I have read, when using the direct out there is no need to have a cabinet connected to the head.
My question is: is this in general or only when the direct out is engaged?
I would like to slave another amp from the effects send, without using a cabinet connect to the origin 50 head.
I wonder if the dummy loads is always on
Yes, the Origin 50 can be used without a cab connected.
You can use the DI output to run into a separate slave amp.