Is amplifi 150 better than 75 for bass guitar? I noticed that there are some bass effects in amplifi app. Can both amps really reach the low bass frequencies since it's full range system? Will the amp speakers be damaged? Interested to get it since I'm using it for acoustic guitar, electric guitar and bass as well. What is the USB port used for? Can USB be used to record with any daw? Is the input Jack stereo or mono? Thanks