How can I invert the phase at line level

[ben62670]

I have tried searching for some info on inverting phase on line level outputs. If anyone can help it would be greatly appreciated.
Thanks Ben

 

[richie00boy]

inverting op-amp

search for schematic, it's one of the most common in the entire world

 

[ben62670]

Yeah I'm trying to do it passive if at all possible

 

[richie00boy]

reverse speaker leads or do it active