TWO BLACKStAR FLYS ...2 more inputs?
Posted: Mon Aug 19, 2019 9:20 pm
If I use another Super Fly INSTEAD of the ext. cabinet ...will all 4 inputs work?
I know this is over a year after your OP.
The XLR output from the main amp is stereo. The XLR input on it is balanced mono. Anything the same in both channels could be cancelled. It should work as you hope, if you feed the XLR out from one into the other's line in.