Thanks for the tips. I replaced some of the connecting cables between the gcx and the amp and replaced the cable from the mcintosh to the fender tap and the hiss is much better - hardly There!
Ill hold off on the sentry, but i guess i could try it sometime on one of the channels and leave the other alone and a/b it real easy.
Adding the tap to the fender > mcintosh doesnt mean you need more volumn btw, its more for tone and overhead. Dont get me wrong, I can crank my rig and blow the hair off your head with it, but I don't! (often)
ill never go back to a stock amp after playing this sweet rig. One other thing I've noticed is that nothing else quite sounds like my rig - I think there is some magic in the twin I have, I did all of waldos suggested mods to it.
Ive tried a few other rigs and heard countless others and tehre is def some character in mine that doesnt exist elswhere. Makes me believe that even with all of the same gear, small subtle things can really change the feel and tone.