satisfied.

Advantages: 1. Power is sufficient.
2. Own noise is low.
3. I did not notice any harmonic distortion.
4. Solid design - will pay attention to you.
5. The gain switch on the low frequency (it would be possible to integrate more functionality).

Disadvantages: 1. Analog potentiometer. When adjusting the volume wheezing sound. This is unacceptable for an expensive device. As if he had not yet poured in, how the graphite layers fell off the Soviet potentiometers.
2. Interference. Can be very strong, for example, when the surrounding phones catch the network.
3. Capricious. It may not be installed or intercepted control on USB OTG in bundles "smartphone - Fiio" (something with a non-standard descriptor of the USB port at Fiio). I once lost the connection because of the phone nearby, catching the network. Well, the ears drove.
four.The absence of wires for the bundle "smartphone - USB OTG - Fiio". The wire with active plugs ("OTG", "A") "Micro USB OTG - Micro USB OTG" will have to be soldered by yourself. Convenient corner plugs "Micro USB" is even harder to find (saw 30cm on AliExpress).
5. The sharp edges of the hull and the thin black coating on aluminum are not practical - they lose their appearance quickly.
6. A bundle of smartphone and amplifier via USB is not designed for mobile operation, it is easy to damage - there are no sides to protect the ports from kink.

Comment: Think before you buy. Using such bundles in the mobile version is very inconvenient, besides, you will have to look for the "Micro USB" plugs for soldering and solder the wires yourself, here is a link to the photo-instruction of my soldered wire https://yadi.sk/i/ahevwZjWuSn2e

Advantages: I was surprised by an unusually clear and beautiful sound! I don’t know how they did it, but the amplifier seems to add drama to any lyrical melody, although it can sound much simpler from a simple player - and this is just an amplifier from a linear output of any player / phone! Also impressive is the detail and high resolution of the sound.

Disadvantages: This amplifier suddenly had its own specific view on the reproduction of aggressive guitar distortion, which didn’t quite coincide with my personal preferences. It is somehow designed for more melodic sound harmonies, which suddenly stands out from the music. There are no complaints to other genres, it even captures somehow. The power of the amplifier (suddenly) does not exceed the power of music players like iPod classic and Creative ZEN Vision. That is, it is concrete to use oak Sennheiser HD series headphones to shake this amplifier better than players do, it will not work.

Comment: In general, what I expected from this amplifier - I got it, but in order for the shades of taste and color to coincide - of course you need to listen to this before buying. I advise you to listen with your headphones. Oh, by the way about the headphones. Do not expect miracles from bad headphones, do not fantasize that some magical device will suddenly transform the sound of crappy plugs. But from the good headphones, this amplifier can squeeze what you did not expect when used with other playback devices.

Advantages: - Sound quality
- Mobility
- Ability to work as an external battery
- Analog potentiometer

Disadvantages: - Very moody

Comment: Plays very much even a great scene. Tested on Senheiser HD 280 Pro, Audio-Technica ATH-M50x, Beyerdynamic DT 880 PRO. Everything pulls, pulls buyers, but of course not as good as previous models. On the ATH-M50x sibilance is not observed, and the headphones are rather capricious to the sound source.

Problems begin when trying to use as DAC, when used with FooBar, you must explicitly set the buffer to no more than 1s, otherwise there will be no sound. My Galaxy Note 3 (5.0) doesn’t want to work with it normally, constant sound interruptions, every 1-5 seconds, if someone calls or receives a notification message while listening to music, it will lose some screeching sound, terrible .

No shielding problems were detected, no left-handed interference exists at all.

Advantages: Sound.
Reliability
Well assembled.

Disadvantages: Normally it functions only with telephones declared on the company's website. These phones are few.

Comment: I use it as a sound card to a laptop. If you connect to the amplifier through the headphone output, it works like a norm. DAC and provide (quite bearable). The result pleased. No complaints.

Advantages: Multi layer scene

Disadvantages: There is no instruction in Russian

Comment: I must say that the sound out of the box at first somewhat disappointed. I used to listen to records of at least SACD quality. This quality transmits such music, which occurred when recording in the studio, without astronomical treble and ultra-low drums. The sound initially seemed littered tops with loose bottoms. On the medium could not immediately identify nylon strings or steel.After 20 hours of warm-up, a new sound came together with SAMSUNG NOTE2 and AKG702. In 2 words: stationary TEAC in your pocket. Naturally, if the recording quality is appropriate, since even wav 24/96 sometimes sounds awful because of the lack of knowledge of people that it is impossible to format a SACD on a computer at home without changing the frequency response.