It might be a bit more complicated with Express. I'm not sure if Express has the I/O plug-in; with that plug-in you can plug an external effect right into the track you want to process. So if Express has the I/O plug-in, that's how easy it is.So...can i do this with Logic Express??
Must work, your setup is ok. You need a cable from the Saffire output 3 to your pedal, from the pedal to Saffire input 1, exactly as you described.In my mind, I'd I/O to the channel strip, route the signal out channel 3 of the Saffire to the effects pedal, out of the pedal back into channel 1 of the saffire, thus completing the loop. That didn't work on the channel strip.