Hey everybody! I recently noticed that my chieftain was producing some grainy, harsh distortion sounds when I would play at a lower master volume and a higher gain/volume on my amp. It is almost like a buzzing, boss esque gain (not the smooth overdrive it usually produces). When I would play with a cleaner setting it wasn't noticeable unless I would pick at certain frets or strings like certain frequencies and a more agressive attack made it buzz. I have tried it with multiple guitars and it produces the same result albeit a little more pronounced with the humuckers in my LP vs my strat. I have read that most of the time when something is wrong with a tube amp the most likely culprit is the tubes. Does this sound like a tube issue to any of you TGP experts out there? If so, do you think it is a preamp or power amp tube issue? I love playing and searching for great tones, but I am not the best at gear diagnostics, lol. If it is a tube issue I was going to go ahead and replace the two power tubes and 5 preamp tubes. I am pretty set on the JJ El34s for the power section, but I don't know what to do with the pre's. A lot of people say that it is beneficial to mix and match the preamp tubes. I like having the grit of the matchless and the fact that it breaks up earlier than most. However, I do love the clean tone as well so I don't think I would want anything that will inhibit me from reaching some semi clean sound. Do you all have suggestions for placement of tubes in the preamp section (i.e. v1,v2,v3, etc.) for this type of amp? Thanks in advance for any suggestions or input as I am fairly puzzled on what to do.