Are some instruments un-shieldable/groundable

[alex1fly]

I have two basses that buzz. Both have been in to a luthier over the last year for help chasing down these buzzes, and both luthiers (one very pro, one starting out) were able to reduce the buzz but not get rid of it. They are different kinds of buzz, too - one bass has constant background mid frequency hiss that changes in volume when I rotate my orientation towards the amp, the other bass has a high frequency buzz that reduces in volume when I touch the strings or bridge but never fully goes away.

Bass #1 - Squier Bronco, stock pickup
Bass #2 - P clone, Bill Lawrence P pickup

What gives? Are some instruments just going to buzz no matter what?

 

[Mincer]

I have had even well-shielded guitars hum sometimes....usually in questionably-wired clubs, or near a cell tower. Bad/cheap cables cause this, too. Do they buzz in different locations, through different amps & cables?

 

[alex1fly]

I have had even well-shielded guitars hum sometimes....usually in questionably-wired clubs, or near a cell tower. Bad/cheap cables cause this, too. Do they buzz in different locations, through different amps & cables?

Its literally me sitting in the same spot and swapping instruments around. Same cable, same amp, same chair even.

 

[solspirit]

EMF, solar flares, is your house well grounded?

 

[alex1fly]

EMF, solar flares, is your house well grounded?

I think its particular to these two basses. My other two basses don't buzz at all (1 active EMG, 1 passive EMG). Nor do my guitars with their various pickups and switching systems.

I guess the real question I'm getting at is if I've already taken these puppies to professionals should I just accept them as they are or keep trying to make them better?

 

[idsnowdog]

You can shield most instruments. What I have seen is many guitars have shielding paint but it isn't grounded and their wiring has ground loops straight from the factory.

 

[GuitarStv]

Most semihollow guitars are pretty close to impossible to shield. You can get them pretty quiet by using shielded wire and humbuckers, but they're always going to be a little more prone to noise because of how little access you have to the internals to put shielding.

 

[ErikH]

My SUB Ray4 is a slight buzz until I touch the strings or bridge (it's wired passive). I've had it open several times and used a meter to verify that all grounds are solid and they are. There is no reason it should buzz at all. So, my next plan is to put some tape on the back side of the metal control plate and in the holes so it's not used as a ground plane. Then I'll use shielded wire to connect the pots / jack to the ground plane.

 

[alex1fly]

My SUB Ray4 is a slight buzz until I touch the strings or bridge (it's wired passive). I've had it open several times and used a meter to verify that all grounds are solid and they are. There is no reason it should buzz at all. So, my next plan is to put some tape on the back side of the metal control plate and in the holes so it's not used as a ground plane. Then I'll use shielded wire to connect the pots / jack to the ground plane.

A-ha! Part of me hopes you fail so I get my answer of "yes some instruments cannot be properly shielded" but really the other 80% wishes you massive success. Lol

 

[NegativeEase]

Are we sure that the amplifier pre-amp, house power isnt the issue?

Have you listened to both bases into a DC powered headset or something battery powered?

 

[Clint 55]

It's been my experience that some instruments seem more prone to buzz. My bass is like that. I just do my due diligence with shielding and soldering ground wires. Make sure to solder a ground wire to the bridge because that acts as a chassis ground to help dissipate noise. Don't be sheisty, get in there and solder a wire to the bridge. It is more effective than only contact. Scuff up the bridge, apply flux, and use a high powered iron with enough heat to bond the solder to the bridge.

 

[beaubrummels]

The Bronco, and I believe the Lawrence, are single coil. always subject to buzz/hum. The EMGs are humbucking, no?

 

[ErikH]

A-ha! Part of me hopes you fail so I get my answer of "yes some instruments cannot be properly shielded" but really the other 80% wishes you massive success. Lol

LMAO!!! Mine started off with active electronics. Even after I swapped the pickup for a SMB-4a it stayed quiet. Wired in parallel too. Will post an update here after doing the work.

 

[GuitarDoc]

You can shield most instruments. What I have seen is many guitars have shielding paint but it isn't grounded and their wiring has ground loops straight from the factory.

Ground loops? In a guitar? Nope.

 

[AlexR]

Some have longer runs of wire that attract RF. Others keep it shorter, or have cavities that allow for full faraday cage setup.

 

[uOpt]

I have two basses that buzz. Both have been in to a luthier over the last year for help chasing down these buzzes, and both luthiers (one very pro, one starting out) were able to reduce the buzz but not get rid of it. They are different kinds of buzz, too - one bass has constant background mid frequency hiss that changes in volume when I rotate my orientation towards the amp, the other bass has a high frequency buzz that reduces in volume when I touch the strings or bridge but never fully goes away.

Bass #1 - Squier Bronco, stock pickup
Bass #2 - P clone, Bill Lawrence P pickup

What gives? Are some instruments just going to buzz no matter what?

Is either one active? A preamp can cause buzzing even in a perfectly shielded instrument, e.g. with a defective filter cap.

Defective pots can do it. Try testing without the pots in the circuit.

The first bass, does the noise get better when you touch the strings? If not your bridge ground wire is defective.

In general, the answer to your question is "no". It is not possible to make a passive, humbucker bass that can't be shut up by shielding.

 

[alex1fly]

Did some experimenting.

Squier Bronco I thought was because of single coil buzz - the pickup is a Strat pickup, after all. But I swapped a humbucker in and the buzz is still there. But last night it was less intense than the night before (fewer radio waves) so I'm thinking its just poorly shielded even though the cavity is painted and everything seems to be in place. Buzz went away actually when I loosened the pickguard which is weird.
P Copy is just poorly grounded. Buzz goes away when I touch the bridge. Luthier was able to reduce the amount of buzz but its still there.

Several months ago I took another bass and put an EMG Geezer solderless system in. Absolutely no buzz anymore. I like fixes like that - just solve the problem, TYVM

 

[AlexR]

Most likely the EMG set sports shielded hookup wire as well as coil/pickup shielding.
Noise that goes away when touching the strings just means the string grounding is working properly. But passive or unshielded systems need that help, its simply up to the player to learn how to use the instrument the best to make it work.

 

[beaubrummels]

Did some experimenting.

Squier Bronco I thought was because of single coil buzz - the pickup is a Strat pickup, after all. But I swapped a humbucker in and the buzz is still there. But last night it was less intense than the night before (fewer radio waves) so I'm thinking its just poorly shielded even though the cavity is painted and everything seems to be in place. Buzz went away actually when I loosened the pickguard which is weird.
P Copy is just poorly grounded. Buzz goes away when I touch the bridge. Luthier was able to reduce the amount of buzz but its still there.

Several months ago I took another bass and put an EMG Geezer solderless system in. Absolutely no buzz anymore. I like fixes like that - just solve the problem, TYVM

Loosening the pickguard making the buzz go away tells me the pickguard might have shield that is touching a hot wire? Or it's not shielded and accumulated static is discharging through touching a hot or ground wire? (the latter is a long shot guess. My first thought is the pickguard is touching a hot wire when fastened down.)

 

[ErikH]

A-ha! Part of me hopes you fail so I get my answer of "yes some instruments cannot be properly shielded" but really the other 80% wishes you massive success. Lol

Well, no luck in my attempts. I shortened some wires, redid a few solder points. Every point is 100% when I check them with the meter. There is some shielding in the cavity but it's not a lot. The buzz doesn't even change or go away when I take off the control plate. Bridge ground is solid, verified with a meter and even using a wire with alligator clips; one end on the bridge, the other at a ground point (like the jack or volume pot). Zero change. So, I'm going to leave it as-is for now until I can shield the cavity better and maybe even get a couple replacement 250K pots. I've run across this in a guitar before and a pot was not quite right so it would buzz no matter what. It's not a lot, but it's noticeable. This is the only bass or guitar I have with a metal control plate.