Yes, backing is possible:
1. Cable mini jack stereo - 2 mono TS hooked into input 3 or 4
2. Input 3 or 4 block „wired” in the patch to out1 together with pach „wiring”. Then you will have backing and patch in guitar.
The disadvantage is that you have to do it on all patches you use. I have IEM input done that way, out1 and 2 are amp, FOH and monitor mixer, out 3 is patch and IEM mix to IEM transmitter.
With computer plugged with USB is easier, you can choose PC output AxeFX3 driver and you can have all audio from computer on Axe out1 or headphones together with patch „wired” to out1.
Axe does not have aux in as a proffesional device. If it is good or bad I do not know.
Axe3 is nice and decent to control without computer, but personally I have 11” laptop for music purposes (AxeEdit for 2 and 3, multitrack, backing mp3’s and so on), for me it is more comfortable with bigger screen. Hooking up USB cable or mp3 player cable - takes the same time. Maybe PC starting time is slightly longer than mp3 player, but PC is more versatile. You have to think it yourself.
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