[ClieOS]

  Why is no one talking about OPA1642?
I've been using OPA1641 on my Leckerton UHA-6S (MK1), they're fantastic.
 
I have the 1642 on order, will attack my X3 with a soldering iron as soon as it arrives.

 
Seems nice overall, based on spec. I am however a little worry about its output impedance.

 

[ClieOS]

 
The output current of OPA1611 is greater than +/-45mA (from Fig.27 on the datasheet), plenty for a whole bunch of headphones.

 
The worry is on output impedance and the possibility of oscillation since it is not designed to drive big capacitance load.

 

[recephasan]

   
Seems nice overall, based on spec. I am however a little worry about its output impedance.

OPA1642 is doing fine in my X3 with my HD600, RS-1, Ortofon E-Q5. What headphones do you suppose it would have a difficult time driving?

 

[ClieOS]

  OPA1642 is doing fine in my X3 with my HD600, RS-1, Ortofon E-Q5. What headphones do you suppose it would have a difficult time driving?

 
Multi-driver headphones / IEM, especially those with wonky impedance curve. It is not about how demanding the load is, but whether the uneven output impedance might introduce excessive coloration to the headphone or not.

 

[Mmet]

Just ordered the AD8066 as it is rail to rail op amp .... i've red online that its sound DC coupled is different and have more low bass ..... any way i wish that it will be less warm , more detailed than AD8397 

 

[Mmet]

if i want to mod the DAC section with wm8741 (after installing ad8066) ... is it will work fine ? and will the change in sound quality will be significant ? ... i know it will affect the battery life ... but i don't care about that


 

 

[ClieOS]

  if i want to mod the DAC section with wm8741 (after installing ad8066) ... is it will work fine ? and will the change in sound quality will be significant ? ... i know it will affect the battery life ... but i don't care about that


 

 
There are probably something extra you need to do to the WM8741 for it to work in X3, as that chip needs to be set to hardware mode, I think. I don't really have any detail on it but I think I read it somewhere before, so search around.

 

[SergBill]

Good result whith LT1886 (phone amp) and ADA4898-2 (preamp, bipolar power, which will remove the capacitors from the signal circuit). and strengthened the power of chips using capacitors Nichicon SW 220uF (5 pieces)
If anyone is interested, I can put photos with explanations.
Sorry for my bad English

 

[Mmet]

I am very very interested but I already purchased the ad8066 for the amp section only .... When it arrives we will see

 

[SergBill]

AD8066 Single-Supply, AD8397 - Bipolar, this is probably a small problem

 

[Mmet]

  AD8066 Single-Supply, AD8397 - Bipolar, this is probably a small problem

BTW .... i don't know what is that means 

 .... but some guy here made that mod and he was pleased with it

 

[Mmet]

oh DAMN !!! those things are sooo small !!

 

[Mmet]

FWIW .... my first smd work is done successfully by replacing AD8397 with AD8066 

 and it was a very dangerous move as i don't have any experience with SMD work before and with my poor eyes it was more difficult
 
seems clearer now ... much clearer ... with a nice sound signature and nicer bass than stock 
 
thanks to @ClieOS for that awesome thread and very helpful mod
and thanks to @wakibaki for his advise about cutting the original opamp's legs as he described
 
 the mod is great ... better clarity and details .. more defined sound stage ... no more warm sound but with beautiful bass ... and with the same power (  same volume level i used before with the stock opamp ) but now i listen to lower volume levels as the clarity of sound and neutrality no  need to increase the volume to enjoy details ......  
 
about the heating issue ... the player before can go truly hot ( it is normal i know ) but a bit disturbing too ..... now and after day and half it is cold .... no heat at all ... except for one time it was sightly warm ... just slightly and that is all 
 
about the battery life i don't know yet the exact time it takes from 100 % full until shut down 
but i will update soon

 

[fullcircling]

^^are you on the new 3.0 firmware? if so, no hickups with it?

 

[ClieOS]

  ^^are you on the new 3.0 firmware? if so, no hickups with it?

 
Firmware won't interfere with what opamp you uses.