On my version of SY-DAP1002 I rotated the volume knob such the last led in the volume ring is blinking by mistake. The amp does not switch off itself anymore. I don't notice any variation in the music is playing.
Hi Toku,
I have opened my DAP1002 (REV 1.1) and the OP amp is NE5532. One thing I forgot to mention is that I only listened with Bluetooth input.
DAP1002 (REV 1.1) - inside picture.