Hi Jan
several details are important here:
-how did you connect the Eclipse to the FX Loop? Type of sockets and cables.
-is the fx loop a +4 dB line level or -10/-20dB instrument level type?
-is the fx loop parallel or serial?
-which preset is giving you the problem? You must specify name and number.
-is there anything else connected to this amp, other than your guitar and Eclipse?
thank you
I