Hey all, I am looking to add a speaker jack to a fraken-amp that I assembled, but not in the traditional configuration.  I am looking to use the combo-amp as an external speaker cabinet, as opposed to having the amp switching to an external speaker cabinet.  I am looking at a Switchcraft 13A (transfer circuit) jack to achieve this.  Is this the right part for the job?  Will sharing the ground from the external amp, the internal amp, and the speakers work?  Do I need something to completely switch circuits (hot and ground)?  I have seen other setups that use two standard jacks, and then use a jumper cable to mitigate, but I prefer to have one input jack to keep things clean and simple.

Thanks