The 44 has a series effects loop, the loop circuitry is always active, even when nothing is in the loop.
The effects loop is an integral part of the 44’s design and sound, it’s not an “add on” loop circuit, it actually enhances the 44’s sound, even when nothing is in the loop.
The “default” effects loop settings are with the Send and Return wide open, think of these controls as mid-preamp attenuators — leave them wide open and trim them back when needed.
On the other hand, you can also get different preamp drive tones by experimenting with the loop Send and Return levels, since these are essentially mid-preamp gain controls.
The 44 has an all-tube buffered effects loop, it works great with most pedals unless the pedal, etc. has a very low input impedance, this could be the case with your Eventide.
Try running your Eventide in the 44’s input, or you can try adding a buffer pedal between the 44’s effects Send and the Eventide’s input, that should help if the problem is impedance-related.
