Hi,
I just read this in the C25 manual:
Outputs 1, 14, 16 and 17 (Port 1 and 2) and outputs 2-9 (port 1).
All those pins are directly wired to the C25 output terminals.
It would appear the output of the ESS is direct connected to the output screw terminal of the C25, no buffering.
I consider that less than ideal. The C10 has input AND output buffering and is preferred. I myself use MB2's from Homan Designs
in Austrailia, I live in New Zealand so its near enough to local for me. They are a bit more expensive than the C10 but I've been very
happy with them. They to offer bi-directional pins 2-9 and input and output buffering AND LEDs on ALL inputs and outputs so I can tell
at a glance whats happening. Those LEDs would be a real boon to you at the moment.
Craig