a hiss is likely tube noise. different tubes will effect that. some better some worse. some great sounding tubes will have some hiss. part of owning a great tube amp. I had a vk60, now have a vk75se. I have this buzz as well. must be some sort of group loop. do a search on ground loops and go through that process.
Can you hear the buzz more than 1-2 feet away from the speakers? That's about all I can hear...
Can you hear the buzz more than 1-2 feet away from the speakers? That's about all I can hear...