Connect the MPs to I/P 2 on the AFX. Put an FX Return block in followed by shunts to the end running parallel to the main signal chain. If you need more control of volume/pan, merge the two signal chains into a mixer block in the last space. That should route your MP3 signal via the AXF outs along with you guitar sound. if its not loud enough, put the "tube Pre" amp block in the line.
Connect the MPs to I/P 2 on the AFX. Put an FX Return block in followed by shunts to the end running parallel to the main signal chain. If you need more control of volume/pan, merge the two signal chains into a mixer block in the last space. That should route your MP3 signal via the AXF outs along with you guitar sound. if its not loud enough, put the "tube Pre" amp block in the line.
Feedback return isn't the block to use; that's for routing within the Axe layout in combination with the feedback send.
Place the Effects Loop (FXL) block in any unused space in the last column. No connections to FXL from the previous column are needed. Signal at In 2 will be output from the FXL block and go to Output 1.