The punch is usually made by pushing the amp... "Pushing" meaning running it at it's highest point of output... What tube amp owners often do is get something called an attentuator that allows them to "push" the amp as much as possible but still turn back the volume.... With solid state amps like the Line 6 amp that you have it's a little bit different... you have to tweak on the knobs quite a bit... In the end what you're probably going to have to do is crank your amp and use the volume knob on your guitar to adjust it to the appropriate amount..... it will give your tone that full sound while giving you the control over the amount of volume your putting out....

A lot of people neglect the volume control on the guitar... they always have it all the way to ten..... The volume control on your guitar can work as an attentuator if you use it right... it can also work as a gain control because you'll notice that it bleeds off a lot of distortion when you turn it down... Just try that out and see how it works gfor you