Line out means it should connect 2 a LINE i/p, not a mic i/p.

Pro line level - +4dbm @ 600 Ohm.

So U should (if U want 2) connect gtr>amp>line i/p.

U'll b getting the 1st gain stages of the amp, usually eq included - a "colored" tone.

It has nothing 2 do w/ quality, just taste.

The amp is not "cutting" ur gtr, it amplifies it.

As levels go:

Gtr o/p level may vary from -anything dB to line level when active.

DI out = mic level, depending on source. Mics r often amplified by ~ 40dB, again, depending on source and model.

Line out, preamp out = Pro line level - +4dbm @ 600 Ohm

"Home", consumer line level - -10dbV.

Peace,

Zooot