I use an Ernie Ball VPjr 25K and another big old Ernie Ball Volume pedal. The VPjr works flawlessly with the Factors… the old one, not so much. But, I plug them both directly into my Liquidfoot Jr. and that calibrates to whatever expression pedals you use. So, the Impedance of the old one isn't an issue for me.
If I were to plug straight to the Factors instead of going through the midi controller I wouldn't hesitate to get more VPjrs. They're pricier than other options but, as roverdog said, they seem *way* more solidly built.
