A good wireless guitar system is designed to be as transparent as possible, input to output. However, any amp's input can be overdriven with too strong of a signal...but, we've been doing that with Tube Screamers and the like for decades . So, no I don't see how even a malfunctioning wireless guitar system could harm an amp unless the amp was set loud enough to possibly blow a speaker. However, the thing I miss with a wireless system is how my guitar interacts with my amp's first preamp tube...my guitar/rig just feels different with a wireless.