So I put a new verb tank (9AB2A1B) in my DRG C+ long head a few months ago and its so sensitive. When I turn up verb , with the cooling fan running, the fan makes a hum come through my speakers. Not a constant hum but gets louder as verb pot is turned up. Un plug fan, hum is gone. I put the rubber grommets in with new tank. I tried putting rubber washers under fan screws. Still there. Any one have any other suggestions? And, what made my new tank much more sensitive? If I remove that 120pf cap on V2A will that reduce verb some? I'm gonna put old tank back in and A/B them to see if it's new tank. Any help will be appreciated. Thanks, Jim. Side note: the original fan cord broke on male side so I soldered and heat shrinked a piece of extension cord (male end to plug in chassis). It's a little longer than original. Wondering if that may be an issue being so close to PT.