FiiO X3 mod - AD8397 to AD8620
post-9561577
Thread Starter
Post #1 of 263

ClieOS

IEM Reviewer Extraordinaire
Joined
May 11, 2004
Messages
19,633
Reaction score
8,688
Location
Middle of Johor, Malaysia
Joined
May 11, 2004
Location
Middle of Johor, Malaysia
Posts
19,633
Likes
8,688
Website
InEarMatters.net
Someone asked me to post the mod, so I thought I'll make it into an independent thread instead of putting it somewhere inside a X3 discussion.
 
Basically the mod is as simple as it gets: open the X3 up, disconnect the battery, desolder the AD8397, solder in the AD8620, and put everything back.
 
The goal is to remove the warmness from the AD8397 and replace it with something that sounds more neutral. AD8620 has been one of my personal favourite on portable amp, so it is my first choice. Another candidate will be OPA2209. Both will never be able to match the current output of AD8397 - however, realistically speaking, both already have more than enough output for typical headphone anyway (* = won't be suitable for low impedance, low sensitivity, hard-to-drive 'phone). From experience, OPA2209 probably won't sound as neutral as AD8620, but it should be a good middle point between AD8620 and AD8397 - as alternative for those who find AD8620 too bright to their taste. Another side benefit of the mod will be a likely extended battery life, since both opamps draw less power than AD8397.
 

AD8620 on top of X3, just for size reference.
 

Be careful on the hold switch (just next to the silver battery). You need to see how it comes off so you will know how to put it back.
 

Pull the battery connector out before any mod.
 

The stock AD8397, just under the yet-to-solder AD8620. Do check the orientation carefully before desoldering / soldering!
 

Done. Put everything back together now. If X3 shows some error on headphone connection, that means you have weak solder joint and you should retouch them with the iron.
 
Note: Desoldering SMT is far harder than soldering. If this is your first SMT project, I seriously think you should practice on other thing first. The way I do is pretty much destructive to the original opamp, as I heated and pry a leg at a time, so they either break off or bend out of shape completely. I am sure there are far more elegant and least destructive way of doing it, just search youtube and you should find quite a few of the tutorials. I am however too lazy to bother, as I have some spare AD8397 around and don't need to save this one.
 
The result is as I have expected, a much more neutral and detail presentation. I can almost compare it to the X3's line-out + O2. Well worth the effort as this finally brings out the transparency of the player than is somewhat hindered by the AD8397's warmness. Now the new X3 is a proper AK100 killer.
 
post-9561606
Post #2 of 263

Levanter

Headphoneus Supremus
Joined
Jun 14, 2013
Messages
2,625
Reaction score
369
Joined
Jun 14, 2013
Posts
2,625
Likes
369
nice!
can i send you my X3 to mod too? =D
 
     Share This Post       
post-9561616
Post #3 of 263

AmberOzL

Headphoneus Supremus
Joined
Dec 18, 2012
Messages
4,150
Reaction score
614
Joined
Dec 18, 2012
Posts
4,150
Likes
614
Nicely done. I am not good on that skills I would probably ruin if I try something like that. Too bad for me.
 
X3 is already an AK100 killer. Now it even kills it faster 

 
     Share This Post       
post-9562133
Post #4 of 263

RAFA

Headphoneus Supremus
Joined
Jan 31, 2009
Messages
1,678
Reaction score
105
Joined
Jan 31, 2009
Posts
1,678
Likes
105
ClieOs you are awesome.
 
     Share This Post       
post-9563415
Post #5 of 263

ClieOS

IEM Reviewer Extraordinaire
Joined
May 11, 2004
Messages
19,633
Reaction score
8,688
Location
Middle of Johor, Malaysia
Joined
May 11, 2004
Location
Middle of Johor, Malaysia
Posts
19,633
Likes
8,688
Website
InEarMatters.net
Thanks.
 
There is actually another opamp inside, the AD8692 on the DAC output stage. Upgrading it will further improve headphone-out as well as line-out. I am thinking whether LM4562 will be suitable. But AD8692 is nice enough that I think I will keep it for now, maybe reserves as a future DIY project.
 
     Share This Post       
post-9563564
Post #6 of 263

pekingduck

Headphoneus Supremus
Joined
May 16, 2009
Messages
2,281
Reaction score
163
Joined
May 16, 2009
Posts
2,281
Likes
163
I also findthat the sound is not as detailed as I would like.... wish I had some DIY skills... 

 
     Share This Post       
post-9563588
Post #8 of 263

thegrobe

1000+ Head-Fier
Joined
Sep 30, 2012
Messages
1,088
Reaction score
85
Joined
Sep 30, 2012
Posts
1,088
Likes
85
Wow this is awesome!

Thanks for posting this. I have been avidly following the x3 development, and will certainly buy one as soon as it is available in the US. The one thing that is a bit of a worry to me is the "warm" sound signature. I really would prefer something more neutral.

I have the soldering skills, this mod is a 100% no-brainer. Now just awaiting x3 availability.

Brilliant! Thanks!
 
     Share This Post       
post-9563806
Post #9 of 263

RAFA

Headphoneus Supremus
Joined
Jan 31, 2009
Messages
1,678
Reaction score
105
Joined
Jan 31, 2009
Posts
1,678
Likes
105
Thanks.

There is actually another opamp inside, the AD8692 on the DAC output stage. Upgrading it will further improve headphone-out as well as line-out. I am thinking whether LM4562 will be suitable. But AD8692 is nice enough that I think I will keep it for now, maybe reserves as a future DIY project.

As soon as I get one X3,I will try at least the swap to ad8620, though I like warm sound.

Wonder how much diffeeence there will be when changing the dac output stage.

Just a few questions.

Is the DAC-output stage = the DAC buffer?

Is it a single ic?

Thanks rafa :)
 
     Share This Post       
post-9564537
Post #10 of 263

ClieOS

IEM Reviewer Extraordinaire
Joined
May 11, 2004
Messages
19,633
Reaction score
8,688
Location
Middle of Johor, Malaysia
Joined
May 11, 2004
Location
Middle of Johor, Malaysia
Posts
19,633
Likes
8,688
Website
InEarMatters.net
Quote:
Is the DAC-output stage = the DAC buffer?

Is it a single ic?
 
It is a dual channel opamp. Yes and no on the buffer - yes that it does act like a buffer; but no that it isn't there as buffer. WM8740 only outputs differential signal (positive+negative for both left and right) so you need an opamp to convert it to single ended signal (left/right/ground).
 
     Share This Post       
post-9565283
Post #11 of 263

RAFA

Headphoneus Supremus
Joined
Jan 31, 2009
Messages
1,678
Reaction score
105
Joined
Jan 31, 2009
Posts
1,678
Likes
105
Quote:
 
It is a dual channel opamp. Yes and no on the buffer - yes that it does act like a buffer; but no that it isn't there as buffer. WM8740 only outputs differential signal (positive+negative for both left and right) so you need an opamp to convert it to single ended signal (left/right/ground).
 
Thanks for the info. I can prepare myself a little.
 
     Share This Post       
post-9565358
Post #12 of 263

ClieOS

IEM Reviewer Extraordinaire
Joined
May 11, 2004
Messages
19,633
Reaction score
8,688
Location
Middle of Johor, Malaysia
Joined
May 11, 2004
Location
Middle of Johor, Malaysia
Posts
19,633
Likes
8,688
Website
InEarMatters.net
I abandon the idea of LM4562 for AD8692. Need to find a rail-to-rail, low power, low noise opamp for the job, and LM4562 isn't rail-to-rail. The search continues...
 
     Share This Post       
post-9565371
Post #13 of 263

Armaegis

Modern Modder Man of Manitoba
HTML... uphill, both ways!
Joined
Oct 18, 2009
Messages
12,187
Reaction score
1,133
Joined
Oct 18, 2009
Posts
12,187
Likes
1,133
Heh, so now who's going to be adventurous and try to bend and fit this in with two OPA627's?

 
     Share This Post       
post-9565373
Post #14 of 263

AmberOzL

Headphoneus Supremus
Joined
Dec 18, 2012
Messages
4,150
Reaction score
614
Joined
Dec 18, 2012
Posts
4,150
Likes
614
Quote:
I abandon the idea of LM4562 for AD8692. Need to find a rail-to-rail, low power, low noise opamp for the job, and LM4562 isn't rail-to-rail. The search continues...
ClieOS, at your signature it says almost time to leave with very small letters. Does it mean soon you will close head-fi account? I hope not 

 
     Share This Post       

Users Who Are Viewing This Thread (Users: 0, Guests: 1)

Top