Hello, so I decided to buy Rivera Chubster and I'm absolutely delighted with the sound it produces, very high quality clean channel. There is only one but. The amp is making some noise (it's like 'hissing' in the front, and kind of "hambucker humming" noise in the back). I am enclosing the video for you to listen to. I am just curious whether this is a significant problem, or just a minor/tube related issue, easy to get rid of. Also similar 'hissing' sound is being heard in the video below from 06s-24s, when they introduce themselves.