no need!
if you want to play by the book just set the H90 to instrument output instead of line if you are inputing on the front.
if you’re inputing the H90 on the back (on the fx loop) set the h90 main out to line.
I have been giving my JC-40 line impedance with no problem anyway…
if I’m not wrong it will be harmless as its solid state…
anyone please correct me if I do am wrong!
