Lack of headroom with new pc for recording - please help!

[mixsit]

You're correct. The problem is occuring when I play audio back from my daw through the zoom. So I'm assuming the audio is digital. And again, the same zoom unit did not have this issue on my previous set up.
I am starting to make adjustments by keeping the levels lower, but it's still something that I wish I could diagnose.

Have you searched or looked to Zoom- support, forums maybe IDK?

 

[mixsit]

So do people tend to use preamps as interfaces, or are they using them usually prior to an interface? I guess this begs the larger question of what are guys typically using as interfaces in home studio set-ups, assuming they have around $300-$500 to spend? Are they using preamps, mixers, actual interfaces like the focusrites, multi channel recorders like the zoom? Or is it all over the map?

Preamps are not interfaces, they're just mic amps. Interfaces can, often do have pres, like the Zoom there.