I just purchased a low down studion 110 amp yesterday evening.  When i began to practice with it today I noticed there is a very noticeable buzz coming from the rear of the amp cabinet.  I tried to ignore it but it is very noticeable.  I have parked all the settings to 0 % and only used master volume however the buzzing still continued.  I love the size of this amp and the sound that it puts out, however, I cant get past the continuous buzzing from the rear of the cabinet.   At one point I tilted the amp slightly forward and guess what happened?  The buzz disappeared, however, when I returned the amp back to its' upright position the buzzing returned.  Can someone help.???  Should I contact the retailer where I purchased for an exchange?

Any help would be greatly appreciated.