I had bought a Sansamp RPM about a month ago. Went to practice and plugged in front of a Harkie 4000 w/GK 410 RBH. Set the harkie flat. Played with eq, man I was knock flat. It just killed. I felt like I had a new rig. Tone, growl, volume. I can't wait to put in front of my big rig, a GK 1001 RB II w/ Auggy GS 412.