i was given a 2007 model sv mk 1 and while the clean sounds are very good ,turning up the drive encoder on any model results in a real nasty "barkY"(i guess thats a word) .tone.. very grainy...the tone controls seem to have minimal effect even after I spin the knobs to start at "0".the tubes are orginal .and one of the power tubes has a bright blue ring around the area where the plate(?) ends . any ideas??/id like to keep it.
Posted 14 May 2013 - 07:02 PM
+1...Sounds like one of your power tubes is going...That can put the amp way out of bias. What that means is the top (+) of the sine waves will notch as they cross to the bottom (-)...The result is generally exactly as you describe...the tone gets unusually rough really quickly. Good idea to change all the tubes on this one I think...and adjust the bias proper for the tubes you get....