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Posted by Dj Ve on May-20-2004 12:47:

Grounding problem?

Yesterday I mixed for some hours, and started to notice a humming-noise when I came close to the needle on my right deck. I thought " weird " and continued. Thing is, now I`m wondering what the hell this noise is. I`ve double, probably tripple-checked the grounding cable. It`s never been yanked ... ever, so I just can`t figure out why the hell something would be wrong with it now. My setup is currently Pioneer djm600 and dual Technics 1210 M3D with ortofon concord silvers. One theory is that something is loose in right player, probably the groundingcable, but it doesn`t feel loose at all. I`m just praying to the good lord that my mixer isn`t going bust. Can`t afford to have it fixed

PLEASE help .. if you have anything smart to say. Even stupid shit is welcome, because I really want to fix this...

Posted by Dj Ve on May-20-2004 14:42:

it seems this " buzzing " sound has something to do with the headphones volume. When I turn the volume on the phones volume knob all the way down, the buzzing goes away. What is still strange is that if I`ve got deck 2 cued with sound on the phones, try to put my hand near the needle it will start to buzz. If I then put the back of my hand down on the turntable while holding the needle, the buzzing will go away. It seems there is some correlation between the grounding issue and the headphones sound issue .. just can`t figure out what the hell this is. I`ve tried about every cable-swap there is ...

Posted by tu_face on May-20-2004 15:15:

have you tried switching the cart? something may have fucked inside it..?

Posted by Dj Ve on May-20-2004 18:05:

tried changing the needles with .. erm .. everything. The whole thing. So .. uhm .. they don`t seem to be the trouble. But they COULD be equally worn out
Could this be a result of worn-out needles???

Posted by DJTJ on May-20-2004 19:48:

Hmmm..... interesting.

Take the headphones out of the socket. Does the buzzing go away? Turn the headphone volume up and down without the headphones in. See what happens.

Try a different set of headphones. If you only have a set of walkman-style earphones it should still be OK as long as you have a 1/8" -> 1/4" converter. If the problem goes away with different headphones then its obviously a problem with the headphones.

If the problem persists with no headphones in the socket, then it sounds like it might be a mixer problem. If you can possibly get hold of another mixer to test it with, then do so. Try to keep everything else the same and just swap the mixer - use the same cables, headphones, needles etc.

Basically you need to try and eliminate everything. Change one thing and one thing only at a time - if you change two things you cannot be sure which it was that made the difference.

Hope this helps.

Posted by Dj Ve on May-20-2004 20:11:

I`ve tried with different headphones. And the problem does not occur out of my speakers, this seems just to be a heaphone problem. Could the headphones do a kind of groundloop? I`ve heard about the groundloop. I have actually when I think of it, changed the golden plug which I plug my headphones into ... could that possibly be the case?

Posted by DJTJ on May-20-2004 20:19:

It's not likely to be the plug.

I guess its possible that the headphones could be involved in some kind of feedback loop.... how loud do you have your headphones? If you have them quite loud and you put them close to the needle, then it could be that the sound waves coming from the headphones are causing the needle to vibrate more, which causes more soundwaves in the headphones, which causes the needle to vibrate more and so on ad infinitum.

The other possibility - and I can't be sure about this, I haven't done electronics for a long time - is that the headphones could be causing an induction loop, or there may even be a short somewhere. I can't be sure.

It happens with different headphones you say? Definitely its something to do with the mixer (I would say). Try swapping the mixer, borrow a friend's, anything. See if you get it with another mixer. If its just your mixer it happens with, I think its possible there could be a short in there somewhere, or the headphone output is bleeding into the TT input, or something like that. If its a new mixer you should be able to get it sorted under warranty. If not, you might have to get some electronics bod to have a look at it for you......

Posted by Dj Ve on May-20-2004 20:22:

hmm .. suppose it could be the mixer. But the really strange part is that when I act as grounding MYSELF, the sound disapears. Same thing happens when I have the phones level to 0 ... If it is my mixer, I`m in deep shit. Only looking at it would probably cost me aprox 100 usd ... so .. hope it is the phones or something...

about the volume. I have been having the volume pretty high up before. The strange thing is probably that this started after I changed plug in the phones input. Hopefully, without understanding it, I really hope this is the issue. Will try the original plug tomorrow when I get hold of it again.

Posted by Dj Ve on May-21-2004 19:57:

Problem solved. Turns out my fancy-schmancy designer-lamp standing about 0.5 meters away from turntables and mixer caused a disturbance in grounding or something like that. When the person I live with suggested I turned off the lamp, everything was dandy. So boys and girls, NEVER have a big shiny god damn lamp next to yer precious bits and pieces ( and by that I mean decks and mixer. ) Problem solved. OWEEEE