[jpvanirsel]

Which one should i get?

 

[PurpleAngel]

The A3 has a more powerful headphone amplifier, but does not have DAC function.
Q1 has more useful features.
 
Might help to know all the uses you have planned for the device.

 

[jpvanirsel]

I am Going to use it with my phone and denon ah mm400

 

[Gonomon]

You should probably get Q1. Because of the circuits of your phone you are likely to hear hissing noises if you only connect amp to your phone.

 

[west0ne]

I have the Q1 and it sounds OK to me and gets loud enough to listen comfortably (K702) but I certainly don't claim to be an aficionado. One thing to watch is the Q1 isn't specifically designed for use with phones although it's design and size would suggest otherwise. It works fine with my S7 straight into the OTG, it also worked fine on my Moto G into the OTG, with my S5 it needed a USB hub in between the phone OTG and the Q1(didn't need to be powered).
 
I also have the iBasso D14 which has more power and works with my S7 & S5 but not the Moto G so getting a match between phone and DAC is a consideration. 

 

[Ambiance]

I have the q1 since a while back and have started to regret not getting the a3 or e12, it's extremely good when connected via USB both from computer and phone, the problem is that I don't get at all as good amplifying when connected with 3,5mm via the phone. The difference in power here is enormous... And the phone will just let me use it once, if disconnected I have to turn the phone off and then turn it on again, otherwise it won't find the q1. This is extremely frustrating when it won't power the dt990 pro 250 ohm to louder volumes via 3,5 than if I plug directly into the phone. It's slightly louder maybe but if would do a Pepsi challenge it really wouldn't be easy to tell if it's the fiio or if it's the phone jack. I have the Xperia z3. I think it can be well worth having this information if you don't know how it will work with your phone and if the phone is the device you intend to primarily listen from.

Personally I think I will need to get the a3 or possibly the e12 because of this problem. I don't think that I have a bad sample either because I remember reading some review here on head fi and this user also reported that you will get significantly more power when connected via USB.

Oh, I might add that I use USB audio player pro and with the Lenovo tab 2 it works like a charm! The problem here is with Xperia z3. With computer it's no problems either. I just wonder why it's so starved on power with minijack connection? This is truly a disappointment, but otherwise I'm happy with it, though a bit irritated as I seem to have to get yet another amplifier now as the phone was what I primarily intended to use this with.

Ah, I saw now which headphone you intend to use it with and for the denon ah mm400 it should be fine either way. That one is much easier to drive than the dt990 250ohm and the m50x's for example it manages just fine with the minijack also, but I guess if you go for the q1 you do because of the dac also so try to make sure it will work with your phone before getting it.