This is something new that has been happening with my head. At low volumes (or high) it's breaking up and distorting when first turned on. It appears after its 'warmed up' it stops happening. (Mind you, there are no tubes in this Eden head.) I'm not sure what to do, as its my only head and don't want to send if off for repair. This started happening recently, and the only change I could think of that could make this happen is the new cab I'm using. Its a 4ohm, as apposed to my old 8ohm cab. What should I do?