I have my H90 in the effects loop of my Quad Cortex. When I enable/disable the effect loop block in the QC, there is a noticeable boost in volume. I have the send/return levels set as normal on the QC and the H90 in/out gain is at 0.0 db too.
What do you mean by “running it in parallel”, precisely? It’s in it’s own effect loop block on the QC, and the signal chain is straight through that block (no splits before the block). Within the H90 though, depending on the program I have presets A and B in series or in parallel.
If you are not running it parallel to your dry signal but in series on the quad core then it must be a send return level issue. If you just have just cables in and out and you use the loop does the level stay exactly the same when you turn it on and off?