when vm installed just broadband router under stairs in house they didn't bother with any white isolator boxes on wall inside just cable straight from outside to router with a in-line galvanic isolator connected to router cable. I have now added a Technetix splitter (sourced from VM) on cable to supply router and boxes etc. Do I need galvanic isolator connected anymore?? As don't the Technetix splitters have isolator built in??