FiiO X3 mod - AD8397 to AD8620
Oct 10, 2013 at 3:27 PM Post #121 of 263
  You must have access to oscilloscopes then? I'm sure you can design a test amplifier circuit where you can measure the impact a wire can have on the entire design. Have the oscilloscope point between the two outputs and see for yourself if the wire did any damage for your circuit.  My experiences with this is that there is no impact of introducing a wire whatsoever to an amplifier circuit. 

 
I do have access to oscilloscope but prefer to use my ears to judge sq differences. 
 
I'm sure that in simple wire breadboard design extra 30-40cm of metal wire doesn't make huge difference, but again this is a little more complicated design. 
 
Oct 10, 2013 at 4:34 PM Post #122 of 263
I first tried the opamps in the iBasso D4 and auditioned every opamp. I also tried the AD8397 in the D4 to hear if the opamp sounded similar in the iBasso D4 as it did in the X3. Since it did sound very similar I concluded the other way around would also apply. So I suggest you to try the opamps in a swappable config and find out AD8397 shares the same sound with that setup as it does inside the X3. iBasso D4 has the same DAC-chip as X3.
 
Oct 10, 2013 at 5:07 PM Post #123 of 263
   
I do have access to oscilloscope but prefer to use my ears to judge sq differences. 
 
I'm sure that in simple wire breadboard design extra 30-40cm of metal wire doesn't make huge difference, but again this is a little more complicated design. 

if there is no noise found in signal readings, then what makes you think the human ear can detect signal noise better? It's not like we have the mental capacity to calculate SNR with just our eardrums! 
You have the tools in place as you have said. Take the advice of the other member and use the wire (if it's possible to do so)  just to be safe 
L3000.gif
. Please do tell us of your findings. 
 
Oct 10, 2013 at 5:54 PM Post #124 of 263
  if there is no noise found in signal readings, then what makes you think the human ear can detect signal noise better? It's not like we have the mental capacity to calculate SNR with just our eardrums! 
You have the tools in place as you have said. Take the advice of the other member and use the wire (if it's possible to do so)  just to be safe 
L3000.gif
. Please do tell us of your findings. 

 
You are almost right, but you know that one's opinion about SQ is very subjective and vulnerable to many factors. Seeing wires hanging could affect my view. But I'll give it a go (I'll have the AD8397 out anyway). 
I'll use the IC's that I already have in BrownDog dip adaptors and use short wires connected to dip socket on piece of protoboard. Much less soldering , results would be same.
 
Oct 10, 2013 at 6:22 PM Post #125 of 263
   
You are almost right, but you know that one's opinion about SQ is very subjective and vulnerable to many factors. Seeing wires hanging could affect my view. But I'll give it a go (I'll have the AD8397 out anyway). 
I'll use the IC's that I already have in BrownDog dip adaptors and use short wires connected to dip socket on piece of protoboard. Much less soldering , results would be same.

take pictures and post them here! 
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Oct 10, 2013 at 6:27 PM Post #126 of 263
Once I'll have a day to spare will do. Wouldn't like to be left without DAP.

EDIT: 16/10/13

Decided to mod the DAP anyway without test phase. The choice was between 3 chips anyway - AD8599, AD8620 and AD8066. I liked all of them in my JDS cMoy but here decided to solder the 8066 op-amp.
I like it, I like it a lot. The sound lost some warmness but also a bit of muddiness. There is a lot more bass but it's punchy bass, I actually had to take 2 points down on bass. Listening some classic Jarre now and new dubstep tracks. With dubstep I feel like someone is massaging my ears, with Jarre I can almost hear him touching the keyboard :wink:
 
Oct 18, 2013 at 4:54 PM Post #128 of 263
The sound is definitely more clear, but there is also more bass. It's not not muddy bass though, feels faster, sounds better, just had to drop it 2 points down.
Overall after week of listening I'm glad I did it.
 
Oct 18, 2013 at 7:19 PM Post #132 of 263
Once I'll have a day to spare will do. Wouldn't like to be left without DAP.

EDIT: 16/10/13

Decided to mod the DAP anyway without test phase. The choice was between 3 chips anyway - AD8599, AD8620 and AD8066. I liked all of them in my JDS cMoy but here decided to solder the 8066 op-amp.
I like it, I like it a lot. The sound lost some warmness but also a bit of muddiness. There is a lot more bass but it's punchy bass, I actually had to take 2 points down on bass. Listening some classic Jarre now and new dubstep tracks. With dubstep I feel like someone is massaging my ears, with Jarre I can almost hear him touching the keyboard
wink.gif

Thanks for the update! I'm personally too scared to mod the X3 since I have poor soldering skills. :frowning2: 
 
Glad you are enjoying the DAP! 
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Oct 22, 2013 at 3:41 PM Post #133 of 263
During last 2 days i did some more testing. First I decided to swap the second op-amp (DAC output one) and I found how if hugely affects the sound! First tried LM7332 - it was awful, slow and muddy, but I didn't had many more options. The ic works on +5V (single supply) and it's r2r. Today decided to move the AD8066 from the headphone output in place of AD8692 and solder AD8599 in place where AD8397. 
 
Loving the combination so far.
 

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