Earthing noise

lauke-lux

lauke-lux

Fractal Fanatic
Encountering a weird problem, since a few months probably, but yesterday as I was parametering my patches on live level without band it became quite insupportable.

Whenever I play open notes ie with no left hand on the string I get low crackling noises at each string I touch. It came on suddenly a few months ago but at low level it didn't really bother me.

Whatever is the guitar or cable I use it remains. BTW I also use ground lift since that time as with ground lift off there's a hell of a noise coming out of my XLR cables (that are wired XLR (FM3)-Jack(PA))

Will send some audio samples and patch examples tonight; my fear is that something might be wrong with the input circuit as I can't seem to resolve it changing cables, guitar, gate settings or geographical use (wether I use the FM3 at home or elsewhere).
 
Make sure all the electrical equipment connected to the modeler is on the same circuit in the room. If you had to use the ground-lift that’s a pretty good indication they’re not, and you have a ground loop. If you’re not sure, the simple way to protect against that is to plug everything into the same power strip, or a second power strip plugged into the first one.

Is the connection from the FM3 to PA using XLR connectors at both ends, or is one end using 1/4” TS plugs?

If you disconnect the FM3 from the PA, and plug in a pair of headphones, is the sound less noisy or the same? Does the noise go away if you disconnect the guitar cord from the FM3?

We don’t know enough about your setup, so describe it in more detail.
 
Back home. At home all is connected to one single 9 outlets power strip like yesterday (4 outlets prolongation cable, but yesterday connected to a non earthed wall outlet. I'm using as described two XLR - 1/4" TS plus cables that have worked flawless with my former Axe Fx II for years.
  • Connected to small PA with XLR-XLR no change. Earthing is correct at home (maybe the unearthed wall outlet of yesterday explains the difference with the ground lift ? althoug factually everything was ground lifted yesterday)
  • BTW at home "ground lift" doesn't alter anything, and yesterday was not over PA but over a MF10 active speaker (the pre G66 model).
  • Changed the guitar cable, but it does this with any guitar (one guitar can have a problem but not all)
  • Disconnected the input 1 EXP pedal and input 2 hotone switch : no change, same problem
  • Headphones : no change, same problem
  • I'm at home, alone, no frequency converters running for heating pumps, laundry or whatsoever
  • I have to go out shortly with the dog before he explodes but will connect my FM3 later tonight to a computer and do some recording over USB and also do a recording just with a mic while playing over my small PA. This only is audible when I have nothing touching the strings (left hand taken off and just playing open strings with my right hand without anyother body part touching the metal parts of the guitars)
  • My setup is here https://forum.fractalaudio.com/threads/lets-see-those-fm3-rigs.158779/post-2038944

The Axe Fx II mark I that I sold lately did not have this behaviour . With no guitar cord connected there is no noise. As a matter of fact, I more and more believe it's not an output issue but an input circuit issue.
 
I put it here on a soundcloud account I have .
The mp3 format fllters a bit of the noise and the soundcloud compression filters it out even more. But on the second patch in the last seconds of the recording you can notice quite well. Here I play at low level but if I put up the volume it's even more audible not to talk about a little bit more distorted patches.

Tomorrow I'll be out and be back late but I might try a total reset of the unit. My beforelatest recordings are from June and end August and it clearly is not there on those recordings.
 
lauke-lux said:
I put it here on a soundcloud account I have .
The mp3 format fllters a bit of the noise and the soundcloud compression filters it out even more. But on the second patch in the last seconds of the recording you can notice quite well. Here I play at low level but if I put up the volume it's even more audible not to talk about a little bit more distorted patches.

Tomorrow I'll be out and be back late but I might try a total reset of the unit. My beforelatest recordings are from June and end August and it clearly is not there on those recordings.
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It looks like the problem is internal to the FM3 since it follows the FM3 to different buildings and swapping guitars and cables didn't fix it. I'd contact Fractal's support. There's only so much to try when dealing with hum and electrical power, and it's not worth being frustrated or continuing to try to find a work-around.
 
Greg Ferguson said:
It looks like the problem is internal to the FM3 since it follows the FM3 to different buildings and swapping guitars and cables didn't fix it. I'd contact Fractal's support. There's only so much to try when dealing with hum and electrical power, and it's not worth being frustrated or continuing to try to find a work-around.
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Yes, totally agree, I'll do a backup and a global factory & system reset before calling on G66. I do need the unit until nov 8th but can leave it then for a week after. Generally G66 are very fast. It is audible most while playing slow things as you have to take your hand off the neck for moving up/down the neck without too much string noise.
 
lauke-lux said:
Yes, totally agree, I'll do a backup and a global factory & system reset before calling on G66. I do need the unit until nov 8th but can leave it then for a week after. Generally G66 are very fast. It is audible most while playing slow things as you have to take your hand off the neck for moving up/down the neck without too much string noise.
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I’ve heard that sound before, and I’m pretty sure it’s due to bad grounding, or grounding issues, but I’m not an expert. And, given that people have died because of bad wiring, I’d rather see you get it checked by those who do know. Better to be safe than sorry.
 
Greg Ferguson said:
And, given that people have died because of bad wiring, I’d rather see you get it checked by those who do know. Better to be safe than sorry.
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I was almost one of them at a Hallowe'en house party gig in Trenton 33 years ago. It took a pint of tequila sunrise to stop my hands from shaking....

Do please get the wiring looked at and verified safe!
 
Not to boast around, nobody is perfect, but as a confirmed electrical engineer : there is no grounding issue at home. And no 3 Phase power connection that could eventually be at risk with uninsulated connections.

I'll give it a chance with a total reset of the unit before escalating with after sales. On my fx2 I once had a 3dB difference on L/R out1. Sent the unit to G66 who indicated that a total reset cleared that; who knows why. If nothing comes out of this total clearance-> G66 will check and eventually correct. Feels a bit like these old Bob Dylan lyrics; "Something is going on but you don't know what it is, ...do you Mr Jones?"
 
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