I usually post my videos in the ‘Controllers and gear reviews’ section of the forum, but as this is more a general tip for digital DJs I thought I’d post here instead.
(I won’t be offended if you move it, mods)
Basically, I’ve had issues with ground loops at some venues ever since I started using computer hardware for gigs.
So the video talks about what they are, in general terms, and some ways to combat them.
Just to add (for our UK friends) some of the cheaper Ground Loop Isolators are pretty useless especially those sold at CPC.
From experience, if you wanna keep cost down (not buying the ART) then I suggest the Shark Isolator that you can get from Maplins. I know Maplins can be overpriced but the Shark Isolator works for me at one of my venues where the ground hum is particularly bad especially (as you say) when I have a slide show playing out of the Mac to a projector via Thunderbolt/VGA.
Having read your replies, I’ll probably update the video description to make it clear they’re often found in car technology stores. That info could be lifesaving if someone discovers a massive loud ground loop in the evening when soundchecking before a gig!
I have one that is made by a company called ‘Carpower’ and was for use in cars and it is completely useless
One to avoid for sure.
This is very handy thread. It would be good if people could post up their ‘Good’ and ‘Bad’ experiences and which products work or not in their country.
Great video! I often recommend another solution for ground loops - the EbTech HumX. I’m not personally a fan of using an isolation transformer to address ground loops, because they negatively effect audio quality. The HumX works in the power path and maintains ground, and it can even be used with a power strip to protect several items at once.
I’m not sure if they make anything other than the US model, though. You could always adapt both ends, but that’s bulky and a pain in the ass. But it’s a fantastic product I’ve used for years.
That’s an interesting unit. Despite the bulky adapters it may work well as a fixed unit in the bar that I have a particular ground hum issue. I haven’t seen anything similar in the UK apart from ‘mains conditioners’ but unless I can get one on trial basis I’m hesitant to buy one. Even these are known to have some adverse affect on audio quality but to be honest, a slight deterioration is a whole lot better than the HUUUUUUUUMMMMMM that I get without using any kind of isolator.
The simple way to get rid of mains hum in some bars is to turn the fridges off… trust me, it works. Unfortunately that means my bottled beer will be warm and that’s THE last thing I want
Great Vid Mojaxx, I like watching everything you make cause your not selling anything, just offering advice.
I use a cheap $5 one, it sounds fine, granted I don’t have perfect ears anymore after giving them abuse for too many years, but everything sounds un-colored using it, and I get good contrast from my studio monitors.
Just occurred to me the question: why hasn’t optical spdif made it as a standard to replace rca?
At least for the prosumer market of amps mixing consoles and sound cards…
At least in 2014…
Of course there is some equipment existing featuring digital and optical ins/outs - but it’s not the majority.
The majority of DJ equipment still has no optical spdif whereas almost all consumer home audio nowadays has it.
My point here is not about that its digital, but that the optical interface will also automatically guarantee that the connection is galvanic isolated - thus 100% hum free.
I must admit - I’ve always avoided ground loop issues by altering my set-up. But - it seems to me there are TWO ways to resolve a GL issue:
Intervention at the POWER outlet
Intervention in the AUDIO signal chain
My question is - how do you know if you should intervene at the POWER source, or in the AUDIO SIGNAL CHAIN???
Does it matter where you intervene? Are there different types of hum/buzz?
I have tried one of the cheap car audio GL eliminators (looked exactly like the one Karlos linked to), I think it was about £4. It did absolutely nothing.
If the device is double insulated it won’t have an earth, IE CDJs 2 core figure of 8 cable with a plastic earth prong on the plug simply to open the live & neutral openings on a socket. New CDJs and Pio mixers (From 800 above? not seen a 750) use a 2 core IEC lead which also has a plastic earth for the previous stated reason
Yeah the cheap ass one simply don’t work. The Carpower one I have was about £5 and is useless. The Shark isolator is far bigger and was £14 and works in a bar that has horrendous Ground loop hum.
They all “look” the same but they don’t all work the same.
