Microphones getting shocked by mics

[howlingwolf487]

Here's that link I promised - much thanks for Kemper Watson on PSW for his help finding this thing.

Don't Kill The Artist - Roadiepedia

You can also download the PDF version - there's a link on the same page.

 

[KProductions]

That's a great article.

UPDATE. I went through the system and made sure all the grounds were correct. I found that the removable plug from the main mackie VLZ console only had 2 prongs on it. We had let someone use the system a few weeks ago and they changed the cord that is kept with the rack. New 3 prong cord,... all grounds correct,.... no shocks, and clean, quiet, hum free system (although a scene change with the installed PAR lights caused a "static" sound through the speakers). A new problem for another thread perhaps...??

Thank you everyone for your great advice.

 

[waynehoskins]

Wayne, - I think you hit the nail on the head. The guitarist WAS using an older tube head - and this seems to be the difference between this band and the others that have used the system.

So let me get this right. Although his "amp" was properly grounded via the three prong plug, - his amp "chassis" still needs another ground...??

Should this happen again, I'm sure the guitarist will not let us take his amp apart and remove capacitors. How do I Earth the chassis of the amp on the fly right before showtime..??

Thanks,...

The trick I've used is to take an Edison plug and a length of wire, connect the wire to the ground pin, and strip the other end and somehow bond it to chassis. It could be lifting a screw; I've also taped it to the shell of the guitar cable before. If it's an AC-DC set where one side of the line is tied to chassis, then you have to be careful which way you plug it in -- wrong way with a grounding wire and you short out your hot coming in -- but that's pretty rare these days.

If his amp had a ground already, then something else is probably not right.