So your bass has a hum

[DiabolusInMusic]

I have a Precision bass. My bass has 2 hums. The first hum is loud and goes away when i touch the metal parts. According to you it'll be shielding issue. I havent fix it yet.
But there is another hum occuring at the same time. At first i didnt realize it but when I turn up the amp volume at max, it becomes apparent. As I touch the metal parts, the main hum goes away but the bass does not go quiet. The 2nd hum is still there, and it seems to get louder when i pluck the strings. I tested to pluck and mute the string right away, the hum keeps on and then fade away until it reduce to the initial loudness. My bass is P bass, and this is not 60 cycle hum.
Is there anyone experiencing the same problem. The 2nd hum is very strange and I havent found any information about it.
I havent done any big changes to my bass. Just one time, i put a tiny piece of cloth under the trebble pu to raise it up, because it cant be raised by adjust the screw.
The 2nd hum is much quieter in comparison to the first hum. But it is still make me frustrated, that even if I shield up everything my bass will still have hum. Can anyone help me out?

From the sounds of it, your bass will require shielding either way. Doublecheck the ground wire under the bridge when you do the shielding. A hum that gets louder when you touch metal/strings/bridge indicates a grounding issue. See if the hum persists after checking the ground. If hum is still happening, I would recommend making a new thread about your issue to get more views. Please tag me in the post, if that is the case.

 

[deeruss]

Hello,
Thank you for this very useful guide.

I de-solder all the previous connections on my p-bass and re-solder them using this schematic :

I removed 2 wires as the aluminium tape is now connecting the knobs and the output jack together.

It is ok ?

My bass is now very quiet, there's a tiny bit of hum when I don't touch the strings.
Could it be solved with conductive paint ?

 

[d00dr]

I recently just swapped out my Lollar Overwound for a Curtis Novak PB-90. When I was putting the bass together, I did not have immediate access to any shielding material so I skipped it. The bass was dead quiet with the Lollar installed but now that I’ve installed the Novak, I have a terrible buzz that sounds like it is a shielding issue. It becomes more and more noticeable as I turn the tone knob up and becomes less noticeable when I touch my amp (Genzler Magellan 800.) I have two other P’s (one with a Seymour Duncan SPB-3 QP and one with a Fender CS ‘62,) neither of which are shielded, and I have no noise issues with either of those. Is it possible that the pickup is causing the issue? Do certain pickups require cavities to be shielded and others not?

 

[Joe Nerve]

Being someone who used to absolutely abhor any noise that came out of my bass, I found an effortless way to get rid of it. All it takes is patience and commitment.

The commitment is to never ever wear earplugs, despite the silly warnings of all those who care about you.

In time most of that annoying hum simply disappears on it's own. No need for all the complicated electronic BS presented in this thread.

I know from experience.

 

[DiabolusInMusic]

Hello,
Thank you for this very useful guide.

I de-solder all the previous connections on my p-bass and re-solder them using this schematic :
View attachment 3007641
I removed 2 wires as the aluminium tape is now connecting the knobs and the output jack together.

It is ok ?

My bass is now very quiet, there's a tiny bit of hum when I don't touch the strings.
Could it be solved with conductive paint ?

Thanks for your kind words. Grounding out from the pickguard is an option and it sounds like everything is working. And yes, shielding with conductive paint would resolve your last bit of hum.

I recently just swapped out my Lollar Overwound for a Curtis Novak PB-90. When I was putting the bass together, I did not have immediate access to any shielding material so I skipped it. The bass was dead quiet with the Lollar installed but now that I’ve installed the Novak, I have a terrible buzz that sounds like it is a shielding issue. It becomes more and more noticeable as I turn the tone knob up and becomes less noticeable when I touch my amp (Genzler Magellan 800.) I have two other P’s (one with a Seymour Duncan SPB-3 QP and one with a Fender CS ‘62,) neither of which are shielded, and I have no noise issues with either of those. Is it possible that the pickup is causing the issue? Do certain pickups require cavities to be shielded and others not?

If you have a hum that stops when you touch the amp, I would double check your 1/4" cable. I have had failed cables cause some strange noise issues. If the noise stops when touch metal on the bass, it likely needs shielding. I would double check the ground wire under the bridge first though; ensure the wire is making good contact before you do more troubleshooting.

As far as why one pickup seems to get it worse, certain pickups will highlight different frequencies better than others. Also, just because a bass is not currently experiencing RF interference does not mean the bass is not susceptible to it, same with 60hz noise and single coils. RF interference and 60hz hum are not raging in every single environment. That being said, my first time really addressing shielding stemmed from dropping in some QPs which hummed like hell. Bar lights and neon signs are a sure-fire way to get a bunch of unwanted noise.

 

[d00dr]

If you have a hum that stops when you touch the amp, I would double check your 1/4" cable. I have had failed cables cause some strange noise issues. If the noise stops when touch metal on the bass, it likely needs shielding. I would double check the ground wire under the bridge first though; ensure the wire is making good contact before you do more troubleshooting.

As far as why one pickup seems to get it worse, certain pickups will highlight different frequencies better than others. Also, just because a bass is not currently experiencing RF interference does not mean the bass is not susceptible to it, same with 60hz noise and single coils. RF interference and 60hz hum are not raging in every single environment. That being said, my first time really addressing shielding stemmed from dropping in some QPs which hummed like hell. Bar lights and neon signs are a sure-fire way to get a bunch of unwanted noise.

Im thinking it’s not the cable as the other two basses are still dead silent with the same cable running through the same amp. And the bridge ground wire is making great contact in there. It’s really quite strange to me though; the noise seems to almost completely disappear when I touch the top of the volume knob or when I touch the metal casing of the amp. Since everything is grounded to back of the volume pot, perhaps I have a bad ground connection somewhere in there?

 

[DiabolusInMusic]

Im thinking it’s not the cable as the other two basses are still dead silent with the same cable running through the same amp. And the bridge ground wire is making great contact in there. It’s really quite strange to me though; the noise seems to almost completely disappear when I touch the top of the volume knob or when I touch the metal casing of the amp. Since everything is grounded to back of the volume pot, perhaps I have a bad ground connection somewhere in there?

If the noise only stops when you touch a single knob, I would focus on that pot's grounding. Shielding issues would impact the entire bass and would stop when you touched any metal, right up to the tuners.

 

[devnulljp]

Being someone who used to absolutely abhor any noise that came out of my bass, I found an effortless way to get rid of it. All it takes is patience and commitment.

The commitment is to never ever wear earplugs, despite the silly warnings of all those who care about you.

In time most of that annoying hum simply disappears on it's own. No need for all the complicated electronic BS presented in this thread.

I know from experience.

Doesn't it just get replaced by a high pitched WEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEE noise over time?

 

[cholyoke]

Thank you for this guide. The humming is gone!

 

[DiabolusInMusic]

Thank you for this guide. The humming is gone!

Glad to hear that it helped. I sleep easier knowing that one more bass is functioning properly.

 

[1nterest1ng]

I've shielded my bass using aluminium foil and checked all connections, and while the hum has become quieter, it persists. What can I do?

 

[DiabolusInMusic]

I've shielded my bass using aluminium foil and checked all connections, and while the hum has become quieter, it persists. What can I do?

Nothing major, it just sounds like you need some more shielding somewhere. While it works, aluminum tape is not the best material for this application. I'm guessing you have shielded the pickups as well as the cavities. Do you have an ohmmeter to check where your shielding may be weak or losing a connection?

 

[1nterest1ng]

Nothing major, it just sounds like you need some more shielding somewhere. While it works, aluminum tape is not the best material for this application. I'm guessing you have shielded the pickups as well as the cavities. Do you have an ohmmeter to check where your shielding may be weak or losing a connection?

Yeah, I checked the connections with an ohmmeter, and it's all connected.

 

[rufus.K]

I've shielded my bass using aluminium foil and checked all connections, and while the hum has become quieter, it persists. What can I do?

got pix?

 

[DiabolusInMusic]

Yeah, I checked the connections with an ohmmeter, and it's all connected.

Where is the resistance highest? That is likely where you getting issues. I would suggest double checking your ground wire as well.

 

[1nterest1ng]

Where is the resistance highest? That is likely where you getting issues. I would suggest double checking your ground wire as well.

I've checked the ground wire and the connections have little resistance. I have no clue where the issue is. Could the problem be outside the bass or something?

 

[BlueTalon]

I've checked the ground wire and the connections have little resistance. I have no clue where the issue is. Could the problem be outside the bass or something?

Single coil pickups?

 

[1nterest1ng]

Single coil pickups?

It's the kind of hum that goes away when the strings are touched. Also, it's a PJ and both pickups have this issue.

 

[DiabolusInMusic]

I've checked the ground wire and the connections have little resistance. I have no clue where the issue is. Could the problem be outside the bass or something?

There could be an issue with your cables or amp but it is more often the bass.

 

[BlueTalon]

OK then. What exactly do you mean by "little resistance"? Also, photos would probably be helpful.

I've checked the ground wire and the connections have little resistance. I have no clue where the issue is. Could the problem be outside the bass or something?