Most of the time the DSP inside runs at a fixed rate.
In the past often 44.1, today often 96 kHz.
This means the audio will be resampled if <> 96
Likewise there will be a DAC per channel inside with its filters, etc.
DSP like EQ, volume, etc. will of course remain unaltered as this affects the bits send to the active speaker.
BTW: this is pretty much like a stand-alone DAC
Unless NOS, DAC run at a different sample rate (upsampling/oversampling) compared with the audio, have filters, etc.