This Damn Noise in the PA When I Plug The Laptop's AC in...

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Post by Guest » Sat Jun 19, 2004 4:52 pm

link: solve ground loop problem

do not cut the ground. it is there for a reason.
otherwise audio manufacturers wouldnt put it at all.

Mehalic
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Re: cut off the ground wire

Post by Mehalic » Sat Jun 19, 2004 6:11 pm

HatHead wrote:
Hi Michael - did ya cut the chord? or get a ground lift? I remember those little grey plugs but think they are no longer available here in Canada due to the CSA.

Thanks and peace 2 all!
[:)
Haven't tried it yet - I seem to remember a friend of mine having a box that he could plug into that would then plug into the outlet for just this purpose. I want to see if I can get my hands on it to see if it will elimate the noise. If this doesn't work, I may have to try some of the things mentioned here. Not sure if the box my friend has is a trans-induction box or whatever, but I have a feeling it will work! I will let everyone know....

And thanks to whoever posted that link to getting rid of ground hum - good info!
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Erik

Post by Erik » Sat Jun 19, 2004 8:45 pm

Queston

I've had this same problem... A/C hum when plugged in, firewire 410, compaq laptop.

I'd like to try to remove the ground pole or bypass it with an adapter but I am worried about the saftey of my equipment if I do this. Could anyone enlighten me to the pros/cons of this approach?

I solved it by getting a hum eliminator. I am quickly finding I need more and more channels of hum elimination because any cord connecting my 410 to a powered external module (input OR output) will create a ground loop. So to run my drum machine L/R into the 410, and then have stereo output into a mixer I'd need 4 channels of hum elimination. Sucks.

Unfortunately, the 2 channel hum eliminator is $60... a much more expensive solution than just bypassing the ground pole on the a/c adapter.

Website w/ hum eliminators:
http://www.sms-mladi.com/Hum-Eliminators/378/1/

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Post by HatHead » Sun Jun 20, 2004 4:14 pm

[quote="Erik"]Queston

I've had this same problem... A/C hum when plugged in, firewire 410, compaq laptop.

I'd like to try to remove the ground pole or bypass it with an adapter but I am worried about the saftey of my equipment if I do this. Could anyone enlighten me to the pros/cons of this approach?

quote]

Hi Erik, thanks for the info - I knew I left room on my rack for something...

I am not an electrician but if you had the surge protection et al. on your power bar, would it then be OK to use an adapter?

Peace!
[:)

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Fixed!

Post by Mehalic » Wed Jul 07, 2004 5:01 pm

Just thought I would let everyone know I did get rid of the ground loop problem by lifting the ground on the laptops plug. I used an old 2 prong extension cord which fits a 3 prong plug leaving the ground exposed - crystal clear now... back to making music!

Thanks for everyones input, mucho appreciated!
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RadioShack To The Ground Loop Rescue!

Post by HatHead » Wed Jul 07, 2004 5:14 pm

I hope all is well with everyone & some good news to share too! Mr. Mango's post reminded to share with you all that I also got rid of my ground loop problem without defeating the ground pin.

$20.00 for a stereo RCA male-to-male cable with a big transformer in the middle of it. Made for CD players and car stereos but it got rid of the ground loop problems for me. (You need one for each connection in-or-out of your audio card to sheild the problem).

http://www.radioshack.ca/estore/Product ... RadioShack

Michael - how did your gig the other week go? I'm giving Live 4 a run through next weekend down by the docks: http://www.hatheadmusic.com/july16.htm

It's an after-hours party and there'll be refreshments available ;) Hope u can make it!

Peace!
HatHead

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Re: RadioShack To The Ground Loop Rescue!

Post by Mehalic » Thu Jul 08, 2004 4:14 pm

HatHead wrote: $20.00 for a stereo RCA male-to-male cable with a big transformer in the middle of it. Made for CD players and car stereos but it got rid of the ground loop problems for me. (You need one for each connection in-or-out of your audio card to sheild the problem).

http://www.radioshack.ca/estore/Product ... RadioShack

Michael - how did your gig the other week go? I'm giving Live 4 a run through next weekend down by the docks: http://www.hatheadmusic.com/july16.htm

It's an after-hours party and there'll be refreshments available ;) Hope u can make it!

Peace!
HatHead
Interesting alternative hathead - although I would love if they had this with 1/4" connections instead of RCA's! I talked to a few people who do gigs regularly, and they were saying this is a common problem, and lowered my concerns about removing the ground. I'm just glad I have clean sound now ;)

Thanks for asking - gig went better than expected for my first live show! Still had the ground loop problem which was pissing me off, but I guess no one else could really hear it (or they were just being nice!!)... Something I want to do again!!

That sounds like fun hathead, nothing going on next weekend, may have to take you up on your offer, especially if your running v4!
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Re: RadioShack To The Ground Loop Rescue!

Post by HatHead » Fri Jul 09, 2004 5:41 am

Mehalic wrote:Interesting alternative hathead - although I would love if they had this with 1/4" connections instead of RCA's! I talked to a few people who do gigs regularly, and they were saying this is a common problem, and lowered my concerns about removing the ground. I'm just glad I have clean sound now ;)

Thanks for asking - gig went better than expected for my first live show! Still had the ground loop problem which was pissing me off, but I guess no one else could really hear it (or they were just being nice!!)... Something I want to do again!!

That sounds like fun hathead, nothing going on next weekend, may have to take you up on your offer, especially if your running v4!
I don't like the RCA's either but I have some goofy adaptors that seem to be doing the trick.

I'll put your name on the list for next Friday's show - hope u can come. Doing a gig as well with live 3 (for some original improv) and traktor (dj'ing) this sat. afternoon at queen's park for Afrofest 2004 - nothing like getting to beat the african drum for a couple thousand people!
Peace!

[:)

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Post by beamsville » Thu Oct 21, 2004 8:14 pm

Don't cut the prong... you'll want the protection that it offers when not jamming.

I've been through this one a few times, so I'm quite sure (assuming that the noise is 60Hz hum, not a digital artefact) that removing the ground pin from the circuit will solve your problem.

As mentioned above, the grey thingy is the easiest solution. Although they don't sell them anymore, any older hardware store should have them for $0.99.

Alternately, you could buy a cheap extension chord, and cut the ground pin off it - that way saving your laptop adapter. The ground pin is the one that isn't flat like the other two.

Don't forget that the ground pin is a safety device, so don't bypass it except when necessary.

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Post by Mehalic » Thu Oct 21, 2004 8:41 pm

Yeah, I ended up using an old groundless extension cord that the audio interface can plug into without the ground, and ever since I've been in heaven - no more hum! YEAH....
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Post by drez » Fri Oct 22, 2004 3:21 am

beamsville wrote: As mentioned above, the grey thingy is the easiest solution. Although they don't sell them anymore, any older hardware store should have them for $0.99.
Radio Shack has em.
http://www.soundcloud.com/dreznicek
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might have the answer.

Post by bass nerd » Fri Oct 22, 2004 7:50 am

So i too had the noise prob. Yes i hate it. I still get it form my amp but hey, I'm still livin.
I went to my local electronics store and picked up a
GROUND LOOP ISOLATER.
Its a rca with this "isolater". It did the trick. Cost me 20 bucks. I wish I had a couple more of them. It's nice to hear some static in the system and be like, "Hey, what is that"? Unplug my comp and still hear the noise coming form some other electronic troube maker.

Soul peace yall.[/b]
HP zx, P4, 3.06GHz, 1GB Ram, MAudio 410. Ableton 4, Reason 2.5, MAudio uc-33, Korg MS 2000

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Post by rEalm » Fri Oct 22, 2004 11:28 am

DON'T CUT THE GROUND PLUG! Just get a ground lift adaptor from someplace online, they're dirt cheap. You can get them at places like Tandy, Radio Shack, etc too.

As for the Indigo not causing noise at home, but possibly in a club, it depends. Most likely if you don't hear any noise at home, you'll be fine once you get to the club, but it's no guarantee. Club's can have notoriously bad power due to all the electrical equipment they are running at once, so it always pays to have a ground lift plug (or 2, play it safe) handy. I was playing in a club that's power was so bad, it was totally freaking out my Emu PX-7, it would restart, made all kinds of strange noises, played the wrong patches, etc. All due to the fact that their lighting rig was on the same power supply as the DJ booth.

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Post by nickw » Fri Oct 22, 2004 3:18 pm

Big article in this months SOS mag on getting rid of solving just these kind buzzes.

Firewire devices are specifically mentioned as being prone to these problems.

They point out (as others have here) that removing the earth pin on a device may get rid of the hum, but is potentially very dangerous.

They detail how to make audio leads that break a ground loop more safely by breaking the earth in the lead, so each electrical device still has its direct route to ground for potentially fatal mains electricity.
Macbook Pro 1.8

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Post by Kas. » Sun Oct 24, 2004 12:11 pm

Tricky problems indeed. I too found that using a ungrounded cable to the laptop worked best. Saftety is indeed a concern but as most laptops use a ungrounded conection between their power converter and the laptop itself I don´t think there is too much risk there. Also; laptops are generally not made of metal on the outside so getting life threatnig shocks from them would be next to impossible. I tought myself to keep my beer and water on the floor and not inbetween the gear, i think falling drinks are the largest danger of shorted serquits in performances.

Just my thoughts, don´t call me from the hospital.

One point where I found not grounding your laptop helps a lot is when you use both a laptop and old analogue gear that still uses grounded plugs (most modern gear doesn´t), i found that particularly my old delays will output this same noize you hear from the soundcard when grounded to the same ground as the laptop. Very, very anoying.

As for clubs; sometimes the electricity there is so bad it´s almost unbearable, particularly the smaler, less profesional ones. At one time the resque was running a long powercable to the local kitchen which had it´s own group. At least you can be sure kitchens have a proper ground for those boxes that need one. As always; tape down such a cable with enough tape to cover a small country. D.I. boxes also help, occasionally, sometimes they make it worse. try to keep them at hand if possible.

This radio shack rca adapter looks like it´s worth a try but I´m in europe (netherlands) does anybody know of a easy way to get one here without bothering my canadian friends?

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