noiseless pickup hum mystery!!!!!

[Ron S]

Hi

Has anyone ever experienced anything like this with noiseless pickups....?

I installed a set of vintage noiseless pickups in my tele this week and found that the bridge pickup still hums like a single coil. The neck pickup is deathly silent while the bridge seems to have that 60 cycle hum like my regular teles.

I had a set of Dimarzio Area T's lying around and installed them...same issue, the bridge hums too while the front pickup is silent. The bridge plate is earthed and all is wired correctly. I've shown it to a guitar tech who is as dumbfounded as I am.

Any thoughts?

Cheers

[Eric Daw]

The wire going from the neck pickup to the electronics is a lot longer than the wires between the bridge pickup and the electronics. The longer wire, if not shielded (and it's usually not), is enough to pick up a little hum. It shouldn't have the hum of a single coil, though. If it's a dual coil pickup, or a stacked pickup, you may have one dead coil. You may also have wired it wrong, but I suppose you double checked all that.......

EDIT: just re-read your post and realized I read it backwards. It's the bridge pickup that's humming. Nevermind!

It's gotta be either a defective pickup or a botched installation.

[Bartholomew3]

Sounds like a problem in the switch that isn't obvious - or maybe the ground wire to the bridge has a break in it, possibly got pulled during installation ?

[audiohatemchine]

There's actually a tiny little angry irishman in your bridge pickup screaming at you. Except because he's so tiny, all you're hearing is that hum.








... No?

[Ron S]

Thanks guys. Yeah, checked all of that (even the Irishman, def free of Leprechauns etc)

I've just swapped the control plate out for another one including the output jack and leads, still got it with both noise cancelling bridge pups (Dimarzio and VN)

Totally stumped and about to buy a les paul (only joking)

[Ron S]

Quick update, bizarrely I've now wired up an actual PAF Humbucker to the control plate (obviously not installed it under the strings to see if that hummed also.....and it does hum, like a piece of stilton thats been in sunlight for 72 hours. And still that neck pup is silent and sounds amazing :-/

What the....?

[bradpdx]

Have you actually measured the ground path from the bridge plate to ground to see that is in fact zero ohms?

A visual inspection is not enough here.

[Ron S]

I have indeed Bradpdx :-) it is 0 ohms

[Tele-phone man]

what material is your bridge plate? I had hum with my Wilde L290TL when it was in a stamped steel bridge plate. When I changed back to a brass bridge, all hum disappeared. The steel distorted the magnetic field of the pickup enough to throw the humbucking balance between the coils off. A similar thing could be happening here.

[TheBenLow]

I have a similar issue in my CIJ Tele Custom which has a DiMarzio Virtual Vintage in the bridge and Duncan Vintage Stack(is that the name?) in the neck. My tech basically said those pickups are not 100% noiseless if you're playing at any sort of higher volume or with pedals and that's that. Very far from a typical true single coil though. I've gotten pretty used to it and FWIW I am still very satisfied with the sound of the pickups and guitar. Good enough will have to do.

[Zexcoil]

Originally Posted by Ron S

Hi

Has anyone ever experienced anything like this with noiseless pickups....?

I installed a set of vintage noiseless pickups in my tele this week and found that the bridge pickup still hums like a single coil. The neck pickup is deathly silent while the bridge seems to have that 60 cycle hum like my regular teles.

I had a set of Dimarzio Area T's lying around and installed them...same issue, the bridge hums too while the front pickup is silent. The bridge plate is earthed and all is wired correctly. I've shown it to a guitar tech who is as dumbfounded as I am.

Any thoughts?

Cheers

It is likely not "hum" but "buzz". Hum is magnetic interference and will change levels dramatically as you rotate your body and the pickup goes through the peaks and nulls in the offending magnetic field. Buzz is broadcast or capacatively coupled electrical noise that doesn't change much when you rotate. (You may choose to disagree with this nomenclature, but this is what I use and I think it is consistent with most of what I see in these types of discussions).

Noise-less pickups are great at cancelling hum, but all of that metal associated with the Tele bridge can make them susceptible to buzz.

Try wiring it with only one path to ground from everything in the bridge cavity. I would suggest grounding everything to the bridge plate (pickup, shielding if there is any) and then running a single wire from the bridge plate to ground in the control cavity. And if you don't have shielding in the bridge cavity, it is a good idea to combat buzz. Also, make your wiring as clean and as short as you can and employ the twisted pair wherever possible.

I can almost guarantee you the problem is not the pickups themselves. I'm still working through what is actually driving these kinds of issues, but I suspect it has something to do with the resistivity of that big hunk of bridge plate screwing with the ground potentials.

[Zexcoil]

Originally Posted by Tele-phone man

what material is your bridge plate? I had hum with my Wilde L290TL when it was in a stamped steel bridge plate. When I changed back to a brass bridge, all hum disappeared. The steel distorted the magnetic field of the pickup enough to throw the humbucking balance between the coils off. A similar thing could be happening here.

I've experienced a similar (but interestingly, opposite) response. I've also noted more problems with Tele bridge pickups with baseplates as opposed to those without.

These are the kinds of responses that lead me to believe that the root cause is related to the resistivity of these relatively large chunks of metal that need to be grounded in this situation.

[limbe]

I feel sorry for you.I have the same pickups and the bridge pickup isn´t even grounded!(I forgot to do it and it doesn´t seem to make any difference!Have you tried to wire it to the output jack with nothing else connected to the jack?Tried it in another Tele? How did the original pickup sound?I know I am shooting in the dark but I am totally stumped!
Before you buy a Les Paul try EMGs.

[Narcoleptigon]

I had a hum and signal cutting out issue with a pickup ground lead being nearly shorted near the switch lug. It was baffling, but I just grabbed the wire with both thumbs/index fingers and manipulated it at different points until I found the short.

Hi Scott. Thanks for illuminating. Not to be argumentative, but it's actually possible that ungrounded shielding in the pickup cavity can cause noise -- especially with a stacked type design. From my experience and research, I don't think there is any real value in shielding the pickup cavities, while twisting lead pairs, and shielding the control cavity is beneficial. Aluminum shielding under the pick-guard, bridge plate, and/or pickup, but not wrapped around the pickup can reduce rheostat generated noise.

[Zexcoil]

Originally Posted by Narcoleptigon

I had a hum and signal cutting out issue with a pickup ground lead being nearly shorted near the switch lug. It was baffling, but I just grabbed the wire with both thumbs/index fingers and manipulated it at different points until I found the short.

Hi Scott. Thanks for illuminating. Not to be argumentative, but it's actually possible that ungrounded shielding in the pickup cavity can cause noise -- especially with a stacked type design. From my experience and research, I don't think there is any real value in shielding the pickup cavities, while twisting lead pairs, and shielding the control cavity is beneficial. Aluminum shielding under the pick-guard, bridge plate, and/or pickup, but not wrapped around the pickup can reduce rheostat generated noise.

Of course, all shielding needs to be grounded (I think I mention that above).

If you don't perceive a tonal penalty, then shielding the entire system has benefits in terms of buzz reduction. Note that typical guitar shielding (copper, aluminum) does virtually nothing for magnetic interference at 50/60 Hz.

So for a truly quiet system you need hum cancelling + shielding + special attention to grounding and wiring techniques. In most cases I think the hum cancelling itself is good enough, but the Tele bridge in particular is where they can all come in to play.

For general info, this link has a really good treatment of shielding and grounding:

http://dsp-book.narod.ru/MISH/CH89.PDF

Note that they recommend a single point ground at audio frequencies.

[TheBenLow]

It is likely not "hum" but "buzz". Hum is magnetic interference and will change levels dramatically as you rotate your body and the pickup goes through the peaks and nulls in the offending magnetic field. Buzz is broadcast electrical noise that doesn't change much when you rotate.

Well said. That's kind of how my tech guy put it as well. At first it drove my crazy as I thought "But I thought they were NOISEless." But has worked out fine over the years and heck, even some humbuckers can be pretty noisey.

[Tele-phone man]

Originally Posted by Zexcoil

I've experienced a similar (but interestingly, opposite) response. I've also noted more problems with Tele bridge pickups with baseplates as opposed to those without.

These are the kinds of responses that lead me to believe that the root cause is related to the resistivity of these relatively large chunks of metal that need to be grounded in this situation.

Interesting response. The L290TL has a brass baseplate. I don't know about the resistivity issue, but I am sure that the change in bridge plate (NOT pickup baseplate) material had a PROFOUND effect on the performance of the pickup. As an experiment, I removed that bridge, and the pickup from the bridge, while I had the guitar plugged into an amp. The hum persisted until I actually moved the pickup out and away from the bridge. I could make the noise come and go just by moving the pickup in and out of proximity to the bridge. At this point, the bridge itself was no longer connected to ground, but the pickup was. As soon as the pickup body went into the bridge cutout, the noise returned (and the pickup became microphonic; I could easily hear any light tapping on the pickup. When the pickup was moved away from the bridge, the microphonics disappeared, too.) This proved to me without a doubt that the pickup was negatively affected in at least two respects by proximity to a large ferrous body; hum and microphonics. When I put the brass Gotoh bridge back on, neither of those issues returned.

[Zexcoil]

So...get this.

My pickup has a nickel plated steel baseplate, and has significantly less buzz with a steel bridge plate. I also have very little buzz with pickups having no baseplate.

I think the buzz may be related to the material differences between the respective plates. Possibly an impedance difference in the ground paths through the differing materials creating a ground potential difference, or coupling between the plates, or maybe a combination of both.

The ferrous plate will definitely inductively couple to the pickup, so the microphonics are likely a function only of the bridge plate material.

Originally Posted by Tele-phone man

Interesting response. The L290TL has a brass baseplate. I don't know about the resistivity issue, but I am sure that the change in bridge plate (NOT pickup baseplate) material had a PROFOUND effect on the performance of the pickup. As an experiment, I removed that bridge, and the pickup from the bridge, while I had the guitar plugged into an amp. The hum persisted until I actually moved the pickup out and away from the bridge. I could make the noise come and go just by moving the pickup in and out of proximity to the bridge. At this point, the bridge itself was no longer connected to ground, but the pickup was. As soon as the pickup body went into the bridge cutout, the noise returned (and the pickup became microphonic; I could easily hear any light tapping on the pickup. When the pickup was moved away from the bridge, the microphonics disappeared, too.) This proved to me without a doubt that the pickup was negatively affected in at least two respects by proximity to a large ferrous body; hum and microphonics. When I put the brass Gotoh bridge back on, neither of those issues returned.