There is a loud popping noise when I am switching from ultra gain to classic gain channel while still holding or playing, but does not occur when going from classic to ultra. Also my loop pedal's volume is significantly lowered when on the ultra gain channel. Could this be a tube or footswitch issue? Is it easily fixable or do I need to take it in so someone can take a look at it? This was also just purchased on February 3rd 2018. Any help is much appreciated because I absolutley love this amp.