Issue with effects loop

[J.custom]

Hey guys, every time I plug in my delay and mods into the efx loop of my amp head and switch the OD channel, there seems to be some flickering noise when i just chug the low E string. I've checked cables, PSU and everything else, seems to be ok. Could it be a problem with the efx loop?

 

[dodgethis]

Connect the send and return directly to each with a patch cable and NOTHING in between. If the problem persists, your effects loop is screwed up.

 

[J.custom]

tried that and it sounded ok. swapped between 4 different cables to make sure that it wasn't the problem with cables. Just to double check, it's send>efx>receive right?

 

[Godspeed64]

Does your delay have a killdry feature?
I'm not so sure since I prefer hitting the front-end of my amp.

 

[J.custom]

Nope it doesn't. It's the Muza FD900. I'm using my amp's OD channel, that's why I have to put them in the loop, if not I would have just dumped them in front. haha

 

[J.custom]

I tried the individual pedals in the loop, and the noise was caused by the delay pedal. Tried it in the front of the amp, it works OK, but not how I like it, too 'in your face' because the distorted signal is going through it. hmmmm