This soundcard ( HT Omega Claro Halo Soundcard ) has four JRC4580 Opamps.
The first two combines the polarity signals from the AK4396 DAC, then passes the combined signals to the other two opamps for amplification to the headphone and RCA outputs.
Even though the manual says that you can change the first two opamps only, the effect is very minimal because the second pass to the latter two IC opamps somehow neutralizes the Burson discrete Opamps.
You only get the full Burson Opamp effect when you change all four IC opamps to the Burson discrete Opamps!!