I've had grounding issues ever since I started DJing with traktor, I got so sick of it i moved to vinyl only. But now i'm back in the fold for a little spin, with no ground hum! Yaay! Symptoms: Can you hear a buzz coming through your speakers when you have your laptop on? Does this extend to hearing your hardrive whirr through your speakers? Is there a noticable noise floor when you switch from any other sound source to your laptop? If so, sounds like ground hum. Solutions: These wont work for everyone, you may have other issues with your laptop or house/venue wiring I cannot even conceive. But here are the easiest and cheapest fixes: Ground Loop Isolators: These are dead cheap, plug it inbetween your master out and your amp, they will reduce but maybe not completely eliminate ground hum. http://www.amazon.co.uk/s/?ie=UTF8&...vptwo=&hvqmt=b&hvdev=c&ref=pd_sl_3swmoz3h0f_b Laptop Chargers: This is my recommended fix. Take a look at your laptop charger brick, does it have 3 pins for the connecting plug cable? If so, theres the issue. You need to remove the ground; the third pin. I do not recommend altering the charger in any way, buy a new one! heres a bunch: https://www.google.co.uk/webhp?sour...pv=2&ie=UTF-8#q=logik+laptop+charger&tbm=shop If you buy a new one, make sure its the correct voltage output and get one with 2 pins only. Its the same plug connector as a pioneer CDJ if youre unsure. This IS safe, all laptops are manufactured for the EU/'murica, most of which go not have grounding pins for their plugs. As such, laptops are internally grounded. this has completely removed all ground hum from my setup. For those that will bleat on about apple products, I couldnt care less. My windows machine cost fuck all, has never failed me and a £30 charger solved my only issue.