Ground Loop Isolators Messing Up Club Circuit?

I am using 4 ground loop isolators on all my 4 channels going from the Audio8 into the mixer to get rid of the noise which my notebook power supply creates. I only have a very rough idea of how these isolators work so some decent technical insight would be nice here.
So... last night I had some major incidents with a club's power circuit. It started with a drop-out of sound (for about half a second) when I used the fog machine. Later on, after using the fog machine a few times without any problems, at releasing the pushed button of the machine my soundcard would... stall(?). I had to reconnect it and gladly Traktor continued directly where it left off after a few seconds of silence but this was awkward.
About 30 minutes later the circuit fuse blew! And this totally came out of nowhere. No fog-machine this time.
According to another DJ this has happened before but I am not sure if the club owner knows this as he seemed very surprised when I rushed to him.

So what was going on there? Could my isolators cause any of these problems? Or was this just a classic case of weird fog machines or bad wiring?

No , isolators wont cause this in my opinion. Ive used them in a similar way for years.

Fog machines draw a lot of power as they have a heating element. This sounds like bad wiring probably.

I would try to find a way of getting all your gear on a different section of the ring to the fogger and use circuit breakers that provide surge protection.

Im no expert though but experience of playing in shitty UK venues has taught me all i know. Never use the same mains wall adapters as the foggers/lights etc and always use surge protection.

Like i say im no expert and i dont even know the correct terminology but all the "know how" in the world is no substitute for experience inmho.

K

Could the USB cable between the computer and the sound card also cause this? As all the problems seem to be global and not on any one channel, this is what I came up with.

Phil.

This sounds more like shoddy wiring in the club than problems with your GLI. I've been using mine now for 2 years and never had a problem with it.

Totally agree. Looks like your club has some wiring issues. But using a GLI when it's not needed can sometimes cause you to get a buzz. What you're describing is different than that.

so... I know you are a dj, and are technically not suppossed to be up in the sound mans buiness, but........

How many watts of power does the sound system draw?
How many/ what type amps does the place have?
Is the sound system all on one breaker?
Is the fog machine on the SAME breaker?

a conventional 15 amp circuit puts out in the range of 1800 watts. Most fog machines are around 1000-1500 watts themselves, and I assume you have about 4k watts of sound or something like that. All of that on the same breaker = saddddd breaker. especially if you were hammering some DnB or something out (sub amps draw a lot more power to make equivalent volume)

There is also a much simpler (and cheap) way of isolating your laptops mains power supply.

To save you using 4 isolators, simply make up a short extension cable using 2 core cable (no earth) and plug your laptop into the extension, and the extension into the mains.

Instead of 4 isolators in your soundcard, why not have just one coming out of the mixer output?

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Originally Posted by Karlos Santos

No , isolators wont cause this in my opinion. Ive used them in a similar way for years.

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Originally Posted by R-Presley

This sounds more like shoddy wiring in the club than problems with your GLI. I've been using mine now for 2 years and never had a problem with it.

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I'm really glad to hear this, thanks. I was a little worried that it might have been my fault.

About the actual connections, I will ask them next time I get there but from what I got yesterday the amp isn't on the same circuit; just the mixer and fog machine and the sound dropped out because the mixer shut down. I am not 100% sure on this, though.

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Instead of 4 isolators in your soundcard, why not have just one coming out of the mixer output?

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The mixer functions as a small amplifier (pre-amp) itself so it already blends in the ground noise into the output signal in a way it cannot really be filtered out. So the noise has to be removed before the signal is processed.

If its a particularly beefy fog machine, it could take down a crap 15 amp breaker.

I assume the club has one, or 2 50 amp breakers for their amp channels (if they are smart).

instead of putting the ground loop isolators on your rca cables, why not put one on your power cable? Or you can just lift the ground on the power.. Apple laptop power supplies even have a 2 prong adapter you can use...

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Originally Posted by Shane

instead of putting the ground loop isolators on your rca cables, why not put one on your power cable? Or you can just lift the ground on the power.. Apple laptop power supplies even have a 2 prong adapter you can use...

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Yeah, I noticed Apple notebooks don't have that issue and an isolator for the power supply would probably the best solution but I couldn't find anything like that.

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Originally Posted by djmoonie

There is also a much simpler (and cheap) way of isolating your laptops mains power supply.

To save you using 4 isolators, simply make up a short extension cable using 2 core cable (no earth) and plug your laptop into the extension, and the extension into the mains.

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is this safe?

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Originally Posted by zimfella

is this safe?

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no, if the laptop power supply has 3 pins it could have a metal casing. if a malfunction is happening and the casing is under voltage the ground pin prevents current flow when touching it by pulling the case onto earth potential.
the easiest thing to do would be buying a power supply with 2 pins, these are most likely made out of plastic and not conducting.

but no way ground loop isolators can cause fuses to blow, it's most likely the current draw from the fogger which interrupted the laptop or soundcard power for a very brief moment causing the freeze. that's why you should use different circuits for sound and light if possible.
the heating part is where most current is drawn, that is either after the button is pressed and new fluid needs to be heated or if the fluid has been heated but the fogger wasn't used so it needs to reheat.

yeah. basically, he hits the button on the fogger. It turns the heating coil on for a sec, causes the breif drop out. A little while later, the fogger turns the heating coil up to reheat and boom, audio is gone.

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Originally Posted by jinx

no, if the laptop power supply has 3 pins it could have a metal casing. if a malfunction is happening and the casing is under voltage the ground pin prevents current flow when touching it by pulling the case onto earth potential.
the easiest thing to do would be buying a power supply with 2 pins, these are most likely made out of plastic and not conducting.

but no way ground loop isolators can cause fuses to blow, it's most likely the current draw from the fogger which interrupted the laptop or soundcard power for a very brief moment causing the freeze. that's why you should use different circuits for sound and light if possible.
the heating part is where most current is drawn, that is either after the button is pressed and new fluid needs to be heated or if the fluid has been heated but the fogger wasn't used so it needs to reheat.

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I thought computers (I admit laptops may be different) relied on a certain amount of Earth Leakage to operate smoothly anyway. I suppose it could depend on your countries wiring code, but I would certainly not suggest anyone wires a 2 core supply to anything that is meant to be earthed.

We advise any company who are running more than 4 PC's on a single circuit not to protect them with an RCD because of the risk of tripping.

Yup as above that is not your isolators - just a poorly wired club causing surges which is fucking with your shit, long poorly routed cables form an inductance, inductors resist change in flow of current (turn the smoke machine on or off) by producing a voltage spike in the opposite polarity, this spike can cause issues with any nearby equipment running of the same circuit.
I also highly recommend not ever removing earth from a power supply that was designed to use

I am an electrician as well as a dj. you have two problems I would think. Problem 1 the fogger should be on a dedicated circuit I would use a 20 amp circuit for this. Your dj equipment and computer should be on a dedicated circuit also I would use a 20 amp circuit for this as well. Dont know about the wattage about your amps but i d look at that as well. Not enough power going to these and the circuit will pop. Problem 2 something in your setup. cant help you there cause i dont know your setup. Never remove an earth ground. if you have a faulty mixer or something else you will get a nasty shock. another possible problem. a bad ground. run a wire from a cold water pipe to your outlets. this problem causes interference with your sound but this is a problem with the ground of the entire building and is just a quick fix. Get an electrician and explain your setup better and you will get better help

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Originally Posted by Archies'bald

I thought computers (I admit laptops may be different) relied on a certain amount of Earth Leakage to operate smoothly anyway. I suppose it could depend on your countries wiring code, but I would certainly not suggest anyone wires a 2 core supply to anything that is meant to be earthed.

We advise any company who are running more than 4 PC's on a single circuit not to protect them with an RCD because of the risk of tripping.

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That's not a problem. Some laptops come with a 2-pin (without ground) power supply regularly, for example the macbook.

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Originally Posted by midifidler

I also highly recommend not ever removing earth from a power supply that was designed to use

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Ye, that doesn't sound reasonable and I'm not going to do anything like that.

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Originally Posted by jimsimp59

Problem 2 something in your setup. cant help you there cause i dont know your setup.

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I'm on a Sony Vaio notebook using an Audio 8 DJ and several MIDI controllers. So it all runs on USB power. The soundcard's 4 channels are then connected to the club's mixer (DJM-600).

http://www.electronicplus.com/images/products/419GY.jpg

easy solution to power adapter problem.

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Originally Posted by jinx

That's not a problem. Some laptops come with a 2-pin (without ground) power supply regularly, for example the macbook.

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this is interesting because the macbook comes with two "heads" a 2 prong and a 3 prong.. regardless the laptop it self isn't grounded, the power going into the actually laptop is TS..

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Originally Posted by Shane

this is interesting because the macbook comes with two "heads" a 2 prong and a 3 prong.. regardless the laptop it self isn't grounded, the power going into the actually laptop is TS..

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sorry i don't have a macbook myself, i just read it in this thread that is has two pins. however several friends have laptops with a two-pin charger.
probably the macbook has the pin only for easy plug-in but the ground pin isn't connected to anything inside the charger.

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Originally Posted by Shane

this is interesting because the macbook comes with two "heads" a 2 prong and a 3 prong.. regardless the laptop it self isn't grounded, the power going into the actually laptop is TS..

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Yeah if you live in America. Remember things are different in Europe, even more so in UK. Only 3 prong over here.

I cant believe this thread. 8 million answers all saying the same on a such basic issue as Group Loop Hum, mind boggling:D

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Originally Posted by Karlos Santos

Yeah if you live in America. Remember things are different in Europe, even more so in UK. Only 3 prong over here.

I cant believe this thread. 8 million answers all saying the same on a such basic issue as Group Loop Hum, mind boggling:D

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I was more intrested in the people saying that it's deathly dangerous to remove the ground, but from my understanding, laptops aren't even grounded, only the power brick it self when it has a 3rd prong...

There are 2 prong power cords on many generic aftermarket power supplies for various laptop makes. Works a treat, and you aren't being your own electrician.

I carry one in my bag in case I encounter the noise issues. Some places it happens, some it doesnt.

As far as the ground pin removal technique, I've heard some folks say you're crazy to do it, some say they've been doing it in venue sound for years. I've also talked to an electrician about it and he said that if anything does happen the venue will short out at the fuse box "so you should be alright"... :s

I really feel like a geek when I read all of the posts and am completely enthralled by all of them...Of course my response will be redundant so I'll just save it haha

Ground Loop... 2 questions.

Will it help to put a ground cable between the mixer and the Audio 8 DJ soundcard? (use the ground connectors for the turntables).

If you connect the Audio 8 DJ ground connector to ground on the power socket, will it help or destroy the equipment?

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Originally Posted by lourma

Ground Loop... 2 questions.

Will it help to put a ground cable between the mixer and the Audio 8 DJ soundcard? (use the ground connectors for the turntables).

If you connect the Audio 8 DJ ground connector to ground on the power socket, will it help or destroy the equipment?

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The Ground Pin on the Audio 8 is for connecting the ground leads on the turntables should they not reach the mixer or there isnt enough contact for a safe grounding.

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Originally Posted by oliosky

I've also talked to an electrician about it and he said that if anything does happen the venue will short out at the fuse box "so you should be alright"... :s

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Dude how can that be called "alright". Any good Club owner would fire your ass out the building if you short his fuse box out cus you snapped the ground pin off.


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Its real simple. Removing the ground pin from anything is stupid.

Doesnt matter that someone may have been doing it for years with no problems.
Christ my Grandad smoked for 80 years, that doesnt make smoking harmless.

Its whacky and irresponsible. You might not get a shock you sure as hell put all your data as risk if the circuit goes whizzing around your laptop.

Electricians dont use sensitive laptops. Electricians get lots of electric shocks just like carpenters get cuts.


Ive seen this discussion many times and there always people that try to use some half cocked knowledge to fool the other people who may not be so well informed. Dont believe it.
Also consider this. If removing the Ground Pin stops the Hum, then its playing some part in the equation then isnt it.


Its one thing to do its yourself but its another to be irresponsible and recomend that someone else (less experienced maybe) should remove the ground pin.

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Originally Posted by Karlos Santos

Dude how can that be called "alright". Any good Club owner would fire your ass out the building if you short his fuse box out cus you snapped the ground pin off.


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No fucking kidding bro. Hence the ":s" after the quote. Back off there sweetheart I wasn't promoting snapping off a ground pin. I was suggesting getting a suitable aftermarket 2 pin power lead.

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Originally Posted by oliosky

":s" .

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LOL ok petal, ive no idea what :s means, it sounded like a statement not a joke.

apology accepted.

Oh what a clever little boy you are ... such a witty reply.

How old are you 15 ?

Anyway. Enough forum heroics.

Anyone else noticed an audible sound quality drop when using a ground loop isolator?

laptops aren't grounded, and the AC brick has a plastic case, i really don't see the functionality of a ground in this case. Regardless of if you have a ground or not, the breaker is going to trip, the point of grounding the case is.. that if for some reason (internally) an electrical contact touches the case, it wont shock you when you touch it, the grounded case will trip the breaker. Regardless of a ground or not, a short circuit will trip the breaker....

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Originally Posted by Karlos Santos

If removing the Ground Pin stops the Hum, then its playing some part in the equation then isnt it.

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I guess this more or less finishes the discussion whether or not the laptop ground is used, at all. As soon as I disconnect the power supply and let the notebook run of its battery the noises stop.

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Originally Posted by Karlos Santos

Dude how can that be called "alright". Any good Club owner would fire your ass out the building if you short his fuse box out cus you snapped the ground pin off.

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Exactly. That is why I was asking a lot of people and also opened this thread. I just wanted to be sure that it wasn't my fault.

Again just out of interest, does anyone know how those ground loop isolators work?

some more insight: http://www.physicsforums.com/showthread.php?t=201439