PGC before the Roto. I did try it after as well with not good results.
On the Roto, turned the output down(10oclock) and drive up a little(2 oclock). I set the PGC for a lot of vol and the comp kinda let me control the amount of noise going thru.
Basically the PGC is driving the Roto better than its own drive . It does not have enough drive on its own to push the sound with the output set so low.
So with the Rotos output down the noise it gone, but it needed the PGC to be heard.
Only problem is, I like my PGC set different for most of the time. Maybe a good boost would do the same as the PGC is doing for the Roto? Or,,,, maybe there should be a PGbiC in the works!?!