How would i typically do this?
My preamp is an old mesa boogie studio pre.
It has mono send and stereo return.

I tried connecting the send out to the top row (1) and the stereo returns on the bottom row ( 1 and 2 )
The connection is half normalled. When i patch the signal into an effect unit and return a stereo signal everything is fine. But if i only wanna use the preamp without any effects (just the normalized connection)
it will only be on the left input, obviously because input 2 isn't normalled to anything. I found out that removing
the jacks from the fx loop connections at the rear of the preamp gave me signal on both channels. But id like to know if there are something else i can do to be able to have a stereo output while the fx loop connections is connected to the patchbay (when no effects are connected to the fx loop in the preamp)