[capnvic]

Originally Posted by madjim

Hey Billy,
You are correct here. I did not reccomend that Karl keep using the 3 to 2 prong adapeter. Using the adapter like Bob suggested only determined that Karl has a gound loop issue. The ground should ALWAYS be used like Lonnie said, or somenbody is going to get bit on the lip when the current flows to ground from the mike, to their lip, through their body, to the floor which is now the system ground. I felt this once working on somebody eleses system and it was very painful. It actually split my upper lip open. I never let it happen again.

I have found that if every peice of equitment used in a sound rig is plugged into only one outlet there is no need for any kind of hum eliminator. I've been setting up my gear in clubs for over 25 years now with no system hum or buzz and have never had to use a "power hum eliminater". I make sure everything is plugged into one outlet and there is no 60 cycle system hum. (I'm sure "power hum eliminaters" work, I've just never had to use one. )

If I had a hum (it normally comes from a guitar amp which I don't use in my shows since my band died years ago) I use a Direct Box and lift the ground on the input that is causing it. I guess you could call a DI box a hum eliminater but it lifts the ground from the input going into the mixing board. I don't like to mess with my power ground ever since I got bit on lip.

Now rooms with alot of light dimmers installed can cause a hum. In this case a "power hum eliminater" may be handy but I've never had a room with dimmeres be so bad that I could not do a good show. If your ground sceme is correct, the hum will be very low in volume and only noticable during total silence. The dimmers are normally turned down for the show anyway.

Karl,
If plugging all of your gear into one outlet does not eliminate your hum them by all means get a "power hum eliminator" or a Direct Box, I suggest you use a Direst Box.

Thanks Everybody!

Jim

I find that a rack mounted power conditioner seems to take care of everything. I have never noticed a power hum on any of my rack mounted devices. Some of these units have some kind of filtering added to them.