QX24 is one half equalizer, other half exciter. It
is authentic design and there are just few other
plugins that offer comparable functions without
getting too complicated. Using it properly you'll be
able to accent parts of spectrum where instrument's
character resides making it more prominent, while
gently reducing remaining frequencies that often
clutter the mix. Sound gets harmonically enhanced
mostly with first two harmonics, but if you push it
past moderate drive levels it gets much brighter -
experiment and find the best way to utilize it.
QX24 is available to download as a
freeware VST effect plug-in for Windows.