I always felt that, if it has a power amp on one end, use a speaker cable.
Well, this doesn't.
Bonus: Reading the manual it suggested using the 4ohm out on 50 watts, into 8/16 for crisper/tighter tones....have to try this!
It's certainly wired up right the way you usually run it from the speaker out. Is this with an all-tube amp or a solid-state or valvestate? If it's a tube amp (tube power amp), you got lucky not having it hooked up to a cabinet. Solid state amps don't care.
I think you misread.
This is an all tube amp
I just ran head to cab with a speaker cable, and also ran slave to board through the Redbox direct. I guess I could just run quarter to XLR out of the Slave if I wanted