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Topic: 112 XLR hum? |
Chris Brooks
From:
Providence, Rhode Island
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Posted 15 Jun 2017 11:03 am |
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My Peavey 112 XLR output puts out a hum when connected to a board . . . sounds like 60 cycle. I've tried various cords in several locations and hook it up to my little Behringer PA: hum is still there.
I have shows next week where the sound man likes to run direct outs. I could use another amp, but I like my 112!
Is it amp-tech time?
Chris |
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Lane Gray
From:
Topeka, KS
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Posted 15 Jun 2017 1:58 pm
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It might be a ground loop issue
_________________
2 pedal steels, a lapStrat, and an 8-string Dobro (and 3 ukes)
More amps than guitars, and not many effects |
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Jack Stoner
From:
Kansas City, MO
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Posted 15 Jun 2017 2:04 pm
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| Some XLR cables have the ground (shield) connected at both ends and that can cause hum. Disconnecting the ground on one end (either end, doesn't matter) will cure that specific problem. |
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Ken Fox
From:
Nashville GA USA
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Posted 15 Jun 2017 5:55 pm
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I am sure both are right. To quickly check that before doing surgery on the mike cable you can use a ground lift plug on the amp. A temporary usage only! If the hum goes away it is indeed ground loop hum. Another solution is to use a Hum-X by Ebtech on the end of the power cord
In pro audio I was taught to remove the ground at the audio source (the amp) on the mike cable, the shielded cable would then be connected at the mixer only.
https://www.amazon.com/Ebtech-Hum-Voltage-Filter/dp/B0002E4YI8
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Justin Griffith
From:
Taylor, Texas, USA
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Mike Wheeler
From:
Delaware, Ohio, USA
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Posted 19 Jun 2017 4:42 pm
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Ken has, once again, given sage advice. Lifting the ground at the "source" end of the cable will give the best results.
I, too, learned this many years ago from some of the industries top sound engineers.
_________________
Best regards,
Mike |
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Bill Ferguson
From:
Milton, FL USA
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Posted 20 Jun 2017 6:39 am
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Many times when I was doing sound for some of the larger steel shows, direct out hums would drive me crazy.
Instead of using the XLR outs, I finally started using Direct Boxes (that have a ground lift switch) and plugging out of the PreAmp out.
Solved the problem 95% of the time.
_________________
AUTHORIZED George L's, Goodrich, Telonics and Peavey Dealer: I have 2 steels and several amps. My current rig of choice is 1993 Emmons LeGrande w/ 108 pups (Jack Strayhorn built for me), Goodrich OMNI Volume Pedal, George L's cables, Goodrich Baby Bloomer and Peavey Nashville 112. Can't get much sweeter. |
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Chris Brooks
From:
Providence, Rhode Island
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Posted 20 Jun 2017 11:25 am
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Thanks, guys, for these good ideas.
I have convinced the sound man, too, to simply mike the amp, as Justin suggests. Makes sense because, after all, the "sound" is a combination of the electronics, the speaker, and even the cabinet, right? And I believe there's a "best spot" of the speaker to point the mike at . . .
So we're going to loop the mike cord through the handle and dangle the mike in front of the speaker.
I am not an electronics guy. Heck, I can barely play this thing!
Chris |
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