Crackling sound no one else can hear

M

mumblecrust

Jul 25, 2020
13
4
2,531
#1
You know how in Sesame Street Big Bird has a friend called the Snuffleupagus that only he ever sees? Well, I've got a problem that's rather similar.

My bass developed an electrical crackling noise, slightly similar to the sound you get when turning a dirty volume control, when I played certain notes. So I took it to a luthier and he replaced the electronics, but a while later I noticed I was again getting the crackling noise, but now on different notes, namely the open G string and, to a lesser extent, the open D string. I took it back and the luthier said that the problem was fret buzz and that was to be expected from an inexpensive bass. But the problem is definitely not fret buzz. The sound is the kind of sound you get with poor electrical contacts, as if the G of the open G string makes some electronic components vibrate.

Eventually I gave up and decided to cut my losses and go to another shop where I wouldn't be talked down to like I was an idiot. But, while I was treated like an adult, the person I spoke at the second shop couldn't reproduce the sound, even though he plugged the bass into an amp and tried it out in front of me, so I could see he was doing what ought to have caused the sound.

So I took the bass home, and the same crackling sound came back. I swapped every other possible source of the noise — cable, audio interface, computer, amp, headphones — but I still was getting the noise.

Today I took the bass back to the same shop and spoke to someone else, but he couldn't reproduce the crackling either. So I went home again, plugged in the bass, and found that there was no crackling … at least for a while. After playing for some time, the crackling came back.

Does anyone have an idea what is going on? Why might this crackling only happen sometimes, but not at other times? Is there a way I can either get rid of the crackling myself, or find out how to be sure to be able to trigger it so that I can make sure that the luthier actually sees the problem?
 
#3
1) Are you 100% certain that the sound is emminating from the instrument? - for example, some hearing conditions (even wax buildup) can create a sensation akin to crackling, and can be frequency / volume dependant.

2) is it possible that the sound is an acoustic artefact, and not an electrical one? : Your left ear is closer to the fretboard when you play, but those sounds aren't necessarily converted to an electrical signal by the pickup - and somebody else playing your instrument may not even trigger those artefacts.
 
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#4
HG1180 said:
Its almost certainly the bass you are playing whilst plugged into your amp. Try some contact cleaner on the pots and reheating all of the solder joints.

Report back with results if it doesnt solve the problem, we’re here to help:thumbsup:.
Click to expand...

It's not the amp because I get the same problem whether I plug the bass into my amp or into an audio interface.
 
#5
When I play with headphones, the crackling comes through the headphones. When I play through the speaker of my amp, the crackling sound comes from the direction of the speaker. It's definitely not my ears that are the problem.
 
#6
Take the bass/amp to another house/outlet to see if it goes away.

Another issue could be static electricity. This generally happens more during winter months, or with lower humidity, but never say never. The static electricity can build up around pickguards and pickups, causing that. The easy fix it to rub a drier sheet with static guard over the pickups and pickguard. It will generally get rid of the build up.

Could be dirty power, cord, but the fact two different techs couldn’t find it points fingers to something in your homesetuo
 
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#7
I seem to be having trouble being understood. It can't be any particular one thing in my home setup because I have substituted every element and I still get the crackling sound. It's not my headphones because I get it through speakers. It's not the electricity supply because I get it when I use my battery-powered headphone practice amp. It's not my amp because I get the same crackling through my headphone amp and my audio interface. It's not my computer because I get the same crackling through my amp and my headphone amp. It's not my cable because I have tried two different cables and I have also used my headphone practice amp, which doesn't need a cable. All that's left is the bass and my body.

If the problem were caused by static, why should the static only make itself audible when I play a G2 or an A1?
 
#9
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#10
Crackling usually comes down to 1 of 3 things:
  • Dirty potentiometers
  • Static electricity
  • Intermittent ground
If the pots were replaced by the previous tech then that should rule out dirty pots.

For static electricity, try gently rubbing a dryer sheet on the body of the instrument and repeat your playing experiments to observe any changes.

For an intermittent ground, there are a few potential culprits. The first is cold solder joints to ground inside the control cavity. But this will usually result in consistent crackling, especially when you adjust the volume pot (it often gets confused for a dirty potentiomenter). The second is a poorly shielded cable. But you have already tried different cables.

So the third culprit may be worth checking: are you using coated strings? The strings are connected to ground by touching the bridge and when you touch the strings you become grounded as well. If you use coated strings the coating can become a barrier between you and ground or between the strings and the bridge. In either case the ground is not mechanically coupled as it should be.

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#11
I would further investigate to possibility of static electricity buildup from the pickguard. I had a similar problem with sizzling, crackling, & random pops on my CIJ Precision. I discovered that if rubbed my fingers on the pickguard between the pickup and volume knob, it would produce the sizzling noise, and the random 'pops' came out when a large enough static buildup on the pickguard would discharge through the pots or jack. I read online about the dryer sheet trick, but I didn't want to deal with having to do that on a regular basis, so I got a 12"x12" self-adhesive copper foil sheet and shielded the entire underside of the pickguard, and that shielding of the pickguard totally solved the problem never to return again. Other than that one issue of my unshielded pickguard building up static electricity, my CIJ Precision has been outstanding in all other respects, it's a higher end model that came with USA pickups, etc.
 
#12
These types of problems are the kind that can drive you crazy. I would try cleaning off the contact on the lug of the output jack (while you're in there) and bending it inwards to improve the angle. If you play the bass with the same cable in the same position (especially sitting down with no downward gravitational pressure on the cable) it is possible that the cable ground isn't making complete contact with jack. When you bring it to a shop, the bass isn't in the same playing position and the contact is stronger due to that. The noise stops. You get home, go back to the normal circumstances and the problem starts back up again. Hopefully it's something simple like this. Try looking at all of the free easy fixes first. Best to you.
 
#13
mumblecrust said:
I seem to be having trouble being understood. It can't be any particular one thing in my home setup because I have substituted every element and I still get the crackling sound. It's not my headphones because I get it through speakers. It's not the electricity supply because I get it when I use my battery-powered headphone practice amp. It's not my amp because I get the same crackling through my headphone amp and my audio interface. It's not my computer because I get the same crackling through my amp and my headphone amp. It's not my cable because I have tried two different cables and I have also used my headphone practice amp, which doesn't need a cable. All that's left is the bass and my body.

If the problem were caused by static, why should the static only make itself audible when I play a G2 or an A1?
Click to expand...

You are convinced that it is something with you or the bass. Three different techs haven't been able to reproduce your issue. I suggest you return to your favorite tech and YOU attempt to reproduce the sound. As you say, all that's left is the bass and your body. Three times your body has been left out of the chain and three times the sound wasn't reproducible. Ya think MAYBE it IS you?
 
Last edited:
#15
Thanks everyone so much for all your help so far. Your suggestions guided me to a discovery.

The tendency to get a crackling sound when playing the open G and D strings builds up after I have been playing for a while (maybe 10 or 20 minutes). I have a tone knob which is also a push-pull switch (TBH I don't actually understand what the push-pull action is supposed to do beyond that it changes the sound in some way). If I pull it out and push it back, the crackling eases off for a while.

However I have also noticed that when the knob is pulled out, the USB bus noise from my computer (I usually play through my computer rather than my amp out of mercy for my neighbours) via the audio interface, which is otherwise just a minor annoyance that can be dealt with using a touch of noise gate, becomes quite loud, but only to the extent that the knob is turned clockwise. If I turn the knob completely anticlockwise, there is no noticeable bus noise. I used to have a big problem with USB bus noise coming through the audio interface before I fixed the grounding of the motherboard (by re-seating the I/O plate), which suggests that there is some kind of grounding issue going on that causes the bus noise to become loud when the knob is pulled out. But I don't know whether or not this is connected to the crackling sound. The crackling sound is the main problem here that I need to fix because I already have workarounds for the bus noise if I need them.
 
#16
mumblecrust said:
Thanks everyone so much for all your help so far. Your suggestions guided me to a discovery.

The tendency to get a crackling sound when playing the open G and D strings builds up after I have been playing for a while (maybe 10 or 20 minutes). I have a tone knob which is also a push-pull switch (TBH I don't actually understand what the push-pull action is supposed to do beyond that it changes the sound in some way). If I pull it out and push it back, the crackling eases off for a while.

However I have also noticed that when the knob is pulled out, the USB bus noise from my computer (I usually play through my computer rather than my amp out of mercy for my neighbours) via the audio interface, which is otherwise just a minor annoyance that can be dealt with using a touch of noise gate, becomes quite loud, but only to the extent that the knob is turned clockwise. If I turn the knob completely anticlockwise, there is no noticeable bus noise. I used to have a big problem with USB bus noise coming through the audio interface before I fixed the grounding of the motherboard (by re-seating the I/O plate), which suggests that there is some kind of grounding issue going on that causes the bus noise to become loud when the knob is pulled out. But I don't know whether or not this is connected to the crackling sound. The crackling sound is the main problem here that I need to fix because I already have workarounds for the bus noise if I need them.
Click to expand...

Is this a Rickenbacker 4003?
 
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