@eazanotti, I don’t see a reason to put on a pre-master (depending on the terminology your DAW uses). Just put it right on the master. The way I could see the NLS on a pre-master is if I was combining it with a REAL summing mixer, but that would be kind of crazy imo. So yeah, just stick it on the master 2 bus. It doesn’t matter which plugin slot its in. Works the same way either way. I typically put it first. Then might follow with a Massive Passive or a Pultec. Then hit the SSL or Red3 bus compressor then out.
When using a real summing mixer it’ll go as follows
Stem 1 - summing mixer
Stem 2 - summing mixer
Stem 3 - summing mixer etc…
Summing mixer -> Massive Passive
Massive Passive -> SSL Bus Comp
SSL Bus Comp -> Return to DAW (Print Track)
You can see where it differs a little from the way you’d hook a real summing mixer up. The signal flow isn’t the same. You could probably get a little closer by switching your DAW track insert slots to post-fader/post-pan if your DAW has the option.
Actually at this point, it would be helpful if you told me which DAWs you use.
…and one more thing, take a look at some videos on the way real summing mixers work. That might help make things make more sense.