[DeeKay10]

I thought the EQ method would be the holy grail, so I turned it on and lowered everything to -6dB. The result: The music sounded muffled. -_-
Choosing a simply flat EQ has a much more subtle impact, but it's still there and like everyone else here that spent a total of $500 on two aluminum bricks, I want no compromises.
Whatever they did to the EQ on the X5, it evidently sucks:

[line-out to line-in recordings of a 60 seconds sine sweep]
 
Now, regarding the imbalance issues which I'm the only one that seems to be having: I suspect I'm experiencing it because I use a very powerful line-out feed to the amp (either the X5 or the PC's on-board chip). So before I start working on a replacement (sending it back to the ebay retailer...), could anyone please do these steps, exactly as described, and report?
1. Plug the amp either to the X5's line-out (with EQ off) or your computer's headphone jack.
2. If plugged in to the computer, raise the volume to 100%.
3. Switch to high gain on the E12A.
4. Plug your IEMs in, turn on the amp and move back the dial to the lowest volume without turning it off (should be easy enough).
5. Put on some music and very gently, increase the volume.
6. Are you experiencing any channel imbalance at the beginning of the spin?

 

[audioxxx]

Yeah, I am a little disappointed to see the distortion introduced into the EQ, and I can also hear its cleaner with EQ off.
I hope this can be fixed in a firmware.
 
I have tested my e12a sample  with a X5 in high gain on the e12a, and their is the imbalance you speak of in those conditions, but I don't  use high gain on tiny volumes with sensitive iem's(so your safe)  and its hardly noticeable in low gain, again at volumes I would not use on this amp, I don't think you have a faulty amp, just a hot input signal. (on the sony a15 dap (line out) its spot on no imbalance with full range of volume. (but doesn't sound as good as the LO on the X5,EQ off)

 

[kino lau]

Fiio explained their reasoning for the db drop when using the EQ, though I can't recall where I read it. My experience so far is that Fiio produces some hi quality products, to the extent that I often visit their site to see what I can buy next...lol. EQ the LO?  BLASPHEMY!!!

 

[audioxxx]

Fiio does this dropping the output of to prevent digital clipping, but as you can see on the graph, there's plenty of noise being introduced with the Equaliser on.

 

[nmatheis]

Fiio does this dropping the output of to prevent digital clipping, but as you can see on the graph, there's plenty of noise being introduced with the Equaliser on.

Any comparison with other DAP's EQs? I know X5 EQ sounds better than DX90 EQ, which also ducks the gain to prevent clipping. When I max out all sliders in DX90 to bring volume back to normal non-EQ levels, it sounds like I'm listening through a tin can. I don't get this with X5. iPod/iPhone EQ also sounds sounds bad compared with X5. What I'm getting at is - yes the graphs look bad, but graphs are one thing and hearing is another.

 

[audioxxx]

Any comparison with other DAP's EQs? I know X5 EQ sounds better than DX90 EQ, which also ducks the gain to prevent clipping. When I max out all sliders in DX90 to bring volume back to normal non-EQ levels, it sounds like I'm listening through a tin can. I don't get this with X5. iPod/iPhone EQ also sounds sounds bad compared with X5. What I'm getting at is - yes the graphs look bad, but graphs are one thing and hearing is another.

I'm finding the EQ on the Sony dap a lot more responsive, and doesn't seem muffle up the sound like the x5.
But the dac isn't as good, and it can not produce micro detail like the X5, which I use in the evening, In silence.

 

[DeeKay10]

  [...]
I have tested my e12a sample  with a X5 in high gain on the e12a, and their is the imbalance you speak of in those conditions, but I don't  use high gain on tiny volumes with sensitive iem's(so your safe)  and its hardly noticeable in low gain, again at volumes I would not use on this amp, I don't think you have a faulty amp, just a hot input signal. (on the sony a15 dap (line out) its spot on no imbalance with full range of volume. (but doesn't sound as good as the LO on the X5,EQ off)

 
Ah, so it is a production issue. I agree about high gain not being relevant to (vast majority of) IEMs. Unfortunately, when paired with the X5, even with the gain set to low, spinning the dial enough to fix the channel imbalance is too loud for home/office/train listening.
I find this extremely absurd and frustrating, with Fiio systematically publishing on their website pictures of their DACs paired with their amps, plugged to some high-end IEMs (using their own cables), with zero functional correlation between the lot. Normally, when you buy multiple products from the same company, you'd expect them to work together flawlessly.
 
It was mentioned earlier in this thread that you can't please everybody and that some IEMs are not suitable for the E12A. This is complete nonsense. The amp is targeted towards IEM users and as such should support all of their types, from power-hungry dynamic drivers to super sensitive armatures. It is my impression from posts in this thread that most of the amp's owners don't go beyond the 11:00 o'clock mark on low gain, which means Fiio had at least 50%-12dB more room for tweaking. To me this looks like a really big skip on the Quality Assurance step on the way to the production line. They couldn't have possibly missed the fact that popular IEMs like the Shure SE535 are on the verge of exploding when hitting the 10:00 o'clock mark on the dial.
 
To sum it up before I start working on a proper review, the E12A is my 4th (and last) Fiio product. By now, I'm familiar enough with the company's products and can characterize them with the following saying: "Superb internals wrapped in a cheap Chinese package". Each Fiio product I owned fulfilled its purpose (sound quality) and had a major flaw on the long run.
E06 amplifier: Good sound quality; bad clip that seldom falls apart when on the move.
RC-SE1 cable: Noticeable sound quality improvement; extremely microphonic when not sitting still.
X5 DAP: Superb sound quality and dual MicroSD support; fatiguing amp (for some), bad software and bad scrolling wheel.
E12A amplifier: Superb sound quality and bass boost; too powerful to be used on the go when fed from some line-outs.

 

[Mr Trev]

Can't exactly remember where I've read it, but seems that some channel imbalance at low volumes is inevitable with analogue volume control. I'm sure it was mentioned on some of the threads here, you can probably search it out. Doesn't seem to be manufacturer specific, happens to all devices to some degree.

 

[DeeKay10]

I Googled it and you're right.
Unfortunately, it still leaves us with the overpowered output. =|

 

[snarkyd]

Sadly, I find the X3 LO to be much too high as well. Using the e12A on low gain I can barely get the dial past 9 using 846s.

 

[Stereodude]

Can you buy or make a cable that has a voltage divider in it?  That would knock down the signal amplitude.

 

[Voyst]

Hi everyone, 
 
How would you rank X5 vs X1+E12A ?
Thanks !

 

[3ternalDr4gon]

What headphones/earphones are you using? If you need the extra juice (high impedance) then X1 + E12A might be the way to go

 

[Voyst]

Thanks for your reply.

I use havi B3 p1 and grado SR225i so I think both X1+amp and X5 would drive them quite well. It is more on a matter of SQ ...

 

[3ternalDr4gon]

Oh ok, well I don't think you'll find too many people that own both since the X1 came out after the X5. The X5 sounds really good , but you have to account for micro SD card costs as well (I'm assuming you're asking this question mainly due to budget reasons).
 
If you only care about sound quality and are willing to sacrifice a screen for it, check out the Shozy Alien thread:
 
http://www.head-fi.org/t/733349/a-little-about-the-shozy-alien 
 
On sale on massdrop for 1 more day for $140. Retail is $200 I believe, I paid $160 to get it sooner than massdrops shipping date of Jan 12 from null audio
 
There are claims that the Alien sounds better than X5 + E12 as well as the AK120. I just got mine today, but my initial reaction upon early usage agrees with those claims.