Question When putting the G-Major in my amp loop the output level of my amp drops, why is this

By default the PRESET OUT LEVEL all factory presets is set to -6dB in order to allow you to use the PRESET BOOST function. When playing a solo, you could then boost the level with 6dB by enabling the preset Boost function with your MIDI footcontroller to make you able to play louder. You can assign this function to your Midi controller via the MOD menu. When you do an ALL BYPASS on the G-Major, you will here this level difference of 6dB. To go around this, you should save the patches you need in the user memories and set the PresetOutLevel (in the Levels All menu) to 0dB instead and restore the preset. Please note that in this case, using the PRESET boost parameter will not have any effect.