My Helix is getting what sounds like 60 cycle hum with some amp models, (US Small Tweed, US Deluxe, Fullertons) but not others.
The noise occurs even with nothing plugged into the input. It can be heard thru the 1/4" outputs or thru the headphones.
I've tried different cables, ground lifts, etc. but that's not the problem.
The US Small Tweed is the worst. The hum gets louder when the Ch Vol is turned up but the drive level has no effect on the noise level.
Other models are dead quiet: US Double, Jazz Rivet 120,Cali IV, etc.
Strangely the Grammatico Jump also has a hum but it's about an octave lower than the other amps. Weird.
Has anybody else had this problem? Do you have a solution?
Thanks