Changes

True pre-amp pedals should be considered identical to rackmount pre-amps or the pre-amp portion of a full amp. It's not a wise idea to daisy chain pre-amps, which you'd be doing if you ran a true pre-amp pedal into the front of your amp. Other distortion pedals, regardless of their price or brand, should be considered the same as classic distortion pedals, designed to be run into the front of an amp. Some distortion pedals can be run directly into a power amp and sound good, but the problem there is that you usually don't get a clean tone, other than the direct guitar signal, which tends to sound percussive, nasal, and bright.