ID and destroy hum

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Zef
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2009/02/13 23:38:26 (permalink)

ID and destroy hum

I need help, if anyone can...
I'm not a connoisseur of "hum noise" so any help would be great... I'm pretty sure its ground hum, but I just want to be sure.

Hopefully you can confirm its ground hum, and also that it is cheap to defeat.
Any help rox!
Thanx
~Seth
post edited by Zef - 2009/02/16 04:13:02
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15 Replies Related Threads

    The Maillard Reaction
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    RE: ID and destroy hum 2009/02/13 23:59:29 (permalink)
    It's hum from bad grounding... but it's not a ground loop.
    The shielding on your guitar, pickups, control cavity, cords, and perhaps efx pedals is not adequate for the enviroment you are recording in.

    Your guitar rig is acting like an antenna and picking up noise... perhaps flourescent lights, a television, a computer monitor, your blackberry?

    The high gain style of your effects stack is emphasizing the noise.

    Personally I think the buzz is really helping with the whole vibe... I wouldn't change a thing :-)

    best,
    mike


    #2
    Zef
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    RE: ID and destroy hum 2009/02/14 00:12:14 (permalink)
    THANX!
    Just wanted confirmation before I ran out to buy a few thousand $ worth of stuff.

    Would a Ebtech unit like this help?
    http://www.americanmusical.com/Item--i-EBT-HE8-LIST

    Could a cheaper unit defeat this?
    Thanx herds!
    ~Seth
    #3
    The Maillard Reaction
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    RE: ID and destroy hum 2009/02/14 08:55:16 (permalink)
    I don't think a Ebtech will help because you have insufficient shielding. The shielding is supposed to be connected to ground so that any stray EMI or RFI that hits it gets sunk in ground rather than joining your audio signal.

    An Ebtech is a gadget meant to help people who have decided they need to buy a gadget rather than needing to learn how to properly patch a system. Every now and then someone who knows how to eliminate ground hum at the source may find a gadget like the Ebtech expidient and useful E.G. when interfacing with an existing system where there is no practical option to repatch someone else's equipment that you are working with.

    In any event the hum you are hearing is not from bad grounding... it's from insufficient shielding or shielding that is not effectively connected to ground.

    Why don't you describe your guitars signal chain... maybe there is an obvious issue that could be solved.

    Guitar? What pickups? Shielded Cavity? Guitar cord? pedals? If any? Gain chain... real amp or sim? etc etc

    best,
    mike


    #4
    Zef
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    RE: ID and destroy hum 2009/02/14 09:18:56 (permalink)
    THANK YOU SO MUCH for the help! and quick reply!

    This is a pic of one of my guitar racks... the one I use most often.
    [image] [/image]

    Pod XTpro
    Behringer dual chan 31 band EQ
    " Dual chan exciter
    " Tube pre
    " Comp/lim/gate
    ART SP 9 chan power conditioner.

    The hum comes and goes as I move the guitar around... and also when ALL I have plugged in, is the POD xt Pro.
    I used the "ground lift" on the back of the XT pro... it shows me no love.

    To be clear, I've removed EVERYTHING else from the socket... its a "single" line nothing else was on it but my guitar and the Pod XT pro.

    I do believe the socket/s here are NOT grounded... but since I'm in a place renting right now... It would not be worth it for me to have someone come in, and ground the place for $X amount.

    Any possible way that just a REALLY long cord.. or REALLY expensive gold monster cable or some other CHEAP means can be resorted to? The Pick ups on the Ibanez are ACTIVE... I'd had to believe they are shielded. though, the sound would seem to dispute that... lol. The plastic electronics covers are shielded...

    Would copper tape help?

    Any chance that all those games I played as a child about who could hold their finger in the powered empty lamp socket longest, might have something to do w/ this? LMAO!

    For real, thanx herds!!
    ~Zef
    post edited by Zef - 2009/02/16 04:13:24
    #5
    Zef
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    RE: ID and destroy hum 2009/02/14 09:23:41 (permalink)
    i
    post edited by Zef - 2009/02/14 09:24:15
    #6
    The Maillard Reaction
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    RE: ID and destroy hum 2009/02/14 11:12:57 (permalink)
    "The hum comes and goes as I move the guitar around"

    It seems to me that the guitar is clearly the antenna. If it's active and the batteries are fresh than most of the noise is probably entering at the guitar rather than along the cables... but you can certainly try fresh cables

    All that Behringer stuff with the plastic jacks may also exasperate the issue as it's unclear how the chassis ground on each of those appliances is connected... the chassis may not make for good shields.

    It also possible that your string ground on the guitar has gone bad... so your strings are also part of the antenna.

    I have a Jazzmaster that knows if my wife is watching TV in an other room :-)

    The most practical thing for you to do (if you don't find a lose ground in your guitar and cables) is just to stay away from the source of the noise. Turn off the TV, the flourescents, etc.

    Otherwise you need to search down all the shielding connections and make sure they are adequate and in good repair. I'd check the pickup cavities, the guitars string and bridge ground, the cords etc etc etc.

    Also If you really only have two prong wall outlets MAKE sure that you are connecting the "cold" to "cold" (don't casually turn a 3 to 2 prong adapter "over") because the chassis ground of each appliance in your rack (which is the shield for your appliances) is depending on being connected to ground via the "cold" wall outlet to provide a connection to ground. Make sure the polarity of each appliance is correct .

    best regards,
    mike



    #7
    kwgm
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    RE: ID and destroy hum 2009/02/14 11:30:46 (permalink)
    You know why amplifiers hum, right?

    ('cause, they don't know the words, naturally.)

    Here's an excellent article on hum, shielding, etc. (from a real live engineer!), that I like to share when people have this problem. Read it (there'll be a quiz after), and it should answer your questions.

    Rane (Click this link)


    --kwgm
    #8
    Zef
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    RE: ID and destroy hum 2009/02/14 14:25:19 (permalink)
    Thanks for the info! Will def read.

    Don't know how relevant this might be to mention, but I used a Circuit tester.
    [lil yellow thing with three lights and three prongs. ]

    I plugged it in and ALL the socket in my recording room are "Open ground".
    Since I'm renting, I'm not about to pay to get all these grounded...

    This is making me nuts... For months, I've just gotten mad every time I plug in! lol.

    I know its "cheating" but are there any rack mount type power conditioners anyone knows of, that would help with this? Ive read "rave" reviews about the Ebtech stuff... but I'm not sure its going to work in this instance. I've checked the ground on my guitar... looks ok.

    Any thoughts on units to help with this?
    Thanx.
    ~Zef
    #9
    Guitarhacker
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    RE: ID and destroy hum 2009/02/14 17:10:19 (permalink)
    if the hum comes and goes..... see where it is the strongest. I can get that kind of noise when my amp gain is really cranked (as in distortion mode) and also if the guitar is near my old monitor. I now have a flat screen so that is no longer an issue. But I agree....the guitar is picking up this noise from something in the environment.

    The more gain you crank on a guitar/amp combo, you will eventually get the noise levels cranked pretty high too. then come near a monitor, or a power amp transformer and there you have it. Major noise.

    HTH...

    My website & music: www.herbhartley.com

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    #10
    The Maillard Reaction
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    RE: ID and destroy hum 2009/02/14 22:09:47 (permalink)
    First since you're renting... the property owner should have your open grounds fixed immediately... especially if the wall sockets are 3 prong and just not connected properly.

    If this is the case all bets are off... It's one thing to use a 2 prong AC appliance safely and an entirely different thing to have appliances that are designed with a need for a ground connection that not actually connected to ground.

    It's unsafe to lift the ground... I can speak from experience :-)

    Not only do you have a safety problem but any of the devices in your rack, your amp, and your guitar can now be considered to be unshielded antennas because most of the chassis grounds are apparently floating and are not connected to any ground.

    good luck,
    mike



    #11
    Cromberger
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    RE: ID and destroy hum 2009/02/16 04:35:29 (permalink)

    ORIGINAL: mike_mccue
    An Ebtech is a gadget meant to help people who have decided they need to buy a gadget rather than needing to learn how to properly patch a system.


    Hi, Mike,

    Well, you are probably right about that but, then, there are those of us who are simply too lazy to run down the ground loop problem. When I got my Mackie 824's I plugged them in and found that I had a grounding issue---I was getting hum like crazy. But I wanted to listen to my new speakers, not trace ground loops, so I slapped an Ebtech Hum Eliminator between my interface and the Mackies and had instant satisfaction. I'd had the Ebtech sitting around unused for years. To this day I've got the damned Ebtech in the circuit because I've just been to lazy to fix the real problem. And I freely admit that I'm not likely to change this arrangement anytime soon. ;>)

    To anyone reading this: Mike is, of course, correct; Don't use an Ebtech to solve this sort of problem. You're way better off fixing it at the source. Don't be a lazy good-for-nothing like I am and let a little box solve the issue for you. ;>) In other words, don't try this at home......

    Best regards,
    Bill

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    #12
    edentowers
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    RE: ID and destroy hum 2009/02/16 06:57:22 (permalink)
    Good thing you Americans don't have the 240 volts that we Europeans have.

    This thread is VERY scary.

    I plugged it in and ALL the socket in my recording room are "Open ground".
    Since I'm renting, I'm not about to pay to get all these grounded...


    Can you run an extension cable from a room where the ground IS connected?

    S8PE, Dell XPS 720 (Q6600), XP Pro SP2, Edirol UA-101
    #13
    The Maillard Reaction
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    RE: ID and destroy hum 2009/02/16 08:40:32 (permalink)
    ORIGINAL: Cromberger


    ORIGINAL: mike_mccue
    An Ebtech is a gadget meant to help people who have decided they need to buy a gadget rather than needing to learn how to properly patch a system.


    Hi, Mike,

    Well, you are probably right about that but, then, there are those of us who are simply too lazy to run down the ground loop problem. When I got my Mackie 824's I plugged them in and found that I had a grounding issue---I was getting hum like crazy. But I wanted to listen to my new speakers, not trace ground loops, so I slapped an Ebtech Hum Eliminator between my interface and the Mackies and had instant satisfaction. I'd had the Ebtech sitting around unused for years. To this day I've got the damned Ebtech in the circuit because I've just been to lazy to fix the real problem. And I freely admit that I'm not likely to change this arrangement anytime soon. ;>)

    To anyone reading this: Mike is, of course, correct; Don't use an Ebtech to solve this sort of problem. You're way better off fixing it at the source. Don't be a lazy good-for-nothing like I am and let a little box solve the issue for you. ;>) In other words, don't try this at home......

    Best regards,
    Bill



    Hi Bill,

    You can sense my dislike for the Ebtech solution... so let's be honest about that :-).

    My frustration is with the fact that people seek out an an isolation transformer (e.g. Ebtech) solution when a better solution is almost always to simply use an appropriate extension cord and a little bit of knowledge.

    An extension cord is a cheaper, better, and safer solution and does not perpetuate the idea that a gadget can allow one to ignore and avoid solving a simple issue.

    The few times that an Ebtech is the best solution is when you are forced to work with a badly installed house system that you can't repatch or the equipment itself was so poorly designed that proper wiring causes ground loops... both are less than common scenarios.

    In your setup the Ebtech seems to have made your life easy and pleasant. My guess is it would take about 10 minutes to have solved the problem without spending for the ebtech AND you (Bill, FWIW I know you're already a seasoned old timer with lots of skills) would have the skill down so it would be even quicker next time :-).

    Personally when I need a isolation transformer I go for the premium stuff... Jensen isolation transformers... that way you can actually see the specs of the gadget you're using rather than just being assured of "audiophile" quality ala Ebtech. :-)

    In the OP's situation, purchasing and installing an unnecessary isolation transformer will just perpetuate the unsafe conditions he is working in... and that's the very worst situation a "gadget mentality" can get you into.


    All the best,
    mike
    post edited by mike_mccue - 2009/02/16 08:43:52


    #14
    Cromberger
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    RE: ID and destroy hum 2009/02/16 22:16:49 (permalink)
    ORIGINAL: mike_mccue

    You can sense my dislike for the Ebtech solution... so let's be honest about that :-).

    Of course. And you entirely, unquestionably right. I was just giving you a tongue-in-cheek, smart-ass reply. No offense intended. When I was a kid my family constantly told me that my "smart mouth" would get me into trouble. They were absolutely correct.... ;>)

    My frustration is with the fact that people seek out an an isolation transformer (e.g. Ebtech) solution when a better solution is almost always to simply use an appropriate extension cord and a little bit of knowledge.


    I couldn't agree more.

    An extension cord is a cheaper, better, and safer solution and does not perpetuate the idea that a gadget can allow one to ignore and avoid solving a simple issue.


    Ditto.

    In your setup the Ebtech seems to have made your life easy and pleasant. My guess is it would take about 10 minutes to have solved the problem without spending for the ebtech AND you (Bill, FWIW I know you're already a seasoned old timer with lots of skills) would have the skill down so it would be even quicker next time :-).


    Once again, you are entirely right. I only slapped the Ebtech on because I happened to have it sitting around unused for many years. I knew it would "solve" (not really, of course) the problem so I could listen to my new Mackies. I was a bit impatient...... It's a sad comment on how remarkably lazy I actually am that the Ebtech still resides in the circuit. I *really* must deal with that one of these days real soon. ;>)

    In the OP's situation, purchasing and installing an unnecessary isolation transformer will just perpetuate the unsafe conditions he is working in... and that's the very worst situation a "gadget mentality" can get you into.


    Oh, my, I don't *think* I recommended that the OP invest in an isolation transformer, I was just, as I said above, making what I intended to be a humorous reply to your post. If I left the impression to the OP that I was suggesting a transformer as a solution to his/her problem, then I apologize profusely to both the OP and anyone else reading this thread. Not my intent at all. I would certainly never suggest that anyone purchase an isolation transformer to solve this kind of issue. However, I have, from time to time, said that such a device can help in troubleshooting hum issues *if* one should have one sitting around, as I did. But as an ultimate solution? No way.

    Best regards,
    Bill

    Edited for typo


    post edited by Cromberger - 2009/02/16 22:24:10

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    The Maillard Reaction
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    RE: ID and destroy hum 2009/02/17 07:14:06 (permalink)
    Bill,

    I don't think you recommended that the OP do it either. I hope no one else reading this thought I said that you were doing so. :-)


    Like I said, I know and appreciate that you are a seasoned musician and sound person.

    very best,
    mike


    #16
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