Small fixes like thicker grips or heavier bar end weights will provide some relief for the vibration issue on your KTM 390 Adventure X. You can also look at handlebar dampeners, although that will be a little on the expensive side.
Another option you can look at is changing your sprockets to change your gearing so that the zone you find yourself in the most is as buzz-free as possible. Do bear in mind that putting an aftermarket sprocket could void your warranty, and we'd best advise you not to do so on a brand-new machine.

