ground loop interference

[kaini]

for about a year i have had a mental problem, where teh sound from winamp used to glitch in an almost bufferoverride stylee when i used the scroll wheel on my mouse

 

i always figured that it was the fact my pc is shit and overloaded (even though it didn't appear to be in taskman) - so i engaged in the usual troubleshooting, msconfig, different browser, different media player (quite glad i switched to foobar) - but couldn't crack the bitch

 

tonight i had to disassemble my kit cos i was painting, and when i plugged everything back in, the plug configuration was a bit different for the sake of neatness

 

the scrollwheel glitch problem is now gone

 

fucking bizarre. i work in tech support, and this is a new one on me.

[Guest hahathhat]

i don't think it was a ground loop, more likely radio interference between the mouse cable and an audio one

 

ground loops are a 60hz bzzzzzzzzzzzz too, not buffer override-style glitch.

[qnio]

electronic music

[kaini]

yeah, but the electronic music used to wear a bit thin when reading a long article and listening to eno or stars of the lid or whatevs

 

anyway, bizarre problem

[Guest hahathhat]

also could very well be internal interference - like from inside the case.

[Guest hahathhat]

crazier id: some bus, pci, northbridge junction is really loaded up. mouse fires off a torrent of interrupts, stealing enough attention from the audio that quality suffers.

 

solution, independent of cause: junk the shitbucket man, if it sucks don't use it

[Guest iep]

its interference on one of the interrupt lines, firing off spurious interrupts.. sjust electrical coupling noise, only thing you can do is move your soundcard as far away from the cpu/alu as possible, or magnetically shield you soundcard. i wouldnt worry about it

[Guest hahathhat]

i always heard the deal about keeping the soundcard as far away from other cards as you can... and just 'cos it's no real hassle, i usually try to do that. sometimes, it means moving a bunch of cards, so i skip it. never had any problems.

 

i have gotten audio skippage from when usb on my shit older box got overloaded, audio would do weird (and annoying) things. interface was a tascam us-428, which has always been ghetto, but having it going through a USB 2.0 PCI card really didn't help the situation. i used ps/2, but i wager if i'd put the mouse on that USB card, i would have gotten some aural results.

[sheatheman]

*bumps decade-old thread*
 
this guy talks about the computer processor sound bleed thru phenomenon and says it's also due to not being grounded. if you ever hook a computer up to a guitar amp and drag a window, you will most likely hear the sound. just like a car accelerator being audible in the sound system.
 
for anyone that doesn't know (i just now know), a ground loop happens when two outlets are going to the same breaker, and both are struggling for ground. since they don't have the exact same voltage, that voltage difference comes thru your speakers as a 60hz hum, but variances in voltage (such as a computer working), will also come through.
 
great video on ground loops:

https://www.youtube.com/watch?v=l4famaQmWnA

 
it seems like a dumb thing to be preoccupied with, but when you are working on making a good, modest studio setup, and want to use effect pedals as sends in ableton, chances are you will hear ground loops, especially if the pedal is unbalanced (which most are). sometimes the output going back into the soundcard is really quiet, so you have to crank  it, and that's when the hum will come in REALLY strong, impossible to ignore. i plugged the pedal i was using into the same surge protector as everything else, and unplugged anything that wouldn't fit. that completely solved the problem.
 
but that leads to a major question: how do people set up huge studios with multiple effect racks without plugging them all into different outlets? is the only option expensive electrical work and/or buying a ton of these?

[TubularCorporation]

USB grounding is terrible and an endless source of weird noises and ground problems. Outboard USB gear should have some kind of isolation built in, and usually does (but not always, I'm looking at you Arturia Beatstep Pro) but noise from the USB ports getting into the onboard audio i/o on a laptop is almost a given.  I've actually been meaning for a while to sample the sounds that come out of the headphone jack on my laptop whenever I copy files from a USB thumb drive.

[sheatheman]

Those of you who have real studios with rack cabs (I assume there are several here), how do you handle power?

 

Anyone with more than a dozen things to plug in will have to deal with the prospect of multiple power strips.

[Braintree]

Damn, I didn't look at the post date and thought kaini was back.

[TubularCorporation]

Those of you who have real studios with rack cabs (I assume there are several here), how do you handle power?

 

Anyone with more than a dozen things to plug in will have to deal with the prospect of multiple power strips.

 

I've got a medium sized rack in a decidedly non-real studio and I've seen isolation devices like rubber tabs that keep the chassis grounds of each device physically isolated from each other to avoid ground loops but I've never had an issue, the only ground troubles I've had were when using a Beatstep Pro connected to a USB hub or computer, which caused ground loop issues so bad that even connecting CV to other devices would add hum hat was as loud as the audio output.  IT was a known problem and had to do with the lack of any kind of ground isolation in the USB standard and Arturia's failure to implement it in the BSP (they included an external isolation dongle at the last minute to handle it, but that had the side effect of making their editor software not actually recognize the BSP when it was connected, which was part of the reason I ended up selling it).

 

Basically, any well designed audio device made in the last 40 years shouldn't have issues but "well designed" and "all" are of course totally different things.

 

As long as there's only one path to ground you're usually OK.

 

 

DISCLAIMER: I'm pretty ignorant about this stuff myself.

[sheatheman]

Thanks for reply.

 

The path to ground is the issue though, if you have like, 20 devices like I do, you deal with multiple power strips and the issue of daisy chaining comes up.

 

Are you plugged into multiple outlets and not experiencing noteworthy ground loops?

[Watermint]

I'm wondering if something like this might do the job: https://www.amazon.com/APC-C20B-Outlet-Power-Filter/dp/B00NTJ2QQU/ref=sr_1_2?s=electronics&ie=UTF8&qid=1498527521&sr=1-2&keywords=power+filter