Ok, in my case, my "Summed in" example is referred to a preset like the # 6523 TC2290,
this is my general setup:
2) rack guitar stereo preamp
3) Mackie 1604 VLZ3
4) Eventide H8000FW
This is the way in which I route the signal:
from one Output of my guitar Preamp I go in one mixer's channel,from the second Output of my preamp I go straight into the Analog Input 1 of the H8000.
My Mackie mixer has 6 Aux Sends knobs, I utilize one of these Aux sends to feed the Analog Input 2 of the H8000, So, my Eventide two analog inputs ( 1 and 2) will be feed from a stereo source, the first coming from my preamp Out and the second one coming from the Aux send of my Mixer.
In this scenario, by utilizing an "Analog A->B" or "Analog A||B" routing, I've noticed when if I feed my TC2290 preset with mono, that is only utilizing one guitar preamp or just one Aux send, ( here only One green Led will light up on the left screen of my H8000)
it sounds slightly different compared when it is feed from stereo (Preamp Out + Aux Send simultaneously ) ,I don't know why.
So, my question is: which is the best way to feed a Summed In preset ? should I feed it with Mono or with Stereo source?
Let me know,