I'm playing the FX100 through a vintage Gibson amp, but what I'm doing is turning all of the AMP MODELING stuff off, and just running FX and stomps through my amp. It sounds amazing. It doesn't make sense to have the AMP MODELING on when running it through another guitar amp. If you're plugging directly in to a PA speaker, or something w/o it's own coloration (like a guitar amp), then leave the AMP MODELING on (e.g., PA speakers, the Line 6 Bluetooth speakers, etc.). Does that make more sense?