Heres what ward tried. This was to fix a peculiar sonic problem possibly related to a non Trinity OT.
He said:
"
I tried several different values and these are the most transparent, the amp still sounds like itself. The CF just removed the garbage on top. It was a last ditch effort for me besides changing the transformer, which I'm sure is the culprit. $3.00 worth of parts compared to the cost of a better transformer made sense to me and I like what it does. "
We would not normally recommend a CF in an 18 watt, this is for reference only.