are these tests being done with the loop active on the 3 channel DR? with the loop active it makes a huge difference how you gain stage the master level into the output level, it has a huge effect on the final tone. low master into high output, or high master into low output. also if the loop is active it makes a big difference what the FX send knob is set at on the back. if you bypass the loop, the master pots have such a quick taper that you can only barely crack it before the power amp would start to fold, it's a lot better tone to use the loop active and find the sweet spot on the output, then feed it master level until the bottom fills in. my Dual rectifier model tone search is over, i just got brainworx mega dual and mega single today, beats amplitube mesa by a long shot, brainworx modeled the loop circuit so you can dial in the sweet spot right between output and masters, and has a built in power soak. between that and the new two notes mesa pack i am a happy camper now.