Long term Jazz bass player here but I have a question. Over the years I've often heard folks complain about the hum Jazz basses can have when not set at the same volumes. I love the Tone of Jazz basses and frankly have never really had a problem with the hum except in VERY minor ways and even then it was not a big deal at all. I primarily use GK amps these days but it never became an issue with others I'd owned. ( Ampeg, Fender) I just played somewhere a few days ago ( used the same amp previously with no issues) and they use an SWR 100watt combo for a monitor. I had loud buzzing with the pickups equaled and way more when I tried to vary. I just gave up and played and it dissapeared during the gig due to all the other players. I also noticed I was having a hard time hearing myself turned up quite high on the amp. No Flourescent lights nearby. I Really like the tone of my MIA Fender Jazz even more so since the addition of a series/Parralell switch and I'm not going to consider a hum canceling set over one instance ( Dimarzio model Js on my MIM Fender Jazz already) Any ideas about why it happened? Thanks.