Vox Pathfinder 15R Guitar Amp Features Input Jack. Standard 1 4 jack for guitar connection. Gain Control. Set higher for crunch and distortion sounds and lower for cleaner tones. Boost Switch. Press in for more gain and distortion. Press out for cleaner sounds. You can turn this function on and off remotely with the optional VFS2 Footswitch. Volume Control. Controls the overall volume. Set high for clean sounds. Lower the level when setting the Gain control high for distortion. Treble Control. Adjusts the higher frequencies or treble in your tone