Mixer question

[Mitchell Hudson]

    I got a mixer a, it's a mackie, a little while and back and am still
figuring it out. I just realized there is a little switch that shows the
input level versus the output. After playing with this for a little bit
I find that even with the trim turned all the way down my input levels
are in the red. I am routing the the audio out of any patch that I setup
directly to the mixer. Is this bad? Should I be attenuating the signal
before I get the mixer? Can this damage my mixer? Or am I just paranoid?

    My synth is a collection of TomG, Blacet, Paia and few home brew
modules. I guess the output should be in the range of -10 to 10v.

--M