I'm assuming these 4 fx loops are not true bypass, correct? I run two overdrives for crunch and lead tones into a separate preamp, and I've been running them before the Helix with great results. The only downside is that I can't program the overdrives that way. So, I tried tossing the ODs in a loop at the start of the signal chain and the preamp in a loop for the following block. The switching works exactly how I want, but I'm getting a not-so-tolerable white hiss when playing the clean setting :( I've tried messing with noise gates, in different parts of the path even, but still no luck on getting rid of that bleed through. If somebody has a fix for this, I will give them numerous e-high fives.