Hum Eliminators

Lefty Schrage · Post by **Lefty Schrage** » 25 Jun 2001 6:42 am

I'm using two amps and occasionally get a disturbing hum due to ground loops. I'm aware that a ground lift shouldn't be used due to the danger involved. I just ran across a device in 'Musicians Friend' called the 'Ebtech 2 Channel Line Level Shifter' which the mfr claims will break ground loops, i.e., the unit)"...contains Ebtech's Hum Eliminator® technology to break ground loops." Have any of you tried this device? Does it effectively eliminate the hum created by ground loops without lifting the ground? ...Lefty

Fred Murphy · Post by **Fred Murphy** » 25 Jun 2001 11:39 am

I have two of them and yes they do work. It won't solve any hum problems from your effects or amplifiers, just the ground hum.

Keith Hilton · Post by **Keith Hilton** » 25 Jun 2001 12:16 pm

Lefty, most of them use a isolation transformer. They won't cure cancer, but they do help in some situations. Ground loops are only one of many problems that can cause hum. Don't streach cords over anything that creates a electronic field around it. Something as simple as having your effect units too close to your pickup can cause hum.

Craig A Davidson · Post by **Craig A Davidson** » 26 Jun 2001 7:06 pm

Lefty, If you would teach them the words, Buddy, they wouldn't have to hum. How you doing? Long time, no see.

------------------
1985 Emmons push-pull, Session 500, Nashville400, 65 re-issue Fender Twin, Fender Tele

Lefty Schrage · Post by **Lefty Schrage** » 27 Jun 2001 4:33 am

Howdy Craig! Are you still humming a lot of the words? Good to hear from you. ...Lefty

Ed Miller Jr · Post by **Ed Miller Jr** » 27 Jun 2001 4:46 pm

Lefty, glad to see that your still out there! If you get to Coldwater stop by the store..I'll probably still be there.

Ed MIller

Lefty Schrage · Post by **Lefty Schrage** » 28 Jun 2001 11:34 am

Hi Ed - Good to hear from you, too! We may get out your way late summer or sometime in the fall. If we do, we'll be sure to stop by. ...Lefty

Chris Schlotzhauer · Post by **Chris Schlotzhauer** » 28 Jun 2001 11:48 am

Lefty,
I know you said you don't want to use a ground lift, but if you simply put a lift on one of the amps, and not the other, that should clear it up. What is your concern when you say "danger?"

Lefty Schrage · Post by **Lefty Schrage** » 28 Jun 2001 1:07 pm

Hi Chris - Altho' I frequently used ground lifts for a period of time, I discontinued this practice after reading one of the a previous threads on the Forum that explained how doing a ground lift makes a performer vulnerable to electrical shock under the right conditions; for example, if a short circuit would occur and the house system isn't properly grounded, the ungrounded electrical current could very possibly pass directly through the performer. ...Lefty

Jim Smith · Post by **Jim Smith** » 28 Jun 2001 1:39 pm

I thought the ungrounded amp got it's ground from the other grounded amp. It's the two grounds working against each other that causes the hum.

Buck Dilly · Post by **Buck Dilly** » 28 Jun 2001 6:15 pm

Ditto what Jim said. Only one ground in a signal chain is going to be needed.

Bill Terry · Post by **Bill Terry** » 29 Jun 2001 7:51 pm

This is pretty informative.... http://www.epanorama.net/documents/groundloop/index.html
According to this info, if you lift ground on one amp, you potentially force system (amplifier) ground of the ungrounded side through the shield of whatever cables connect the two devices. Not good...

------------------
Home Page

Bob Cox · Post by **Bob Cox** » 8 Jul 2001 11:28 am

Where do you by the ground lifts? We have a guitar,plugged into a pa, at a club we are playing in, that is humming like a kawasaki? <FONT SIZE=1 COLOR="#8e236b"><p align=CENTER>[This message was edited by Bob Cox on 08 July 2001 at 12:30 PM.]</p></FONT>

Ernie Renn · Post by **Ernie Renn** » 8 Jul 2001 4:35 pm

Jeff Newman said that in your system, (amp, effects, etc...) you should have one ground. Everything else should be lifted. I have tried this and it does seem to eliminate the hum. However, if your directly connected to the snake to go to the main mixer, you still might have the same hum because of the connections of the rest of the band.
We played a gig a few weeks ago and there was an incredible hum. We tried this approach. We lifted everything but the biggest power amp. It worked. Go figure.
It might be a bad thing, but it did get rid of 95% of the hum.

------------------
My best,
Ernie

The Official Buddy Emmons Website
www.buddyemmons.com