Hi Sam,
The signal chain may well be different for different source tapes--whatever it needs and no more, that's my philosophy.
In those cases where frequency response shaping is needed, I have used the E.A.R. 822 and 823 EQ's, and maybe the E.A.R. 825.
Whatever I choose to use in a given case, it is all direct connected, no patch bays. I don't run the signal through a console (though I have one,) not even a master fader, and anything not in use on a given song is not merely put in bypass mode, it is not even in the chain.
The Stubb-U-Sonic process is less about specific gear, and more about attitude and approach.