FiiO X3 mod - AD8397 to AD8620
Nov 1, 2013 at 11:32 AM Post #151 of 263
  I just checked and my iBasso D4 uses AD8616 as DAC output opamp. It works single supply 2.7V to 5V and is a CMOS rail-to-rail opamp, just like the AD8692.
AD8066 is a FET opamp.
iBasso D4 has dual DACs though.
You should be carefull since clipping can occur at the DAC output when you swap the opamp. I have no idea about the signal that the DAC puts out, safest is to ask Fiio directly.

I took your advice and ordered some AD8656 and ADA4841-2. Both were mentioned in iBasso D1 thread, the latter was recomended on (I used google translate).
So another day another swap :wink:
I've soldered ADA4841-2 as DAC output IC and LMH6643 as headphone amp (as per and D1 threads). I've listened the DAP for literaly 5 minutes before going back to work, so no opinion as yet, apart from the facts it works. I'm going to leave ADA in place and do some rolling on the headphone output - LMH6643, LME49720, AD8599 and AD8620.
EDIT: after 2 hours of constant listening to my favourites tracks decided to keep the DAP like it is now, with ADA4841-2 and LMH6643. The sound blew my mind, the level of details, clarity and dynamics is just right. No more rolling for now :wink:
Nov 7, 2013 at 7:42 PM Post #152 of 263
​​Dear friends,

Could anyone send me HiRes photo of Fiio X3 board with removed (unsolder) Wm8740 DAC chip
which would have been clearly visible line contacts under the chip?

I casually damaged a few contacts under the chip

​and now it's difficult to restore them​ without a photo :frowning2:
I will be very grateful to you for your help!!!!
Thank you!!

my email:
Nov 11, 2013 at 5:45 AM Post #153 of 263
modded it with the muses 8820 just now, and it works :D
unfortunately i don't have another x3 with me so i can't really test whether it was for the better or worst :x
it stills sounds great to me though.
the 2 caps at the side was PITA and not soldering anything for months was making things very hard.
Nov 23, 2013 at 9:14 PM Post #154 of 263
sorry, I am not very clear with this mod, just give me answer for this silly question.
I thought AD8397 is an opamp with gain (amplifier), and after ask to my google, I found wolfson wm8740 follow by lowpass filter, so which one in this X3 design? 
If I have to mod this X3, I would go to replace the lowpass filter opamp, rather than amplifier opamp.    


Dec 6, 2013 at 4:38 AM Post #156 of 263
I mean, differential to single ended opamp. 
Dec 9, 2013 at 3:40 AM Post #158 of 263
  just replaced the AD8397 to AD8620, but the sound change is not found.
headphone DT 770 Pro 80 ohm
perhaps only the amount of bass was slightly less

i would say that it does exactly what it should then?
Dec 26, 2013 at 3:02 PM Post #162 of 263
I havent read the whole tread, but where can I get the OPA2229? The only thing I can find that comes close to the Number is OPA228 or 2227?
I would like some more clarity and maybe less bass, but dont like anything to become sharp or harsh! :)
Jan 4, 2014 at 8:49 AM Post #164 of 263
I really want to thank you so much.
I ordered an O2 amp from Epiphany acoustics that arrived on New Years's Eve. I bought the connecting cable yesterday and hooked it up and it has already improved my system. The Fiio X3 sounded good already; the new Fiio cables on my Shure SE215s made a big difference, but this amp has truly transformed my system from the first time I plugged it in.
Thanks for your great advice. It saved me a lot of time and made a huge difference for very little money
Thanks again
Jan 4, 2014 at 9:00 AM Post #165 of 263



Sorry, I made a mistake in replying to an earlier answer you gave to me.


I wish to credit you with the invaluable information you gave me (Previous post)


Thank you so much. You are my new God. Can I marry you and bear your children?




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