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.
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.
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.
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.
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.
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…
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.
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.
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
[quote=“Archies’bald, post:16, topic:10646, username: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.
[/quote]That’s not a problem. Some laptops come with a 2-pin (without ground) power supply regularly, for example the macbook.
Ye, that doesn’t sound reasonable and I’m not going to do anything like that.
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).