Hi Euripides,
when your amp fx loop is in parallel mode you will want to set any of the Eventide pedals to Kill Dry mode.
The reason that you are hearing phasiness in the sound is from the AD/DA converter induced latency of the digital dry signal path that the Eventide pedals utilize.
In my experience an analog dry thru scheme causes less issues with most time based fx algos but Eventide had their own vision n this area.
The Kill Dry parameter is covered in TF manual.
Good Luck!
AL
