yeah, that is true. I ended up using a trs cable out of the output jack on the back of the spider 75w into a yamaha mixer to a AB International amp then out to Peavey Pa cabinets with Black Widow speakers and a horn...sounds great.
my Spider IV 75w requires a TRS line out. wanted to use over a Crate 4x12. to connect it, I need a single TRS on the amp side to split Right/Left connections on the back of the cabinet. Can't find the cable...