I have the Spider IV 150 watt head half stack. A1; A2 being channel A 1 and channels A2. The first and second factory presets. I believe the song preset tone was Johnny B. Goode. The manual says that you can't overwrite the factory presets. You can only tweak those (or create from scratch and store) in channels A,B,C or D, which is what I did. I stored my edited version of that preset in the channel A first and second presets. In other words, I tweaked those versions saving them in A1 and A2. When I get out and go back to the presets using the presets knob and navigation dial, they seemed to be saved in there. I was wondering how to clear what I saved and go back to the original settings in the using the presets knob. Thanks.