Hello!
Thanks for your post.
Let's see how I can help here.
Q: do i need a different device to plug in multiple instruments !? ( key, mic, guit, bass ) and create a live track with loop effect ?
A: The
iRig Pro Duo would be the suggested audio interface for multiple inputs at a time. To create a live loop, AmpliTube 4 for Mac/PC or AmpliTube iOS would be great options. These are included with the iRig Stomp I/O product's registration.
Q: How much processing on my laptop would i need to do all at once ?
A:This would depend on the software you want to use. For AmpliTube, you can find the minimum requirements
here.
Q: What would be the best output ? monitors or amp ?
A: I would suggest monitors like the
iLoud Micro Monitors for studio use, but most output sources would really work in theory. The reason I suggest the iLoud Micro Monitors, is because they can be used to not only playback your guitar signal, but they work great for mixing your projects.
Q:Would it be better with a sound card for live or recording?
A: The iRig Stomp I/O is really the best of both worlds. With the option for 96kHz/24-bit recording, you get a studio quality interface. With the robust build quality and MIDI controller options you get a live controller that can pretty much do it all.