how do you hook up a pedal to your amp?
What kind of pedal?
a multi effect pedal like a digitech RP250
Plug a cable from the guitar into the IN on the RP, then from the out on the rp plug it into the amp. Id suggest using the clean channel on the amp for that pedal.
so thats the aux input?
There should be a MONO input on your RP unit, plug your guitar into that. Use the mono out or left output and plug that into your amps input.
Sure let me know how it works out for ya