Ebtech Hum-X

Very easy. It's just a power adapter plug.

I have read other reviews from people who love this thing but I found it to be totally ineffective for my needs.
Aside from my amp, I have a rack system with a Furman Conditioner, a TC Electronic effects system and a Fender rack tuner. Also in the rack case I have a ISP Decimator for my amp's front end and a BBE Sonic Stomp Pedal at the end of my effects loop. Those two pedals where powered by a Visual Sounds One Spot adaptor connected to a daisy chain. I figured out that it was this adaptor that was giving me pretty substantial buzz. If I take off the adaptor and put batteries in the two pedals I have no noise at all.
I tried plugging the adaptor into the Hum X and nothing changed at all.
Just to be safe I tried it with all the other components in my rig and I still got no results. The only way I can get rid of the noise is if I take out the pedals completely or use batteries in them.

Overall, I don't think this device is properly advertised because it obviously doesn't work they way you'd expect it to. My rig is slightly complex but there is only one element causing noise and this is supposed to take care of that one element but for me it did not. Also I could understand its realatively high price tag if it really worked miracles but it's a lot of money to spend on something that may or may not work.

Just plug the power cord of the equipment affected with ground loop noise into this adapter and then plug the adapter into the power outlet. No other information is necessary for its use. Red LED to indicate that the outlet has power.

It will not affect the sound or tone of the gear it is used on except to alleviate 60 cycle ground loop hum. If you can get rid of your hum by lifting the ground on the power cord then this should work for you. If the hum remains then this device will not help in your situation.

It is completely molded in hard rubber so, I doubt that it can brake. There is the possibility that the devices that are used in this Hum-X could fail and potentially leave you in a hazardous situation. After briefly analyzing the input to output ground connections I found this to be very similar to a galvanic isolator that is widely used in the boating communities for ship to shore power connections. It appears that there are two diodes and a 1Kohm impedance that are connected in parallel from input ground to output ground. The parallel diodes are configured back to back so that there is a 0.7volt drop in each direction. Since I could not look inside the unit the diodes are an assumption on my part? they may have used transistors configured as diodes. The potential safety hazard here, is that one or both of these diodes could fail open leaving the user with no safety ground.
Ebtech should incorporate a way of verifying the circuit between the input to output grounds is functioning properly for safety concerns.

I called Ebtech to inquire about UL approval and they connected me with the Director of Engineering. He explained to me that they do the same testing on these as UL would perform.

Basically this is a safe cheater plug adapter. With the lack of any safety agency approval I would be hesitant in using this where myself or my company would be liable for injury. If you are at home and use ground lift cheater plugs then this would be a safer alternative.