I am at max gain, 34KHz HPF, Single-Ended input configuration and 10K input termination on mine. I also have variable threshold via a potentiometer. (documented earlier here in WxForum somewhere...
)
I have tried to make my "green" as "red-like" as possible.
p.s. I think maximum gain is actually 170. (per documentation and my gain calculation spreadsheet)
Greg H.