I am not sure what to call what I am looking for but I will do my best to describe it....I run a rack with multiple preamps in it. I am looing for a single rack space device that I can plug into and it will send the signall from which ever preamp I want to use.....instead of unpluging and rewiring the rack every time I want to switch preamps.... Do they make such a thing? What is it called? Where can I find it? Thanks!