Just recently did this is a common mod for that people do for the Blues Jr. On a Blues Jr. III it’s replacing R25 with a 25K pot. It’s basically an implementation of the Blues Deluxe presence control on the Blues Jr. Billm uses a shielded cable when he wires it in, so that’s what I did. Makes quite a special amp with the other Billm mods, a Warehouse Guitar Speakers ET-65 and salt and pepper vintage grill cloth.
