I think you will probably lose any performance you gain by playing with component positioning on shelves ,if you have to go to longer interconnects. From my experience, shorter ICs always have equated to better sound. Even inferior shorter ICs sounded better than longer run(2m or greater)better quality cables. Good idea about running the tuner as far away from the rest as possible. Not sure you need to goto the extreme of a different room. Unshielded interconnects will be an issue, however.
Placement of components in audio rack
I currently have from bottom to top, on individual shelves in an open rack stand: amp, pre-amp, CD recorder, CD player, turntable on top. This is probably a pretty normal set up, but wondering if anyone has messed around with the order and found any significant improvement? Also, I plan on adding a tuner to the mix. My past experience has been to put the tuner away from all other components for best signal; like in another part of the room with long interconnects. Thoughts?