The Mark V and FX8 work excellently together. I've used that as my live setup without fail for the last year before switching to the JP2C. I have experience with the relays for channel switching, which showed no audible lag even with my 20ft trs to ts cables. I will suggest purchasing humbuster cables from either Fractal or a reputable cable making company if using the 4CM (4 cable method). The ground loop hum is so loud it makes the amp unusable even with a gate.
