I understand, Rich.
This is a common problem with loud amps. The fx loop requires a certain level to drive fx unit properly…and this *may get loud*. Most amp use Volume to control fx loop send…that's ok.
I wouldn't use what you have been testing, 1/4" jacks, as the minute you need/like to crank your amp up a bit, Eclipse will be overdriven to nasty digital clip. Stay with XLRs to 1/4" and set Eclipse IN GAIN all the way up, to +10dB, while reducing its output level a bit. If that is not enough you may need some kind of balanced boosting device between the fx send and Eclipse input (not a very common solution) or simply play your carvin louder.
best
I
