Checking for electrical interference using a guitar amp

[Old Joad]

Say the plug isn't messed up, is there a work around to ground the amps?

Edited September 24, 2020 by Old Joad

[Old Joad]

I was thinking after I test the plug, maybe something like the ebtech hum x ground line voltage filter would help.

 

[bitflipper]

Sorry, OJ, I didn't notice your last post until now. Here are my thoughts on the Hum-X product...

It's neither a filter nor an isolator. It works by inserting a series resistance into the ground connection. That limits current, which in turn reduces the amount of electromagnetic radiation from the ground conductor and thus reduces hum.

It's a less-drastic version of what happens when you use a 3-to-2-prong "cheater" adapter. The cheater completely opens the ground conductor, so there can be no current. Unfortunately, it's a violation of code because without the safety ground you could, well, fry.

To get around this, they place a pair of diodes in parallel with the resistor. The idea is that if the current ever gets high enough (e.g. due to a ground fault) that the voltage drop across the resistor exceeds the threshold at which the diode starts conducting, the diode will then effectively bypass the resistor, allowing full current flow and assuring that the circuit breaker is tripped and you don't die.

Assuming, of course, that the fault current isn't so high as to destroy the diodes, in which case you now have an unsafe situation as there is no longer any safety ground. Even worse, you won't know that you're in danger without testing the Hum-X device with an ohmmeter to see if the diodes are still intact.

So does Hum-X work? Yes. Assuming that ground current is in fact the source of your problem. There are other ways to pick up hum that Hum-X can't address. 

Is Hum-X safe? Probably. I'm guessing they had to demonstrate high reliability in order to be allowed to sell in in North America. They don't sell it in Europe, although I don't see any reason why they couldn't design a higher-voltage version for Europe. The principle would still be the same. Maybe they couldn't meet the higher EU standards of safety, I don't know.

Is Hum-X the only/best solution for a studio? No. It's for situations where you cannot change the actual underlying problem, such as in a nightclub where you just have to make do with whatever crappy power is provided. A good thing to have in your gig bag for emergencies, absolutely. But not necessarily the best solution for your studio.

 

 

[Old Joad]

agreed, I did the test and got some results, but when I tried the Hum-X  it didn't work so back to Amazon it goes..