Hi folks, i'm having a hard time with a vintage BF bandmaster ! I changed all the electrolytics : filter caps, bias cap, cathode caps. tubes are new and biased. i tryed different preamp tubes. pots have been cleaned with deoxit. All coupling capacitors have been checked for leakage and value - they are ok, and only a few mV passing trough on the circuit. The amps works great, trem is good. All resistors are stock. BUT my 2 vol pots are scratchy and i without touching the pots i get an intermitent "scratch scractch" that does not seem to be related to volume. it come and goes. i tried to swap some resistors (plate load of V1, V2 and PI) with no luck. I even tried new coupling caps at some places, no luck. I don't want to check every component, i'd like to keep the original soldering... Any thought? it's driving me crazy !