Hello, Tomorrow, my Warm Audio WA12 pre-amp arrives. Primarily I want to use it to record vocals, but I also would like to send some pre-recorded tracks through it to try and add some warmth. Having done a bit of reading, I'm confused as to how to set this up, as it seems that there are a number of options. Firstly, am I getting the physically routing with cable correct, I have a Saffire Pro 40 interface: 1) TRS from saffire output to TRS into WA12 Mic input (on the back) - or does this go in the front input? or do I use XLR? 2) TRS (or XLR?) from WA12 to TRS Input on Saffire. Is this correct...I never know whether to use TRS or XLR...what's the rule? From then on...I'm stuck...How do I send audio through the pre-amp. Do I set it up as a plug-in? If so how do I actually do this? Thanks a lot Neil.