ground hum with nylon strings

[gillento]

I have a bass that has a nasty ground hum when I am using black nylon strings (LaBella in my case).
It has a Split Coil PU.

Is there a way of getting rid of this?

 

[iiipopes]

Yes. When you use nylon tapewound strings, you de-couple the strings from the bridge ground, and it leaves the entire bass open as an ungrounded antenna attracting all sorts of hum and electrostatic noise.

You will get a plethora of posts after this one that either disagree with me, or partially agree with me, or provide partial solutions, like shielding the cavity, which will work to one degree or another, but never completely remove the noise.

But after playing bass for forty years plus, and having tried all of the proffered solutions which you will see in other threads, and still playing nylon wrap strings, there are two real solutions:

1) On my custom half-fanned P/J, I have a chrome covered pickup that I anchor my thumb on and ground it like a bridge plate. This makes the bass essentially the same as when the fingers are in contact with conventional strings through the bridge ground. That provides enough shunting of the noise to function as it wears Fender nylon tapewound strings.

2) On my 5-string Ibby party band bass, I need it to be as low noise as possible since it feeds D.I. into a digital board, which shows every nit, flaw, wart and inconsistency of what is fed into it. So I went with full EMG actives replacement pickups on that bass, with their internal grounding and greater than 100dB noise floor. Since the installation instructions for EMG actives explicitly state to not use a bridge ground, then it doesn't matter what strings are used with those pickups; I use La Bella White Tapes on that bass.

Good luck!

 

[gillento]

....

1) On my custom half-fanned P/J, I have a chrome covered pickup that I anchor my thumb on and ground it like a bridge plate. This makes the bass essentially the same as when the fingers are in contact with conventional strings through the bridge ground. That provides enough shunting of the noise to function as it wears Fender nylon tapewound strings.
.....

Good luck!

Thanks for your reply
Let me make sure I got this right: you have a chrome cover over the P PU and have a wire connected from the bridge to that cover? Or is the cover over the bridge?

 

[iiipopes]

Thanks for your reply
Let me make sure I got this right: you have a chrome cover over the P PU and have a wire connected from the bridge to that cover? Or is the cover over the bridge?

The P-pickup has been replaced with a Rickenbacker humbucker that has a chrome cover, and that chrome is grounded to the output jack the same way a bridge plate is on a conventional P-bass.

 

[Jonathan C]

Just installed the LaBella Copper Whites on my new Fender Elite Jazz (Noiseless 4 pickups). I'm getting some never heard before hum as well, though it would not be considered objectionable, I'd like it to vanish. If should accidentally touch one of the pickup poles? Loud hum! Zero hum with the original Fender Rounds or TI Jazz Flats. The Copper Whites are the sound I'm definitely loving!

 

[brianrost]

I've never understood why using a grounded bridge is so common instead of just grounding the pickups. EMG actives don't require a bridge ground nor do Danelectros, which are passive.

 

[DiabolusInMusic]

Just installed the LaBella Copper Whites on my new Fender Elite Jazz (Noiseless 4 pickups). I'm getting some never heard before hum as well, though it would not be considered objectionable, I'd like it to vanish. If should accidentally touch one of the pickup poles? Loud hum! Zero hum with the original Fender Rounds or TI Jazz Flats. The Copper Whites are the sound I'm definitely loving!

The hum you get from toucing your pole pieces indicates they need to be grounded (or covered with clear nail polish to prevent contact.)

Pole Piece Hum: A Grounding Tutorial

The hum you have since switching strings, does it stop when you touch any metal on the bass such as the bridge or controls? Are you certain there was no hum before changing strings? I am thinking your bass requires shielding.

 

[Jonathan C]

I will verify if it will go silent touching other metal on my bass. The bass did not have even the slightest hum at any setting passive or active before these strings were installed. Nothing is ever easy is it?

 

[GIBrat51]

I've never understood why using a grounded bridge is so common instead of just grounding the pickups. EMG actives don't require a bridge ground nor do Danelectros, which are passive.

I can't speak for your Danelectros, but all 3 of mine most certainly do have grounded bridges - and no hum. And for what it's worth, my Rogue VB-100 with a grounded tailpiece (no practical way to ground the bridge ) has had Roto 88 tapes on it for a few years now. Never had any hum that I can hear. Same for my Carvin LB-20 with La Bella tapes; grounded bridge, and no hum. I'm wondering how many of the people with this problem are playing a bass with a string-through bridge, rather than a top loader?

 

[Jonathan C]

My Fender Jazz Elite can be strung either way, I have it string through with the nylons. So if the ball of the string makes bridge contact, noise should go away, yes??

 

[iiipopes]

My Fender Jazz Elite can be strung either way, I have it string through with the nylons. So if the ball of the string makes bridge contact, noise should go away, yes??

Not necessarily. It may even increase, since the strings then become an ungrounded antenna. Typically, with conventional strings and a passive bass, the player's hands and body become the final ground to eliminate the noise. The nylon tape is an insulator that eliminates the direct metal-to-body contact, and hence the grounding.

I would keep it strung body-through and shield the passive bass control cavity.

Another option that I have on my mid pickup on my passive bass with nylon tapewounds is to install a grounded chrome pickup cover , so my thumb anchor also functions as the string ground like a bridge ground conventionally does.

Or the final solution, which I use on my gigging party band bass, is to go EMG actives, which are internally grounded, don't use a bridge ground, and have a greater than -100dB noise floor. The string configuration is then a moot point.

 

[brianrost]

I can't speak for your Danelectros, but all 3 of mine most certainly do have grounded bridges

OK, I stand corrected. I opened my two Danos. I did find grounding wires but they don't directly contact the bridge (which floats over the body), they contact the one of the screws that the bridge sits on. It's not visible from the outside that there is any grounding. In both of mine the it just so happens that the connection is open. Probably because there is no solder connection...it depends on physical contact with the screw. So my strings are not grounded and the instruments do not hum.

 

[Jonathan C]

Not necessarily. It may even increase, since the strings then become an ungrounded antenna. Typically, with conventional strings and a passive bass, the player's hands and body become the final ground to eliminate the noise. The nylon tape is an insulator that eliminates the direct metal-to-body contact, and hence the grounding.

I would keep it strung body-through and shield the passive bass control cavity.

Another option that I have on my mid pickup on my passive bass with nylon tapewounds is to install a grounded chrome pickup cover , so my thumb anchor also functions as the string ground like a bridge ground conventionally does.

Or the final solution, which I use on my gigging party band bass, is to go EMG actives, which are internally grounded, don't use a bridge ground, and have a greater than -100dB noise floor. The string configuration is then a moot point.

The Fender Jazz Elite uses "Noiseless Version 4" pickups and is switchable active/passive. It was a 100% silent bass before the nylons went on it whether I touched the strings or not.

 

[Abner]

Not necessarily. It may even increase, since the strings then become an ungrounded antenna. Typically, with conventional strings and a passive bass, the player's hands and body become the final ground to eliminate the noise. The nylon tape is an insulator that eliminates the direct metal-to-body contact, and hence the grounding.

I would keep it strung body-through and shield the passive bass control cavity.

Another option that I have on my mid pickup on my passive bass with nylon tapewounds is to install a grounded chrome pickup cover , so my thumb anchor also functions as the string ground like a bridge ground conventionally does.

Or the final solution, which I use on my gigging party band bass, is to go EMG actives, which are internally grounded, don't use a bridge ground, and have a greater than -100dB noise floor. The string configuration is then a moot point.

I'm sorry, but you are making a very common mistake. Your bass is not grounded through you — rather you are grounded through your bass (as long as your bass is grounded through your amp/di/whatever, which it usually is). Unless, of course, you have nylon strings on it.

-Alex

 

[iiipopes]

I'm sorry, but you are making a very common mistake. Your bass is not grounded through you — rather you are grounded through your bass (as long as your bass is grounded through your amp/di/whatever, which it usually is). Unless, of course, you have nylon strings on it.

-Alex

Fine. Whatever. Semantics. The point being is the discussion about the noise.

 

[GIBrat51]

OK, I stand corrected. I opened my two Danos. I did find grounding wires but they don't directly contact the bridge (which floats over the body), they contact the one of the screws that the bridge sits on. It's not visible from the outside that there is any grounding. In both of mine the it just so happens that the connection is open. Probably because there is no solder connection...it depends on physical contact with the screw. So my strings are not grounded and the instruments do not hum.

Actually, your strings are grounded. They're touching the bridge, which is touching the screw; which is touching the ground wire - just like mine. I agree that it's not the best grounding system in the world - but it does work. Try taking that wire off the screw sometime, and see what happens. My Danos hum like crazy when I do that... My Fender P-Bass is almost as primitive; there's a ground wire under the bridge that just touches it to make the ground connection. But, at least Fender sanded a little spot of chrome off the bridge, to make the contact better...

 

[brianrost]

No, mine are not grounded...I checked with a mulltimeter.

On one the end of the wire that was probably once soldered to a potentiometer is floating inside the body so there's no physical connection at all. On the other, the wire is soldered to the pot but there is no continuity to the screw or the bridge. Possibly due to some work done on the instrument in the past, corrosion, who knows. So they are supposed to be grounded but aren't.

Anyway, there's no hum because the pickup was properly shielded in the first place. Are yours reissues? Mine are late 50s early 60s Silvertones.

 

[GIBrat51]

Yes, mine are reissues... 'cause there are no lefty originals...