Sorry for the dumb question, I want to make sure I have it right before I buy such an expensive instrument...

I have a hexaphonic guitar (one instrument TS output per string). The Quantum 2626 has inputs 1-2 are Mic/Instrument inputs, and inputs 3-8 are Mic/Line inputs. Is it possible to use inputs 3-8 for instrument inputs as well, or must they be preamped to line level first? The manual states that both go to the instrument preamplifier section, and only list the difference between them as 1-2 having TS connectors and 3-8 as having TRS connectors.