Unfortunately, I'm not able to tell you what that opamp does for any use in my dac. It has a tube too. It has been replaced with an expensive one that should improve the sound. Then there are 2 capacitors that have been replaced with a gold silver version that costs quite a lot.
A DAC can be valuable due to the quality of the scheme and the final result obtained, i.e. a top sound, or it can be valuable due to the amount of precious metals contained and the price of the components used.
LME49720 and LM4562 are the same OA, as posted on here by a TI employee (they have identical performance when connected to an AP as well). It must be the screen-printing process that is causing this 'emasculation'.
Leaf spring sockets are unreliable after just a few insertions. Avoid them like the plague.
http://4.bp.blogspot.com/-7ruFnsbqfBg/TdFiulO8dUI/AAAAAAAAAME/Dj_MhVqM8Jw/s1600/1-Paradisea-Orig.jpg
This is a DAC full of snake oil.
The giant capacitors used there do not help at all, they do more harm by capturing more noise due to their very large dimensions. And the GND plane used without restrictions puts the noise from the digital area into the analog part.
I expect that no significant improvement will be obtained by changing the operational amplifier or the tube. Other changes could help significantly more, depending on how EMC polluted the environment is.
For example to put dimensional smaller capacitors in place of bigger ones, or to shield the entire PCB. But this will help in special if there are a noise EMC environment.
Even the use of a transparent plastic box to see the contents instead of the use of a metal box that would screen any disturbing external fields is a proof of snake oil.
Even the use of a transparent plastic box to see the contents instead of the use of a metal box that would screen any disturbing external fields is a proof of snake oil.