I've got a couple of Rev. E's and I couldn't get a lead boost out of the thing using the parallel effects loop. Do I need to have the effects loop modded to series to be able to do this?
This. I've never had a problem with leads cutting through. Honestly, I never use a lead boost live and never have a problem with people hearing the leads on my Rectos. Of course, I'm a minimalist when it comes to effects.