Does shielding affect Stacked pickups?

[PicoRiveraTele]

Re: Does shielding affect Stacked pickups?

Relying on foil to ground the components is effective enough for the guitar to function, but in most cases not enough for it to be completely quiet. If you want to eliminate the possiblity of the noise being caused simply by user error, you must ground each of your electronics with a wire. And have that connected to your chassis ground of the bridge and body.

That's not true. The foil connection is sufficient. The bigger issue is that if the switch or pot becomes loose, or if there is significant oxidation in the control cavity, the connection between the foil and the component will lose electrical continuity.

 

[PicoRiveraTele]

Re: Does shielding affect Stacked pickups?

Recently installed Classic Stack Plus STK-S4 in neck $ middle and Vibtage Hot Stack STK-S7 in the bridge. The neck pickup is dead silent. The middle pickup is very quiet but not silent. The bridge is quieter than a standard single coil, but it definitely is still noisy.

I have checked and double checked the wiring, grounding, etc...could the copper shielding in the guitar body be hurting instead of helping? The silent pickup is way down in the pickguard, the noisiest is the one sticking up most. Could the copper be blocking EMI noise from reaching the noise cancelling coil???

I think what you ought to consider doing is swapping the place of the bridge and the neck pickups, and see if the hum follows the position, or the pickup. If it follows the pickup, return it for a new one. Usually a stack achieves perfect hum cancelling by simply having identical top and bottom coils, but I see on their product page http://www.seymourduncan.com/pickup/classic-stack-plus-set "and, at the end of the production process, we fine tune each pickup for maximum noise cancelation" , so it appears that there is an extra step the in their process where something could go wrong, and imperfect hum cancelling might actually result instead.

 

[Clint 55]

Re: Does shielding affect Stacked pickups?

Yes it is true. Why are people so averse to grounding their circuit?

 

[PicoRiveraTele]

Re: Does shielding affect Stacked pickups?

Yes it is true. Why are people so averse to grounding their circuit?

The foil itself has to be grounded somehow of course, but if, for example, a selector switch is already making contact with the foil on the pick guard, it blocks electrostatic noise as well as if you had connected a ground wire to it, because the resistivity of the foil is very low.

 

[Clint 55]

Re: Does shielding affect Stacked pickups?

In addition to blocking interference, it also has to do with having everything solidly connected to the earth ground from the jack and the chassis ground of the bridge (and body) so noise can dissipate.

 

[toowrongfoo]

Re: Does shielding affect Stacked pickups?

I'm only going to say this, take for what it's worth:

Recently I just rewired a strat with just a bit of foil shielding on the pickgaurd, and it's fine. They are stack pups (fender N3's)

Just FYI.

 

[Clint 55]

Re: Does shielding affect Stacked pickups?

Yup. And I can dime my amp with my true single coils with zero noise. Just FYI.

 

[DavidRavenMoon]

Re: Does shielding affect Stacked pickups?

There's two kinds of noise, magnetic field noise, which is the low pitched hum, and electrical field noise, which is the high pitched buzz.

Shielding only blocks magnetic field noise. It doesn't get rid of hum. Humbuckers only cancel magnetic field noise. Ideally you want to shield humbuckers.


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[DavidRavenMoon]

Re: Does shielding affect Stacked pickups?

I hope someone with a bit more tech. knowledge chimes in but... I still feel like it could be due to an imbalance between the lower and upper coils that is made more evident when the "live" coil is made hotter; imperfect noise cancellation? The bottom coil is apparently "tuned to cancel hum" individually for each pickup, but I wonder if there are limits to the design...

That could do it, but you can unbalance coils quite a bit and still have sufficient hum cancellation. Some newer stacked pickups copy the Kinmann method (read: they infringe on his patents) and use a lower resistance lower coil with higher inductance, and also steel shielding for the upper coil and none for the lower coil.

The lower resistance bottom coil reduces the typical low frequency phase cancelation in stacked pickups


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[Mincer]

Re: Does shielding affect Stacked pickups?

A properly wired modern Stack pickup is really quiet. As quiet as a humbucker. I would certainly break the wiring up into individual parts for testing. As a whole, there is much that could be causing the noise. Test each pickup by itself. Test the preamp.

 

[toowrongfoo]

Re: Does shielding affect Stacked pickups?

That's kinda what I was getting at, stacked pups are supposed to be, by nature, quiet. If they are not, then there is generally a grounding issue/etc.

 

[dotsdad]

Re: Does shielding affect Stacked pickups?

I finally gave up and called customer service. They also recommended taking it out of the guitar and plugging straigt to jack. Still hummed....it was quiet when i turned it ne way, got grodually louder and softer as i mved it. Almost like it cancelled emi fron thr top but not the sides. In any case, Im gonna RMA it for an s4, as they are much quieter. I guess it is the unbalanced coils. Shame too, because the s7 did sound great (other than the buzz of course)

 

[Mincer]

Re: Does shielding affect Stacked pickups?

Hmm, I don't think it is the unbalanced coils, as mine is dead silent. Either something is wrong with the wiring inside the pickup, or the AC inside the house. Had you tested it in another location?

 

[dotsdad]

Re: Does shielding affect Stacked pickups?

You have a Vintage Hot Stack that is dead silent? I thought you were a Classic Stack Plus fan?

Classic Stack Plus were silent in another guitar that I had to sell a while back. They're quiet in this guitar too. The VH stack is the only one that's is noisy.

My man cave is EMI hell : Ceiling fan, CRT, and track lights on a dimmer switch! This is where I use this particular guitar though so it needs to sound good in that encironment. The EMI buzz is why I want to use stacks in this guitar instead of SSLs.

 

[Clint 55]

Re: Does shielding affect Stacked pickups?

Ground everything with wires including the switch and solder a ground wire to the bridge and another one to a screw mounted in the body.

 

[Jermo3178]

Re: Does shielding affect Stacked pickups?

I have an S7 an s4.. not used them a whole lot yet, but they seem to be dead silent. I've only used them twice so far though.... Only thing I have heard is the dang electric fence popping in the amp.

 

[Mincer]

Re: Does shielding affect Stacked pickups?

Yeah, big electrical charges, or things like CRT monitors or neon...if you are close enough...can come through any pickup. Being close to a cell tower can do it too- you get a weird series of beeps.

 

[Clint 55]

Re: Does shielding affect Stacked pickups?

That's why u gotta take extra steps to ground the circuit.

 

[Jermo3178]

Re: Does shielding affect Stacked pickups?

Electric fence pops through on anything... The only way to stop that is unplug it... I'm OCD I shield paint everything.