Hello JacoPastoriusJamerson
To try and reduce any latency you can do a few things. Firstly, you must make sure that up-to-date drivers for your interface have been installed.
Then, once AmpliTube is open, go to Audio MIDI Setup in the Settings menu and do the following:
1) In the Input and Output device check you have your AudioBox USB selected.
2) You can then reduce your buffer size to reduce the amount of latency you are hearing. How low you can get it without hearing breakup of signal will depend on how quickly your processor can work.
JacoPastoriusJamerson wrote:Plus the sound is not clean I hear king of a whisper even if I'm not playing. Is this linked with the quality of my bass, of my computer?
This could be a number of things, such as the quality of your jack cable, interference being transmitted via your bass's pickups etc, but also it could depend on the signal chain in AmpliTube. If the stomp/amp/cab combination you have chosen has a high gain element this will introduce some noise, just as real amps and cabs do.
Hope that helps.