[Markoj]

Since I didn't find anything about moding 2nd version of Fiio X3 I started I new thread so I can share my findings and mod tips.
 
As I wasn't satisfied with sound quality on stock player I modified it to some extent.
 
The stock Chinese tantalum caps are "very very" bad quality. Just measure one and you will throw it away immediately ( ESR is 2-3 times higher then some other quality tantalum ) capacitance is also lower than stated ( 47uF measured as 37uF or so).
 
The complete mod will include changing all capacitors and resistors with quality ones( the cheapest ones that you can buy on Mouser or Farnel is "high" quality compared to this )
 
I have changed to date this:
 
1. Changed the DAC supply tantalum caps with 100uF.
2. Bypassed and removed stock tantalum(10uF) and 2 ceramic capacitors that were on the signal line past first OPamp. ( there is no DC at the output )
3. Changed the power supply caps near 2nd OPamp and headphone amp with 100uF.
 
Note that all OPamps (2 of them) and Headphone amp are on the same power rail, and 2 capacitors still need changing ( near lower Opamp )
 
Lineout I haven't touched since I don't use it.
 
Sound difference ? Much cleaner, detailed, more energy in bass and more low freq.
  

 

[DrumsFillo]

Amazing work!!!

Is this difficult to do, or with a welder I can approach to change the capacitors and resistors??

 

[Markoj]

Tnx,
I'm using smd soldering tweezers, so it's not a problem. I guess you can use hot air too, or whatever you are comfortable soldering smd stuff.

 

[DrumsFillo]

Thanks a lot!

I'll try to find all these components and then do the work!!!

 

[mandello]

Could you please tell me wich screwdriver and other tools i've to use to open it?!?!

 

[muhatidus]

Does it would drain the battery faster, or just the same with the stock?

 

[Markoj]

Does it would drain the battery faster, or just the same with the stock?

Same as stock.

 

[moped2000]

Hi Markoj,
great idea! I would love to try it, but I don't know which capacitors I have to change. Could you mark them in a photo?
Many thanks in advance!

 

[AzmiAN]

Hi Markoj,
great idea! I would love to try it, but I don't know which capacitors I have to change. Could you mark them in a photo?
Many thanks in advance!

Yeah some photo might help

 

[badrooster]

I'd love to see some pics of this process as well, I'm gonna have to open up my Fiio X3 soon and just getting a peek at the guts and process could be super useful!

 

[Markoj]

Sry guys for late reply. Here are the few pictures.

On 1st picture or where you see hearamp opamp and buffer opamp you can see there is one cap added ( because there was none...) at supply leg ( 0.1uF )
On the opamp on the right same story... There is a massive gain by doing this only.
On 2nd picture were the DAC is, another manufacturing error is placement of the 0.1uF cap on digital supply for DAC. This small cap should go near the chip, not after the big one... ( you can see the empty spot )
Caps for DAC supply is ceramic ones 16V 80-100uF ( much better ripple suppression then tantalums ) great for power filtering at this stage.

Output caps are bypassed.

About sound difference after this mod, the difference is like night and day, no comparison.

 

[moped2000]

Thank you very much for the photos!! I made a photo with your changes marked.
https://ibb.co/jrMyDy8
Is this correct? And I did not find the changes at the DAC. Where is the empty spot and where did you add something?
How would you sort the mods in order of effectivity?
In your first post, you also wrote something about replacing some caps, which you did not mention in your last post. Does this mean the mods in your last post are more important?
Thanks so much!

 

[Markoj]

Hi moped2000,
Yes that is partialy correct.At DAC all caps for supply where changed with ceramic(bigger capacity- better ripple suppression then tantal - measured with scope )
On your photo ( empty spot ) that is digital supply. The goal here is to put 0.1uF cap near DAC in front of the bigger 20uF (or what value it is) and not behind it ( that is design flaw )
In the latest post/photos are the lates mods.

Adding missing 0.1 caps at headphone amp and opamp improved measurements alot.

 

[Markoj]

Also when you bypass output tantalum caps, you have to remove 2 small ceramic caps above and below it.