Gain stage question (I guess) - (probably MPC live related)

hey gang - hope someone can help:
I’m going from my mixer (mackie 1202vlz) into the apollo twin and am monitoring through the apollo. the sound is beautiful and clear as… dead silent and hardly any noise when having the mixer output on unity (to be sure to test, I dialed down all the aux returns)… from the Apollo out I’m going into the MPC live so I can sample my complete chain (OTO boum between mixer and Apollo - disabled for testing). when playing back the samples I am hearing a quite audible noise floor, the sample is roughly as loud as the mixer output - but noisy.

I am aware that i am going through AD/DA twice: AD into apollo, DA apollo out, AD MPC in, DA MPC out…
here’s my question:
could the ADDA causing the noise floor? the MPC manual doesn’t really help and the rec gain doesn’t seem to distort … even if MPC rec gain is dialed down I can hear the same noise when playing back the samples. the connection to the gain out on the MPC is unclear to me too… so if someone could shed some light? I would hate having to sample with a computer first …
cheers

no MPC cats out there that ran into similar? I don’t think the ADDA is causing this so if anyone had insights what the ‘correct’ setting for the I and O gain pods at the back unit is, I’d love to hear from you