Sorry i should have explained my slef better, i meant if you wanted to use a pre amp back into the box. Should you bring it back down to Mic level from Line level as the final stage before pre amplification ?
IE Box > > IO > outboard fx > summing mixer with -40 db pad > into mic pre on io > back into box
i read this post ,
https://gearspace.com/board/11742873-post50.html
Seems like good info