Personally, I run all my signal chain flat (incl. speaker crossovers). No equalizer, tone & loudness is off in every step of the chain.

Given the same set of speakers, I'm pretty sure that almost anything I throw in to the chain will sound pretty similar (unless it's designed to color the sound some way). This is one of the reasons why I don't plan to change any parts of it .

For me the DAC has some serious benefits in the sound quality department, though. First, it doesn't have the 3dB loss like the Logitech, second I can stream AAC or aptX to it, which really sounds better than SBC, given the song is mastered correctly and has the detail which can be carried by the codec itself.

I listen to some of the albums I have as CDs in streaming services and even though it's labeled as "lossless" I can hear that the files are butchered pretty badly.