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Help me get rid of the buzzing noise, please! :)

Learn To DJ With Digital DJ Tips › Forums › Digital DJ Gear › Help me get rid of the buzzing noise, please! :)

Viewing 5 posts - 1 through 5 (of 5 total)
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  • May 20, 2016 at 8:17 am #2397391
    DJ Vintage
    Moderator

    One thing you failed to mention is your speakers. Brand/model/general type.

    You were talking about leads for power, I am assuming you are using grounded outlets?

    1) Speaker on, volume on speaker on max. Ear to the speaker. Any noise?
    2) CDJ direct to speaker (which way did you connect? RCA to balanced cable?). You tried this and the noise was there but very very faint. If you tried this with all CDJs, there is a fair chance that this is “native noise” in the electronics of the CDJs. If at full speaker volume you have to put your ear to the speaker to hear the noise, it will not get louder when you play music over it. And with our typical volumes being at 90+ dB (being modest here), there is no chance your audience will hear that, so it can be disregarded.
    3) Also hook up the CDJ to USB. More noise?
    4) Mixer attached to speakers, nothing on the mixer. But with faders open (master, channel, gain/trim and crossfader). More noise or not. If more noise, does it make a difference if you (in turn) lower master, crossfader, channel and gain?
    5) Hook up single CDJ to mixer. Same procedure as with 4)
    6) Also hook up the CDJ to USB. More noise?

    At point 3) you should be able to determine if this has to do with USB connectivity or not.

    I have had problems of varying sorts, including noises, hums and crackles using Behringer gear, but that is usually on a per piece of gear basis. Point 4) and 5) will help rule out the mixer standalone and with CDJ that you already checked. Finally 6) will rule out the mixer with regards to USB connected CDJs or not.

    May 21, 2016 at 11:48 pm #2398091
    AKSO
    Participant

    Hi

    Yeah I never mentioned the speakers. Truth be told, I need to get new ones but that’s on the shopping list for now. I currently have an old 5.1 logitech x-530 setup. I connect them with an unbalanced phono cable that goes straight in the mixer. I’ve excluded them as a noise source altogether for two reasons. First, I can hear the buzz in my headphones even when the speakers are not plugged in. And second to answer 1), there isn’t any buzzing when the speakers are turned on, volume all the way up and not plugged in the mixer.

    Also, everything that I am using should be grounded properly as my whole setup including the extension lead was PAT tested a few months ago.

    I ran some additional tests today focusing on the points that you’ve mentioned in your post and found some interesting stuff.

    So, I got my old mixer, which is an analog Numark M2 and started compering setups to see what happened. I connected the mixer straight to the speakers, no CDJs were plugged and found the following. The Numark was completely silent.No matter what I pressed or moved there was no noise. Then I plugged one CDJ – usb straight in the laptop (running on battery) and RCA in the mixer. And the problem came back. A buzz when I link the CDJ (press the usb button), which goes away when I move the pitch fader or unlink (press the usb button again) the CDJ. Then I tried the Behringer mixer I have. Again, only the mixer to the speakers. Now, channel 1 and 2 were completely silent, channel 3 and 4 give a bit of buzz. Considering that everything was turned all the way up, I can live with that. I can also hear the buzz in my headphones and interestingly enough the pitch of the buzz changes slightly when I turn them up and down. I suppose the mixer is not the best but again, I can live with that (for now). Everything else was the same when I plugged the CDJ. I also tried all CDJ with different RCAs and USBs and power leads.

    No buttons/knobs on the mixers affect the buzz. When the CDJ is not in usb mode there is no noise, once they are recognised as sound cards the buzz comes back and is also channel specific. If I turn the fader/gain trim down the noise goes away.

    Am I right to think that the issue comes form the CDJs themselves and this combined with the mixer creates the whole issue. Also I didn’t do that today but historically I’ve notices that when I connect my Maschine to channel 4, it gives a very high in volume buzz. I give this to the cheap sound card that I am using with my Maschine and to record (another thing I need to upgrade). Some hum eliminators are actually helping with that at the moment but I’d like to fix the problem centrally.

    Any other suggestions?

    Cheers

    May 22, 2016 at 10:55 am #2398151
    DJ Vintage
    Moderator

    The noise probably is the result of a combination of laptop, CDJ and the USB connection between them. I remember one gig at someone’s house where we also had a nice 50Hz ground buzz and the only way to get rid of it was to unplug the power supply from the laptop, which is double insulated and doesn’t even have a ground plug.

    We made sure the laptop was fully charged when we started the night and we played a long mix somewhere in the middle from an iPhone to recharge the laptop (disconnected usb, charged, then removed power supply again, reattached usb).

    Never had it again, so never bothered finding the actual cause. But it’s an easy test, just unplug your power cable from the laptop and see what that does.

    May 22, 2016 at 11:11 am #2398171
    AKSO
    Participant

    The laptop was running on battery literally the whole time.

    A friend of mine suggested that one of the units it not grounding probably and the interference travels across through the power leads. I think that it may be the mixer because as I said before I find it unlikely that all 3 CDJs have the same problem. Maybe I’ll pick up a power conditioner and try that out. But I’ve already tried putting a transformer on the mains, which did nothing, so I’m not sure it will help.

    May 22, 2016 at 8:49 pm #2398251
    DJ Vintage
    Moderator

    Could be something as simple as a bad ground track on a circuit board.

    However … you did say that even with another mixer as soon as you plugged a CDJ in to USB the buzz returned. Actually you don’t say you hooked up the CDJ without USB on the other mixer.

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