Squire VM Fretless Jazz Noise Issue - DD Pickups

[portishead1]

Hi All;

I have searched high and low and have not found a definitive answer as to what could be causing the buzz on this bass. The buzz goes away when I touch the strings, the control plate or the shell of the input plug. I also took the electronics out and the wiring is correct. I tried running a copper ground wire from the bridge to the ground connection point on the pots and the noise does not go away. I also tried running connections to the pot grounds from the control plate and can't get it to stop. This bass does this on two different amps with two different cables. I have another VM Jazz bass and it's dead quiet on both amps using the same cables. On several threads, some have said replacing the pickups was the only answer to this, another said changing the tone pot worked which I'm not convinced would fix it. I don't want to waste a lot of time troubleshooting and shielding if it's just going to result in it being the pickups as others have said.

 

[mcnach]

what's the shielding like? and is it grounded?

 

[sunbeast]

Sounds like a lack of shielding (or if there is shielding perhaps not grounded correctly)

 

[portishead1]

No shielding in the controls or pup cavities, which is the same on my other Jazz bass which is quiet. Is shielding the cavities the only way to try and solve this?

 

[tpa]

I also have this VM fretless Jazz. I did two small things. (1) Shielding of cavities with conductive paint a (2) reduced the loops of the wires from the pickups. Originally the relatively generous amount of wire from especially the neck pickup was stuffed in in a messy manner so they formed loops. I changed so the wires run close to one another (twisted around each other). The paint was the StewMac brand. Some time in future I may change pots to an non-scratchy type but it doesnt matter that much as they typically are either full on or full off

 

[tpa]

... Is shielding the cavities the only way to try and solve this?

Guess so. I have had two VM Jazz fretless. The first one neede the same medicine. Small job. Completely worth it.

 

[sunbeast]

No shielding in the controls or pup cavities, which is the same on my other Jazz bass which is quiet. Is shielding the cavities the only way to try and solve this?

If the buzz goes away when you touch ground (strings, bridge, or other metal connections), and assuming you have a decrease in low frequency hum with both pickups on full, then it isn’t typical single-coil noise that new pickups might decrease. Your other VM Jazz has the same DD pickups, using same pickup settings and same cables, etc? And no added shielding to the pickups either or other electronic upgrades (even a different tone setting that might be rolling off some of the buzz)?

 

[portishead1]

The buzz doesn't attenuate with both pickups at varying volumes and both up full. The buzz get's louder/softer depending on independent/together pickup volume. The tone pot makes it go away when it's all the way down. I cleaned the pots with de-oxit an it didn't change anything. My other jazz is a Squire Classic Vibe 70s with the stock Fender designed pickups I believe. It's quiet and sounds just like it should. Wanted to rule out any other electronic issues before shielding or pickup change.

 

[skycruiser]

I've used those same DD pickups and didn't have any noise when both were set to equal volume. Do you have an ohm meter? I would plug in a cable but disconnect the amp end of the cable. Put one of the meter leads on the ground contact of the unconnected cable end. Verify that you get <100 ohms when you touch the bridge, strings, control plate, each potentiometer chassis, and the ground lead on the output jack.

I have not found shielding to be very helpful with single coil pickup noise when they are not at equal volume. And it should be dead quiet, even without shielding (in most environments), when the pickups are set to equal volume.

 

[sunbeast]

The buzz doesn't attenuate with both pickups at varying volumes and both up full. The buzz get's louder/softer depending on independent/together pickup volume. The tone pot makes it go away when it's all the way down. I cleaned the pots with de-oxit an it didn't change anything. My other jazz is a Squire Classic Vibe 70s with the stock Fender designed pickups I believe. It's quiet and sounds just like it should. Wanted to rule out any other electronic issues before shielding or pickup change.

Humbuckers (or a pair of reverse-wound single coils as in a Jazz bass when both are turned up all the way) are good at eliminating EMI, which is lower-frequency "hum" such as that coming from the wall power and power transformers of everything around us.

"buzz" on the other hand is usually high-frequency noise that is associated with radio-frequency interference, and even humbucking pickups are not great at eliminating it completely as each coil would have to see the signal equally and RFI is very directional (this sort of noise comes from all sorts of the devices we have everywhere, from lights to faders to monitors, to phones and computers, etc). Only proper grounded shielding is totally effective at decreasing this kind of noise to a large degree when it is present. My guess is that your other Squier bass or its pickups have some form of shielding (even painted cavities), though even different pickups of the same type can pass on noise differently- I know some modern Squiers are shielded from the factory, while I don't believe the old VMs were (are the cavities of either of your basses painted black?)

 

[portishead1]

So I measured all the resistance and everything came back single digits or less. I also took a piece of copper wire and tested all the ground connections to make sure it wasn't a bad link somewhere and also connected a second test ground from the bridge to the electronics which didn't help. I saw a pair of new Fender Original USA Jazz pickups on my local classifieds for $60US and swapped out the DDs for them and......Gaaahhh!! Buzz still there and just as loud!!

Bypassing the tone pot completely was the only way it would stop so I finally removed the tone pot from the electronics plate and a piece of black thread was sandwiched in there somewhere. I cleaned the pot and all washers/nuts with de-oxit and reseated and that was the source of the buzz FFS!

Problem solved and these new Fender Jazz pickups were worth the $60 and time invested installing them. They don't seem to be as hot as the Duncans but speak more in the midrange. They also came with grounding plates for the pickups cavities which is probably an improvement from the nothing under the Duncans.

Thanks for everyone who replied!

 

[DiabolusInMusic]

Your bass requires shielding. A hum that stops when you touch metal/strings/bridge indicates RF interference. This is resolved through shielding. Those "grounding plates" in the pickup cavities are 60s style shielding. Not the most efficient but they can make an impact on noise. Always double check the ground wire when adding shielding too.

60hz hum, the noise stopped by humbuckers/balancing pickups, can only be stopped with an even number of coils.

 

[skycruiser]

So I measured all the resistance and everything came back single digits or less. I also took a piece of copper wire and tested all the ground connections to make sure it wasn't a bad link somewhere and also connected a second test ground from the bridge to the electronics which didn't help. I saw a pair of new Fender Original USA Jazz pickups on my local classifieds for $60US and swapped out the DDs for them and......Gaaahhh!! Buzz still there and just as loud!!

Bypassing the tone pot completely was the only way it would stop so I finally removed the tone pot from the electronics plate and a piece of black thread was sandwiched in there somewhere. I cleaned the pot and all washers/nuts with de-oxit and reseated and that was the source of the buzz FFS!

Problem solved and these new Fender Jazz pickups were worth the $60 and time invested installing them. They don't seem to be as hot as the Duncans but speak more in the midrange. They also came with grounding plates for the pickups cavities which is probably an improvement from the nothing under the Duncans.

Thanks for everyone who replied!

Great, glad to hear you found the source of the problem!

 

[sunbeast]

So I measured all the resistance and everything came back single digits or less. I also took a piece of copper wire and tested all the ground connections to make sure it wasn't a bad link somewhere and also connected a second test ground from the bridge to the electronics which didn't help. I saw a pair of new Fender Original USA Jazz pickups on my local classifieds for $60US and swapped out the DDs for them and......Gaaahhh!! Buzz still there and just as loud!!

Bypassing the tone pot completely was the only way it would stop so I finally removed the tone pot from the electronics plate and a piece of black thread was sandwiched in there somewhere. I cleaned the pot and all washers/nuts with de-oxit and reseated and that was the source of the buzz FFS!

Problem solved and these new Fender Jazz pickups were worth the $60 and time invested installing them. They don't seem to be as hot as the Duncans but speak more in the midrange. They also came with grounding plates for the pickups cavities which is probably an improvement from the nothing under the Duncans.

Thanks for everyone who replied!

Interesting- I wonder if the tone pot wasn’t fully grounding itself on the control plate. Were any of the grounds from the circuit soldered to the back of the tone pot? Also if the “thread” was something conductive there could have been some internal connection acting as an antenna. The pots are by far the weakest link in Squier VM/CV basses in my opinion, and the first thing I upgrade (even before the pickups- I actually love those old Duncan-designed Jazz pickups and have bought several sets over the years from people who have “upgraded” them haha! They are nearly identical to the Duncan SJB-1 pickups).

 

[portishead1]

Hi Sunbeast - No grounds are connected to the tone pot. Reseating it is a bit puzzling as I did try a "wired" ground to it and also measured resistance between the tone pot body and ground and there was nothing and the noise didn't stop until I reseated it.

 

[sunbeast]

Hi Sunbeast - No grounds are connected to the tone pot. Reseating it is a bit puzzling as I did try a "wired" ground to it and also measured resistance between the tone pot body and ground and there was nothing and the noise didn't stop until I reseated it.

I’ve never liked the grounding scheme of the typical Jazz plate, and always ground all the pots separate of the mechanical connection to the metal plate. Just much more trustworthy of a connection. Without a ground the capacitor and potentially even pot casing of the tone pot could indeed act as a noise antenna