This is a very strange one so please bear with me. I have a hard wired Shure SM58 in Mic 2 with a 1/4 inch jack. Never been a problem. Lately I noticed a buzz, almost like a ground loop or something. I noticed if I stood back a bit, it would go away, so it seemed that proximity to the powered QSC K12 was an issue. No big deal. Next week it happened again but moving back didn't help. I tried new mic cables, no help. Tried a new mic, that didn't work.
On Mic 1 I have a wireless mic receiver so I tried that in mic 2. Sounds find. Also tried it with the cable that was buzzing. Sounds fine. So the cable is ok.
Then I plugged the buzzing cable into my wireless receiver in the Mic 2 jack. Sounds fine. So both Mic inputs on the mixer are fine.
Yesterday I ran a separate wireless mic receiver into Mic 1, with the symptomatic cable. Sounded perfect. Then when I plugged in my Shure 58, it buzzed again. I've tried 3 different mic's and they all buzz -- 2 of them were brand new. Last night if I physically touched the mixer, the buzz went away. As soon as I let go, it came back.
I unplugged my main power source and put a 3 to 2 adapter on there, removing the ground. That made it worse.
I've tried to troubleshoot as best as I can but I am baffled. Both mic inputs work with wireless receivers and both mic inputs buzz when I plug a hard wired mic into it. Remember it sounds fine even the the cable that's buzzing, when I use wireless receivers. So the cable is fine. If it's the mic, why are all 3 mic's giving me an issue?
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I have to applaud your troubleshooting - you've taken all the steps I would recommend to eliminate the potential problems.
Unfortunately it sounds to me like the mic pre-amp is acting up and the SX will require servicing. Your best bet would be to contact Pioneer technical support to arrange to have the controller inspected.
ok thanks for the feedback. this is good to know. i plan on contacting tech support as you suggested. but before i actually ship the unit back, can you tell me if its the same mic pre-amp on both mic 1 and mic 2? if so that would make sense. since it buzzes when plugging a hard wired mic into either of them. and based upon this logic, since the wireless mic receivers sound great, do i understand correctly that the pre-amp is uninvolved when using wireless receivers? thanks again for the quick reply
Each channel would have its own pre-amp. The buzzing could be due to an internal short, but I'm no expert on those technical electrical issues!
The mic pre is only used when connecting mic-level devices. If you have your wireless receivers set to output a line level signal, you should not connect them via a mic input. I presume, as you have connected them to the mic inputs, that the output signal level is set to mic.
Can you please watch this YouTube video that I made last night? I was going to ship my unit in for repair as you suggested, but before doing so, I wanted to test this issue with my friend who has the same exact unit. Upon doing a side-by-side test with each unit I found that his DDJSX has the same exact symptoms. I tried in his office then tried in my office. Both units buzz when plugging in a hard wired mic into either Mic 1 or 2. The buzz goes away if I touch the top of the mixer. Both mic channels operate fine when using a wireless receiver. I've tried different hard wired mics and I've tried different mic cables, different speaker cables, a different speaker. And Ive tried different outlets, and 4 different venues. Completely stumped here. You had initially said that it sounds like my preamp is acting up, but if that was the case, doesn't it seem exceptionally strange that the same exact problem is occurring on another unit that has barely been used? If you watch this video you can clearly hear the buzz come and go as I touch the top of the mixer. Thanks again for your help, hope to hear from you soon.
https://youtu.be/_vS0LlQeguU
The original production run of the SX had an issue with the mic preamp where it would distort with certain microphones, but this doesn't seem to be the case as it was only when the mic was used - not when it was idle. I have the same setup (SX + SM58 mic + QSC K10's) and I certainly don't have that buzzing.
I'm going to assume that this also occurs when you have a computer connected via USB?
Yes it occurs with computer connected via USB. But when I recorded that video last night everything was unplugged except the mic, in order to eliminate variables. I think it might not be the best idea to ship the unit back since its symptomatic on 2 identical units. Plus I really need it to perform every weekend. Any suggestions at this point? Thanks so much
I've passed this up to the engineers to see if they have any suggestions before recommending servicing.
ok thank you. i will wait for your feedback before sending the unit in for service. please keep me posted. much appreciated
just wanted to share a few more videos that i filmed at setup tonight at my gig.
this video shows 2 different SM58s buzzing on unit #1, which has barely been used. maybe 6 gigs. please read the video description that i wrote for more info.
https://www.youtube.com/watch?v=yPydQKrvlYg
this 2nd video demonstrates the same buzz with a hard wired SM58 on a different DDJSX with a different mic cable, then when i plus in a wireless mic receiver, the buzz goes away using the same cable. whenever there is a buzz, if i physically touch the deck plate, the buzz goes away almost entirely. the last video i shared was in my studio. this video is at my venue at tonight's gig. again sorry for the brief feedback, i was really sloppy trying to film and demonstrate with only one hand free, but you'll get the idea.
https://www.youtube.com/watch?v=fP8fXGRkeKg
can you advise me as to what engineering said? it's been since april 24th and i haven't heard back yet. i also sent 2 more videos showing the issue in action. please let me know what we should do. thanks again
Sorry @greg, the engineers were all off work last week for Japan's Golden Week. I'll hopefully get some info for you this week. Thanks for your patience.
@Greg > I see from one of the videos you're using an XLR cable - it's possible that there is an issue with the "cold' pin on the Mic 1 input. Have you tried it with an unbalanced (TS) cable and not a balanced (TRS) cable on inputs 1 and 2?
i have tried it with a TS cable on both mic 1 and mic 2 inputs on the mixer. same problem. That's what i normally have plugged in mic 1 anyways. i bought a new TS cable and tried that. same problem on both mic 1 and mic 2 inputs. that's when i bought a new XLR cable and tried that. same issue on both mic 1 and mic 2 inputs. then i tried another XLR cable. same problem on mic 1 and mic 2 inputs.
all of these cables were also tried on the other SX unit that i had side by side and the symptoms were identical
i also bought a new mic and tried that with all these cables. still had the same issue
but if i plug any of these cables into the back of QSC K12 speaker or K10 speaker, there is no buzz and i can use all my mic's and all my cables with no problem
I figured you had likely tried all that but the engineers are asking so I wanted to make sure.
Thanks again for your patience while we try and sort this out.
