what is an expression pedal?do these effects processors really sound ok, or good,very good?what if i only have a strat but want to sound like acdc?or i only have SG copy and want to sound like eddie van halen?how does it do that?or do you have to fiddle around and come up with your own setting?can you or is there any reason to run a pedal into this effects box or between effects and amp?


thanks
gdptay