I have a Pro Reverb combo whose chassis code dates it to 1981. I use it primarily as a head to power an external 4x12. I use a Wampler Tumnus Deluxe for my drive, and a TC Electronic Nova System for all other effects. In the future, I want to clone, then modify this circuit into a head and have an effects loop, removal of the pull out overdrive, eventually maybe switchable impedances. My first question is: Is there a way I can improvise an effects loop, so I can have my Nova running after the preamp, but before the power amp, without frying my Nova?