I Just started playing bass a few months ago. I have a 12w practice amp. I just upgraded to a Ampeg 35w demo. Im getting a lot of buzzing and vibrating from the cabinet. Is this common? The volume is only set on 3. All controls are at noon. I was planning on returning and ordering a new one in the box. Or I was concidering going with an orange bx25. Do all amps buzz some?