Not a Bug Help with FM3 mk2 turbo high pitched sound

1anP said:
Looks like you have actually "engaged the curse" as your forum alias suggests ;)
I think what members on this forum are suggesting is that its not your house wiring transmitting the EMI/RFI to your guitar. The interference is being transmitted from your fridge's motor, electrical/electronic speed control circuit through the air like a radio in transmit mode. Your guitar equipment is acting like the radio receiver and is suffering the resulting RFI. Modern fridges use inverter technology to vary the speed of the compressor motor to provide more or less cooling as required. Inverter circuits can and do cause the kind of interference you are experiencing.
You can test for RFI and perhaps you may know someone who has a spectrum analyser like in the video below?

Click to expand...

Hahaha i picked the alias based off of a preset on NDSP’s Nolly X plugin.

Thank you for the input though. Today I called the electrician again to do some more inspection and had him change the fridge’s line to a different circuit on the DB only to find out that it didn’t matter. It reinforces your point even further that the wiring doesn’t matter.

I just checked and those analysers are pricey! I don’t even know anyone who would have such a device.

I have ordered some ferrite clamps which arrives on Sunday to see if they would work but at this point after going through so much and taking all the input from here, I don’t think that would be of any help. I guess even calling LG(fridge) support would also be pointless based on your description of how modern inverters work. I guess removing the source altogether or changing apartments in the only way to Lift the curse.
 
Modern inverters are in your a/c, fridges, washing machines, etc, are designed not to generate EMI/RFI but sometimes a component may fail and they can then generate this type of interference.

Finding someone to help check with a spectrum analyser may be easier than you think. Contact your local Amateur Radio (HAM) club and have a chat and you may just find someone willing to do it for free.

Lets hope you lift the curse!
 
EngageTheCurse said:
I should have mentioned it in my post but yes, i did all the troubleshooting beforehand and found out-

There’s no noise when just my fm3 and monitors are connected and powered on. It’s only when i connect my guitar the noise returns. When I turn the volume knob all the way down on the guitar, the noise does go away. Maybe the guitar is acting like an antenna of sorts? Or it’s an emi issue?

The problem doesn’t exist in 2 other locations i have tested with the same gear and cables.

And i have tried this several times now to confidently conclude that the refrigerators are causing the problem because once i turn them off, the noise completely disappears.

Correct me if i am wrong but the way forward to narrowing down the issue further seems like conducting a headphones test and see if the problem still persists. But that would require me to buy a pair.
Click to expand...

Thanks - sounds like the issue is almost certainly (atypical) EMI through the guitar. If you haven’t already tried it, my next step would be to try other guitars to rule out wiring issue on the guitar. But if all properly-wired humbuckers are doing it, I suspect the only solution is a new fridge (if that’s the o ly thing triggering the issue).

And for context, I have seen scenarios - especially in recording studios - where a particular appliance is inducing EMI that can’t be avoided other than by shutting off the appliance. For example, I recall one recording session where we couldn’t record guitars when the furniture shop next door was using a particular saw…
 
Rumbletone said:
Thanks - sounds like the issue is almost certainly (atypical) EMI through the guitar. If you haven’t already tried it, my next step would be to try other guitars to rule out wiring issue on the guitar. But if all properly-wired humbuckers are doing it, I suspect the only solution is a new fridge (if that’s the o ly thing triggering the issue).

And for context, I have seen scenarios - especially in recording studios - where a particular appliance is inducing EMI that can’t be avoided other than by shutting off the appliance. For example, I recall one recording session where we couldn’t record guitars when the furniture shop next door was using a particular saw…
Click to expand...
I did check with my other guitar(humbuckers) and the noise was still there.

As you said correctly, turning off both the fridges gets rid of the problem. But it is impossible to get rid of the fridge as it’s a necessity and they are always switched on.

As 1anP pointed out that these appliances are designed in a way to not emit emi/rfi so my next step is to call their support and have a look. Not keeping my hopes up but at this point i have nothing to lose except maybe an hour of my time
 
Have you tried rotating the guitar to see if you can reduce the noise? EMI transfer can be angle dependent. I've played in some rooms where just turning around (putting yourself between the noise source and guitar) or tilting the guitar significantly reduced noise.

If rotation and distance from the source doesn't change the noise loudness then it's either: Super loud EMI directly from the fridge components or the fridge is inducing a ripple in you AC power lines.
 
serpo said:
Have you tried rotating the guitar to see if you can reduce the noise? EMI transfer can be angle dependent. I've played in some rooms where just turning around (putting yourself between the noise source and guitar) or tilting the guitar significantly reduced noise.

If rotation and distance from the source doesn't change the noise loudness then it's either: Super loud EMI directly from the fridge components or the fridge is inducing a ripple in you AC power lines.
Click to expand...
I have indeed and the noise didn’t vary at all. I have tested it in 4 different rooms and the noise is still there.

Would shielding the guitar cavity and the back of pickguard possibly work?
 
Amazon sells a "Faraday fabric" ..... not terribly expensive..... you could try putting some on the wall behind the refrigerators or in the studio.

Shielding the guitar cavity/pickguard might help too.
 
eadex51 said:
Amazon sells a "Faraday fabric" ..... not terribly expensive..... you could try putting some on the wall behind the refrigerators or in the studio.

Shielding the guitar cavity/pickguard might help too.
Click to expand...
Putting them on just behind the wall would help? If the emi is radiating through air then wouldn’t it be able to easily radiate through 3 other sides?
 
In theory, your body should also act as a ground plane so you could get an idea of the effect shielding would have by wearing the guitar without touching the grounding metal (strings, bridge, controls, etc) and facing away from the noise source so you're between the fridge and guitar in whatever room you normally play.

Other things to try:

The shortest 1/4" cable you can comfortably play with. The cable is basically an antenna so more length allows it to accumulate more environmental noise.

Check connections. It could be picking up the noise similar to a radio tuner. Anything loose will behave as a capacitor which, in a am/fm radio tuner, affects what station you're tuned into. Could be a solder joint but the easiest thing to check is the input jack. Clean the contacts and make sure they're pushing against the guitar cable when it's inserted. Had a guitar that I re-shielded to get rid of some noise but the issue was the jack.
 
Consider that your refrigerator is almost certainly "skinned" in metal.

That metal should be acting as an EMI shield already.

Look for the spots where it's not covered by metal... I'm guessing only the back and the bottom.

This is the same reason you want to avoid computer cases with parts of the case being transparent rather than all metal, if you're using it in a studio.

You could try just covering the back with some aluminum foil to see if that helps.

I recently got some HS8 monitors which "chatter" when they are too close to my wi-fi router. Apparently this is a known issue with the HS8 monitors not being well shielded.

When I'm recording, I cover the router with a sheet of foil and the problem goes away.

In my case, it's pretty mild - only really noticable when nothing is playing back.
 
Hi,

maybe not directly helpful for this case, but I get interference from the perimeter wire of my robotic lawnmower! This pulses even if the robot is not active to test perimeter wire integrity. This longwave radio signal is in the kHz range and is picked up up by both humbuckers and single coils in my electric guitars (PRS 513). Nothing else I can do but turn off the whole system when I am playing. Long story short: our airwaves are full of signals even from unexpected sources and humbuckers/single coils are basically little antenna's.
 
Ender699 said:
Hi,

maybe not directly helpful for this case, but I get interference from the perimeter wire of my robotic lawnmower! This pulses even if the robot is not active to test perimeter wire integrity. This longwave radio signal is in the kHz range and is picked up up by both humbuckers and single coils in my electric guitars (PRS 513). Nothing else I can do but turn off the whole system when I am playing. Long story short: our airwaves are full of signals even from unexpected sources and humbuckers/single coils are basically little antenna's.
Click to expand...
Yep - you aren't the only person who has reported that.

In fact, that is how I learned that robot lawn mowers even existed. It was from a post here on the forum :)
 
You must log in or register to reply here.
Back
Top Bottom