Amp Setup Question

Ok so i got my new amp today, plugged it in and was a little disappointed at first because it didnt sound right.
Obviously i'll need to spend some time playing with the equalizer settings and what not..
Anyway on my amp ive got Low, Mid, Shift and High.
I tried googling, but cant find what the Shift is, anyone know?

I'm guessing from your pic in the gear thread that its a Peavey amp your talking about.

Don't know if this is the same model as yours but it explains the shift control.

http://www.peavey.com/media/pdf/steelguitar/nashvilleseries_tonecircuit.pdf

nah its a different model, but it should still apply to mine
my amp has 200hz to 2khz though.. meh
thanks