What could cause weird mixer noise.... dirty power?

[TedEH]

So I've been having weird things happen to my little mixer I keep on my work desk - in particular, at random times I would hear what sounds like popping electrical noises coming from my monitors. I had a panic the first time thing happened 'cause I thought maybe my monitors were failing (and they aren't that old - less than a year). Most of the time I wasn't right in front of it when it happened. When I finally saw it happen, I noticed the level meter on my mixer maxed out while this happened.

There's two things that are sort of.... "interesting"...about this. One is that I've previously been noticing one of my monitors (as in screens) would occasionally shut off for a couple of seconds and come back on. I thought it was a driver thing, or a bad cable or something. I didn't think much of it. But the second thing I noticed is that today I heard the tiniest crackle noise, and I thought the mixer was going to act up again, but a lamp nearby started flickering and then burnt out. All of this stuff is on the same circuit. This left me wondering if it's possible that the lamp was dying, and this was somehow dirtying up the power in a way the mixer couldn't handle. Is that possible? Does that kind of thing happen? The light burning out wasn't long ago, so I'll keep watching, but who knows. Curious if anyone might have some insight.

The setup is basically:
- Yamaha MG10XU -> Adam T7V. The monitors are hooked up in the monitor outs instead of the main outs so that I can use a mic for work calls without feedback.
- I have one mic (Rode m5) plugged in currently, a video game console (through the rca jacks), and PC audio coming from USB.
- There's a fair amount of stuff that I assume is all on the same circuit -> guitar amp, couple o lamps, work PC, monitors (screens and speakers), an old PS2, etc.

Am I just talking nonsense? Maybe the mixer is just dying.

 

[NazVonGates]

Might be a power surge in your place if you seen the screens flicker like that. I used to live in a small bachelor apartment recently and I noticed the fridge been on, or a fan on in the "living room," was making my mic pick up interference noise in the higher freq. I came to the conclusion that my whole apartment was wired on the same circuit. And no money would fix it other than getting an electrician in there to look at it. I was ready to buy power conditioners, ebtech hum x plugins. A worker at a PC shop recommended I power my computers with a UPS power backup. Cause I brought it up with him too that my mixer was picking up interference in recordings.

So in short start with the source. Your power. I was looking at videos like this when I was dealing with the same problem of high pitch hums, dial up sounds and that.

I moved from that small place fortunately. Cant believe I had to raise my son in there for the first 6 months of his life. Got into a brand new apartment, switched to a yamaha mg12xu like your mixer and have had 0 noise other than the room noise now. I still use noise isolators at the end of each connection just for safe keeping and it helps. https://amzn.to/3DnxlNQ they also have noise isolators for monitors. https://amzn.to/3wJbO0A and RCA cables. Im assuming your consoles still use these connections. https://amzn.to/3qIOKLF

 

[tedtan]

Could be bad power, but that is usually more buzz/hum. When I hear pops or clicks I tend to think of heat, like some component about to burn up or similar.

Can you track the noise down to a single channel on the mixer?

 

[Turd Ferguson]

Not sure if this will help or not. A while back I posted a thread about a real old Alamo amp I have. When I first had that amp overhauled and got it back, the pilot lamp flickered. The amp also sounded weird when it was flickering - like static. I took the bulb out and cleaned the contacts. It stopped flickering, and the static went away.

So I think that kind of thing can happen...in one device. Not sure it applies to multiple devices on the same power circuit though.

Maybe try powering your mixer from a good quality power strip with filtering (if it's not already) and see what happens.

 

[TedEH]

So I had a theory that maybe I had a driver problem and something in Windows was making the mixer go wonky - and I'd noticed I hadn't updated in a while, as well as I didn't seem to have the ASIO control panel dealy that would indicate I'm using the proper drivers. So I did the install and..... things seemed good for a while! But then yesterday it happened again, and the noise lasted long enough for me to twiddle some knobs while it happened.

To describe it - basically, suddenly, the mixer would light up - the meter lights would all light right up including the peak light - and it makes this horrible popping/peaking noise that keeps going for several seconds. During this time, I can turn every knob on the mixer down, and it continues to happen until it seems to just decide it's done having a tantrum. And it only seems to happen when it's been on for a while..... which leads me to believe maybe a component is failing, or some dust has gotten into it, or who knows what.

I'm temporarily going to switch to an old tascam interface I've got, which unfortunately will be kinda funky to deal with since it's not a mixer, but it'll keep me going until I figure out what happened, and without the risk of doing something funky to my monitors with the noise. Also if it happens again while using a different interface, I can rule out that the mixer is the source of the problem (but I kinda doubt it).

And because we're the types to use any excuse to look at new gear - it has me poking around for other little desktop mixers with usb functionality. Kinda liking the ZEDi-10 at the moment because it would potentially solve some routing problems that the MG mixer doesn't handle well (in particular, being able to have per-channel control of what goes to monitors vs. main outs, which the MG doesn't really do at all).

 

[NazVonGates]

To describe it - basically, suddenly, the mixer would light up - the meter lights would all light right up including the peak light - and it makes this horrible popping/peaking noise that keeps going for several seconds.

My mackie VLZ204 had the same issue. I had to make sure the track I was using wasn't looping into itself.

I used it for 2 pc, monitor(pc screen not speaker monitors), my microphone and outboard gear. Then I tried to output the master bus with a 3.5 back into my streaming pc.

My way around this was to add a interface and have the master xlr output going into the interface, carefully match the gain levels and that was my way around it. Even with my mg12xu I still use a interface to go into ableton live, then send it to my mixer channels 1 and 2, hard left and right. Gain match, then its off to my streaming pc for streaming if I want. No added latency.

 

[TedEH]

I had to make sure the track I was using wasn't looping into itself.

I'm not talking about a routing or feedback issue. This will still happen when the mixer has nothing plugged into it, and all the channels + master are shut off. Also, this is a configuration I've been using without issue for over 2 years.

 

[NazVonGates]

Ok I still think its a ground loop issue and it probably damaged your mixer over the years. It might affect everything else the same way eventually.

 

[TedEH]

What you just described isn't a ground loop. I'm confident at this point that the problem is neither a ground loop nor a feedback loop.

If you're suggesting that there's some kind of subtle feedback loop that somehow went undetected and slowly destroyed the mixer over time - I don't believe that's how any of this works.

 

[TedEH]

Something that IS interesting is that I managed to catch a really short video of it doing the thing - and I noticed something I hadn't spotted before:
The channel 4 peak light is ALSO lit up. I never use channel 4. It had nothing connected and the volume+gain were both off. Maybe some dust got in and/or that channel is shorting itself somehow.

 

[tedtan]

Yeah, a little Deoxit wouldn’t hurt.

 

[TedEH]

It wouldn't be the first time taking something apart, cleaning it, and putting it back together fixed it. Worth a shot. It has admittedly gotten pretty grimy.

 

[Soporific]

I didn't think it was possible, but I had a Display Port cable that introduced random noise. Moving the cable helped but ultimately I just used an HDMI cable instead.

 

[jack_cat]

This kind of electronic gremlin requires (IMO) testing every possible component by swapping it out with another one known to work. This would include the mixer itself and all cables etc etc. Borrow equipment from a friend if necessary if you don't have duplicates.

Two anecdotes: (1) I got a new preamp, the spring in the input jack was nice and strong, and the spring in the input jack of the old preamp was flabby. My guitar cable was broken at the jack: the little plastic ring separating tip and sleeve had broken, but it didn't short in the old preamp and it did in the new.
Took me a while to figure it out, because the cable worked in the other preamp! Exact same problem with a friend with a new amp: the broken cable worked fine in the old amp, but what's this buzz?

(2) I had a Zoom H2 recorder plugged into the aux outlets of a Soundcraft mixer. Leaving aside the issue of incompatibility between +4 & -10 DB, it turned out that powering the H2 from the handy USB power port on the mixer was causing noise; when I powered it from the wall, that particular problem went away. The noise in that case was a weird random popping.

I have a little two-mic Yamaha MG mixer and love it, it is hard to imagine it failing, but the channel four clip light coming on on yours is likely the culprit, isn't it? I hope you have a competent electronics repairman to open it up and look at it for you. Somebody I know said that those dual function inputs on that mixer that take both XLR and plug (If it's like mine, not shown in your photo) are easily broken, although I haven't seen this myself. You might try blowing some canned air down the input jack in case there is some bit of debris in there that might be easily pushed aside into the further bowels of the machine where maybe it won't do any more harm.

 

[dspellman]

I've run into this before, but mostly when I'm playing somewhere on a flatbed trailer with a big diesel generator providing power.

Sometime back I picked up one of those big server-class UPS units with a seriously large lead-acid battery tucked inside (actually, it's a pair of them).
There are a number of different KINDS of UPS. This one charges the battery from the house power. It simultaneously provides clean power, rectified, from the battery. In short, the power to its outlets is absolutely clean, no matter what the input power may be. Needless to say, it intercepts any power glitches long before they get to your gear. Also needless to say, if the power drops below a certain level, your gear keeps working (no brown-out symptoms) optimally. We've had generators cut out completely, and it's a little bit embarrassing that my gear keeps on running and making the proper noises while everyone else has been kicked offline.

 

[NazVonGates]

I've run into this before, but mostly when I'm playing somewhere on a flatbed trailer with a big diesel generator providing power.

Sometime back I picked up one of those big server-class UPS units with a seriously large lead-acid battery tucked inside (actually, it's a pair of them).
There are a number of different KINDS of UPS. This one charges the battery from the house power. It simultaneously provides clean power, rectified, from the battery. In short, the power to its outlets is absolutely clean, no matter what the input power may be. Needless to say, it intercepts any power glitches long before they get to your gear. Also needless to say, if the power drops below a certain level, your gear keeps working (no brown-out symptoms) optimally. We've had generators cut out completely, and it's a little bit embarrassing that my gear keeps on running and making the proper noises while everyone else has been kicked offline.

If I stayed in my old apartment, built in the 60s, I would have went with this route eventually. Or complain about it and get an electrician to ground my outlets in my "studio" room. I still think there's power surges in his place and it damaged his mixer over time. *he notices lights flickering, his computer screens flicker, the channel that lit up and peaked for no reason all suggests, to me anyway, that there's faulty wiring somewhere. Starting to overload one single fuse. I feared this before and got a furman power bar that protects against emi, rfi, and surges. The cable was so long I plugged my pc's into it and stretched the cable out to another room. I still heard interference this way. The fridge turning on caused a ground loop issue, and a fan turned on in the other room caused my RE20 mic to pick up a high freq cycle.

 

[TedEH]

So I did the teardown+cleanup+reassemble, aaaaand it didn't work. The mixer still generally works, but I have a suspicion that there's a fault in the 48v switch. When it does the noise thing, all the channels that support 48v light up. Either something about the 48v is broken, or the cable has died and is dumping that 48v where it doesn't belong, or maybe the mic is doing that. I could have sworn it happens without the mic or cable plugged in though. I'm leaning more and more towards the board just being dead. I've been temporarily using the same mic+cable in a backup interface, so I have doubts that it's those.

 

[TedEH]

And no, I'm not convinced that I have faulty wiring in my apartment - I kinda regret bringing that up since everyone seems to have latched onto it, and it's the least likely culprit. All of the other "symptoms" are easily explainable by other circumstances. The lamp in particular was an ancient bulb that burnt - they do that - and has been fine since I changed it.

 

[dspellman]

If I stayed in my old apartment, built in the 60s, I would have went with this route eventually. Or complain about it and get an electrician to ground my outlets in my "studio" room. I still think there's power surges in his place and it damaged his mixer over time. *he notices lights flickering, his computer screens flicker, the channel that lit up and peaked for no reason all suggests, to me anyway, that there's faulty wiring somewhere. Starting to overload one single fuse. I feared this before and got a furman power bar that protects against emi, rfi, and surges. The cable was so long I plugged my pc's into it and stretched the cable out to another room. I still heard interference this way. The fridge turning on caused a ground loop issue, and a fan turned on in the other room caused my RE20 mic to pick up a high freq cycle.

Or ghosts. Who ya gonna call?

I've played on bar stages behind the bar that had a wall of neon signs on one side and a dying ice machine plugged into the same circuit the band used. Good thing it was a noisy bar and that the patrons were half blind most of the time anyway. They were convinced we were awesome.

 

[TedEH]

For the record - I tried the mixer again - left it sitting, on a different circuit, nothing plugged in, all the knobs and switches off and.... it still happens. The board just spontaneously lights up like a xmas tree every hour or so.

I've stuck my old Tascam us1641 in it's place for now because I need something to work with - and while I lament the missing mixer features, it'll do the job for now.