buckler57

So there is an FX loop off/on switch on the front of the amp in broad daylight I apparently overlooked... It was not enabled thus why only the front of the pre-amp had any effect. Embarrassing... apologies but thank you for the fast response and input!

All cables are set up like you have listed. FX Block is on and amp does have serial fx loop with a mix knob. I have mix knob set to +6dB thinking this would help but adjusting the mix knob seems to have no effect.

I have a Marshall JVM410HJS (serial fx loop) that I am trying to integrate my hd500x with via 4cm. I seem to have everything connected properly. All effects before the preamp (in front of the fx loop block) work fine but when trying to putting any after the fx loop block (ie reverbs, delay, etc.) I am getting no sound from those effects. Moving them in front of the fx loop block is allowing them to work but I want them after the pre-amp of my Marshall not before. Any idea what I'm not understanding or missing would be greatly appreciated. Thanks!