Alright. So I have a 4104 combo amp and a twin reverb that I have going in a stereo rig. Everything seemed fine, but I rearranged my pedal board because I got a CS12 power supply and got rid of most of the daisy chains. I’m running 17 pedals counting the tuner, but I never noticed this issue when I was running the daisy chain (just the horrible hum is all hints the one spot iso supply) and I have never heard of this problem before- when I have my Marshall plugged into any other available plug in my garage my TWIN starts to crackle. Now I know my Marshall needs to be serviced (tubes crackle a little when it’s warming up) and I JUST had the tubes replaced in the twin and it happens when everything is unplugged so it isn’t my pedal chain and everything is plugged into power conditioners or surge protectors coming out of a power conditioner. Even when the Marshall is off but the plug is plugged in it still crackles (in the twin) however if the plug is in the power conditioner/surge protector but unplugged from the Marshall it stops. So it’s the Marshall. Why would my Marshall make my twin crackle???