The service manual does not mention the maker of the DAC chip. My Onkyo states AKM DAC right on the box, my Pioneer Elite mentions it uses Wolfson DAC's in reviews, Sony's DAC's are not mentioned in any review or literature of the DA5400ES, or the 2002 Sony STR-DA7ES i also own for that matter. Maybe they just use their own in house designed DAC, who knows.\n\n\nMost importantly, how does the AVR sound? The Sony ES models I've had were quite good. This might be one earlier than the ones I had.