Installing speaker jacks on hard wired combos – despite being very simple, the act of being able to plug in an external cabinet into a combo amp and give you a whole host of different sound options.  It’s a simple mod where we install a 6.35mm speaker jack socket in the chassis, and replace the fixed wire to the speaker with a slightly longer cable and a plug on the end.  Normally it’s kept plugged in and works fine, but easy to unplug and add an external cabinet.