Hi All, Quick question regarding an issue with installing this. My father is in town and wanted some mods on his Fender Champ 600. I disconnected the pseudo tone stack, disconnected the nfb, and replaced the weird speaker cloth with something more acoustically transparent. Dramatic improvements with those alone. However, the master volume I installed (250k pot where “R4” or the 220k resistor was coming off of the 6v6) is behaving strangely. At minimum, it works as expected - no output. Turning it up slowly works as expected - the amp gets increasingly loud. At what should be max output, however, it suddenly gets quiet again and then silence. So, the output is cut off at both sides of the dial. Any thoughts?