Jeffs1I actually tried to plug this O2+SDAC with a pair of JBL 305P speakers through the RCA from the back of the dac. It worked until i had games running. It started to make these buzzing sound as soon as i started the game.
Jeffs1Check this thread: https://www.massdrop.com/buy/massdrop-o2-sdac-dac-amp/talk/2091631
tl;dr - to quote OpasTanti: "My particular unit came with wrong gain configuration (2.5X and 6.5X* instead of 1X and 3.3X listed on the product page) and other units might be affected by this as well (at least from what I've noticed on a teardown from Reddit).
*O2's input stage will overload when set to high gain of 6.5X with SDAC's output at max, which may cause the sound to become distorted but it won't harm the O2."