I’ve found myself unable to use the MOD DUO recently due to a very ugly whine it makes. I’ve tried plugging it into the same circuit as the amp and I’ve run a cable to another circuit. I’ve tried a variety of pedalboard configurations as well as with nothing. I am running it alone when I try and I’ve worked through a series of cables, guitars, and amps all the the same effect. I’ve tried running with no pedal emulations and without. I know many of us report similar issues and I am curious if it’s the power cable that comes with the DUO.
Below is a sample. Note this is on a clean channel of a multivalve Dual Rectifier.