Horrible (grounding?) buzz on HSS with coil tap

[madman]

Hello, guys!

I'm putting new pickups into a friend's guitar and he wanted - an HSS, master volume, master tone, humbucker coil split via an SPDT switch.
The pickups are Lace Sensor Silvers and the hum is Fralin's Unbucker, made for coil tapping.
The guitar is a 20+ year old Yamaha Pacifica.
The pickups used to be in my guitar, with push-pull coil splitting, neck adding to the bridge etc. and they were dead quiet, worked great.

Below is the schematic.
He wanted it ASAP and it was a Saturday, I couldn't get my hands on a 250K linear pot for Tone, so I just used the same 500K log as for the Volume.

I put in two 470K resistors so the neck and middle single coils would "see" a 250K pot and the humbucker simply gets the full 500K.
An SPDT switch is just a plain old toggle switch to send the coil tap to ground.
Everything is freshly soldered, checked for errors and connections/cold joints, the pickguard has foil on it, so pot casings are all grounded. (those things under the pots are simple solder lugs, so I don't use the casings)

So far, so good.
Here's where crap hits the fan.

I plug in the guitar - everything works.
All the pickups and the positions work and give sound, coil tap works, fingers-on-strings "grounding" works, all the controls do as they should (tone on full sounds GREAT).
But here's a HORRIBLE ungodly buzz, that raspy, intense, almost farting noise, sounds really lower frequency.
It's not hum, not like background noise that softly hums through the amps or like a TV, it's the other, agressive kind (grounding noise?) :/

It's slightly reduced when I turn the TONE down, it muffles it a bit - when Tone is full on, the buzz is full on.
It's the same on every pickup, every position.
Reacts to Volume - I turn down the Volume, buzz goes away, so it's not on all the time.

The switch also has a tiny bit of woble in the position when it splits the humbucker, but it doesn't affect the problem overall for better or worse.

I just don't get it.
I tried it out on a Fender Mustang in one room on one outlet, then tried it out on my Dumble clone in another room on another outlet - brand new shielded power cable, all equipment worked perfectly with another guitar a week ago.

Could you kindly provide any advice?

THANK YOU!

[newey]

madman-

You've already confirmed those things I would have told you to do. I don't really have any idea why your having the issue.

Probably a stupid suggestion, but have you checked that the wires to the jack aren't swapped?

[madman]

You know what, that's not a stupid question as those kinds of stupid mistakes do happen
Thanks for a reminder, I really wanted to have someone see the schematic and point out if there's a nasty error in it.

[madman]

Rechecked the wires - output jack connected properly.
Rechecked solder joints.
The pickups' casings are grounded, so are all the pot casings.

Here's the link to a recording - BUZZ AUDIO

WTF :/

[frets]

Hi Madman,

This advice is going to sound very non-scientific but it’s a true story. I upgraded a Pacifica for a customer and it had the same problem. A horrible buzz that I could not for the like of me figure out. It seemed to have something to do with the shiny stuff they use for EMF. I swear as soon as I covered that stuff with copper, the buzz was gone.

I’d try taping over that shiny material to see if it eliminates it.

I know guys, it makes no sense but I swear on Yamaha Pacifica’s their shiny material intended for EMF cause all sorts of problems when you put a new harness in.

[madman]

Hey Frets!

At this point I'm willing to cover it with snake skins if I have to.

Just reverted it back to an original Pacifica schematic - I don't think things could be much simpler than THIS.
The buzz goes down a bit when Volume is fully open, but not that much.

[b4nj0]

I just keep on and on looking at how the tone pot is configured. Seems to me that when the capacitor is out of circuit, the whole 500K tone potentiometer is then in parallel with the the volume pot? Also, since they're both log pots, your chosen "ground" ends are at opposite ends of the tapers?

You're looking for something that is independent of the switch and pickup wiring which clearly works fine, hence the earlier obvious flipped output socket comment, but what about the tone pot which is also independent of the switch and therefore common to all pickup selections? Apart from (obviously) no more tone control, what happens if you just temporarily disconnect one end of that inter pot wire?

There are many ways to configure a tone pot and capacitor- so-called 50's and modern spring to mind, but I don't recognise either of those in your current topology. I have a Pacifica 904 and I'm tempted to dig out its wiring diagram now because maybe that's how Yamaha do things, and I'm just bring dumb amongst my betters here?

As noted, at present, it looks like the capacitor is theoretically out of circuit at zero treble cut with the aforementioned effect of the full pot track being parallel with the volume pot, but as the tone is rolled off, the capacitor is in parallel with the tone pot track it is straddling, and in turn that varying tuned RC circuit is in series with the rest of the tone pot track? Sure it varies the capacitance, but not like a conventional potential divider and it has me scratching my head. If nothing else I might learn something here!

I would lift the capacitor from the tone pot "ground" tag and connect it to the input tag on the volume pot. Remove the inter pot wire from the volume pot and with it "ground" the opposite tag on the tone pot.

I would not rely upon any foil shield for "grounding". I suspect that frets was thinking along similar lines?

And it's pretty late here, so I apologise to the group if'n I'm spouting twaddle ... Things might look different in the morning ... ;<D

e&oe ...

[madman]

Hmmm, I think I see what you're saying.

OK, here's what I often see in other schematics the Tone is wired like (left) and here's what I think you're suggesting (right), b4nj0?
Please pretend that I've also connected the pots with real wires and am not relying on the foil for grounding.

Would this be right?
Thank you very much for clearing some things up!

[reTrEaD]

Hi madman

All three ways you've shown the tone control will work equally well. The important thing is that you use the CCW lug and the wiper of the tone pot. Whether the series connections begin with the tone pot (either CCW lug or wiper) being connected to the CW of the volume, or begin with the cap being connected to the CW lug of the volume ... makes absolutely no difference.

Aug 2, 2021 18:48:12 GMT -5 madman said:

Please pretend that I've also connected the pots with real wires and am not relying on the foil for grounding.

If that means the end of the tone cap shown being locally grounded at the tone pot also has a wire going to the same ground at the volume pot where you have the wire from the spring claw and the wire going to the sleeve of the output jack, all should be well with that part of your diagram.

[newey]

If the diagram you used is OK- and it looks to be so- and you've tried all the testing etc that you have done,maybe it's time to consider the possibility of a faulty component. Assuming these are new parts, it's unlikely, but at this point you (and we) are scratching our collective heads. So, maybe swap out the pots, see if that makes a difference.

[madman]

Aug 2, 2021 21:21:07 GMT -5 reTrEaD said:

Hi madman

If that means the end of the tone cap shown being locally grounded at the tone pot also has a wire going to the same ground at the volume pot where you have the wire from the spring claw and the wire going to the sleeve of the output jack, all should be well with that part of your diagram.

Yes, I soldered a wire from one pot ground lug to another pot's ground lug, they're physically connected with a wire.
Nothing changed

[madman]

This is turning into a nightmare.

This morning I disconnected everything - the pots check out fine at 500K, the pickups are as rated, the switch switches.

I plugged in my old HSS Strat to both amps in both rooms - buzz, on single coils and the humbucker.
The only way to get rid of it is to turn the Tone control all the way down.

I borrowed a friend's HSS Strat, tried it on both amps in both rooms - buzz on all pickups.
Tone controll all the way down also gets rid of the buzz, but kills the treble, too, as usual.

I turned on both amps WITHOUT ANY GUITARS plugged in and turned the volume slightly up - buzz.
So, I suspected the power cable.
I used a friend's power cable and also the one I use for my computer - buzz on all amps, with or without the guitars plugged in.
Same raspy sound in all combinations.

I suspected the grounding in my house, YET - a month ago I was changing an output jack on a friend's Ibanez Les Paul copy from 1975. and it was dead quiet.
I have no idea how to untagle this mess.

I can accept single coils are what they are, but the buzz is persistent even on three different humbuckers AND these Lace Sensors were 100% proven to be dead quiet as I used them for 7 years in my house and on other venues.

The good thing is that the problem may not be the guitar I'm wiring, at all.
Don't know how to explain that one guitar that had no buzz.

I'm going to connect everything back as it was, assemle the guitar and simply go try at someone else's house.
Thank you for your patience, I'll get back to you so we all know we're not crazy.

P.S.
Oh yeah, when I short the Volume Out to ground - silence

[col]

Maybe try adding one component at a time?

[b4nj0]

From your last post where you stated that just the amps alone were affected, and the fact both are affected, it's safe assume that you can exclude the guitar's wiring.

Do you have any fluorescent lamps that may have a dodgy start up capacitor? Do you have any of those dreaded touch control lamps? Have you (or a reasonably close neighbour) installed anything new recently? Roof solar panels with charge controllers? Even solar charged garden lights, anything. Any chargers that incorporate switch mode PSUs, particularly if left plugged in but with no load. Anything charger-like with boost/buck circuitry? You need to cast your net wider with an open mind and remote diagnosis is just like throwing darts blindfolded.

Try isolating the lighting at the consumer unit, that will narrow down things, at least in your own house!

Welcome to EMI / EMC smog! I've spent a tidy sum on ferrite toroids here. Although my requirements are a little different, many solutions are the same in nature. col's "one at a time' advice is sound, but apply it generally and not just to guitars an amps.

e&oe ...

[unreg]

Aug 2, 2021 21:21:07 GMT -5 reTrEaD said:

Hi madman

All three ways you've shown the tone control will work equally well. The important thing is that you use the CCW lug and the wiper of the tone pot. Whether the series connections begin with the tone pot (either CCW lug or wiper) being connected to the CW of the volume, or begin with the cap being connected to the CW lug of the volume ... makes absolutely no difference.

Note: CW and CCW lugs explained here: guitarnuts2.proboards.com/thread/6612/potentiometer-orientation

[reTrEaD]

Aug 3, 2021 7:34:50 GMT -5 madman said:

I suspected the grounding in my house, YET - a month ago I was changing an output jack on a friend's Ibanez Les Paul copy from 1975. and it was dead quiet.
I have no idea how to untagle this mess.

Aug 3, 2021 7:34:50 GMT -5 madman said:

Don't know how to explain that one guitar that had no buzz.

The explanation is: That was then, this is now. Something has changed in your local environment, even if you aren't aware of what or how that has changed.

Could be a failure in the earth connection at the mains. Or perhaps something has gone wrong in a fluorescent light fixture as b4nj0 suggested. The spiky/raspy noise that seems to be a harmonic of 50Hz or 100Hz would make me suspicious of something like that.

Aug 3, 2021 7:34:50 GMT -5 madman said:

I'm going to connect everything back as it was, assemle the guitar and simply go try at someone else's house.

Excellent plan. If YOUR guitar and YOUR cable and YOUR amp exhibit normal levels of background hum in one or more other environments, you can be certain this problem is based in your home.

[madman]

Interesting observation - when I stand in front of an amp, with the guitar facing it, the buzz goes down drastically.
If I turn the guitar in any way away from the amp, flip it parallel to the floor or sideways - the buzz comes back fully.
Also, the amp exhibits NO buzz or hum without a guitar cable plugged in, as soon as I plug in ANY cable of ANY length, it picks up buzz like an antenna - and it's a quality US made cable I used for everything.

To me, it seems like every time the guitar's electronics are directly exposed to the amp (as in line of sight) - it buzzes.
That would lead me to believe that a lack of shielding in the guitar's electronics cavity may be responsible, as it's just a tiny bit of aluminum foil under the pots/switch area.
Maybe that's what frets was talking about?

Anyway, he's coming to pick it up tomorrow and he'll try it out at his place - he says the guitar used to buzz till he found an outlet that was quiet.
I live in a typical middle-class suburb in Croatia, there's not a lot of fluorescent stuff here, nor solars - I have a small LED desk light three rooms over, turned off.
If someone installed some LEDs or something in their house I can't really tell, we're four houses in a row, wall-to-wall, and it's possible something from someone's bedroom interferes with my outlets with just a wall in between.

This is the final schematic and we'll see what happens when he gets the guitar home.
I omitted one of the resistors, so positions 2 and 4 wouldn't "see" both at the same time.

[unreg]

Aug 3, 2021 9:15:12 GMT -5 b4nj0 said:

Have you (or a reasonably close neighbour) installed anything new recently? Roof solar panels with charge controllers? Even solar charged garden lights, anything. Any chargers that incorporate switch mode PSUs, particularly if left plugged in but with no load. Anything charger-like with boost/buck circuitry? You need to cast your net wider with an open mind and remote diagnosis is just like throwing darts blindfolded…

Aug 3, 2021 13:16:02 GMT -5 madman said:

If someone installed some LEDs or something in their house I can't really tell, we're four houses in a row, wall-to-wall, and it's possible something from someone's bedroom interferes with my outlets with just a wall in between.

Maybe phone your neighbors and inquire about their electricity/lighting use?


EDIT: Going out on a limb to suggest that simple LEDs are not the problem.

FINAL-EDIT: I suffered with noise too; clear acrylic nail polish helped reduce the noise a bit:
guitarnuts2.proboards.com/thread/9294/clear-acrylic-nail-polish-unreg?page=1

[madman]

Aug 3, 2021 15:29:17 GMT -5 unreg said:

Aug 3, 2021 13:16:02 GMT -5 madman said:

Maybe phone your neighbors and inquire about their electricity/lighting use?

I would, but everybody around my house is 200 miles away on vacation I could break in..
Just went outside with a flashlight - nothing new in the front/back garden, no motorized garage doors, pot growing installations...
I also tried the ground floor of the house, front to back, hauling the smaller amp around - every damn spot is the same.

I'm really starting to think shielding the cavity might solve the problems as my guitar has no pickguard and the back cavity is all wrapped in thick copper foil, including the lid, never had problems with noise, even with regular singles.

FINAL-EDIT: I suffered with noise too; clear acrylic nail polish helped reduce the noise a bit:
guitarnuts2.proboards.com/thread/9294/clear-acrylic-nail-polish-unreg?page=1

How does nail polish help with noise?

[unreg]

Aug 3, 2021 17:00:17 GMT -5 madman said:

How does nail polish help with noise?

frets indirectly introduced me to nail polish use; I believe I quoted part of another thread at the top of that linked thread. In my guitar, the ends of the wires were bare. Like I’d strip a 4th to an 8th of an inch and solder only about a 16th inch of that end. The nail polish covers that bare non-soldered wire-end sections. In my thread I linked, frets explains that nail polish should only be used after the wiring is complete bc it drys hard.

I believe she also gives other wire covering recommendations there too.

Oh, and a big noise problem for me was my old amp.


tl;dr: It’s a way of shielding small parts of bare wire ends. Less entrances for sound interference is great! 👍


EDIT: If you decide to use nail polish, spend the time to find CLEAR ACRYLIC nail polish bc that’s what frets recommended and it works wonderfully. 😊
Kind-warning: There are tons of nail polish types.

[b4nj0]

Nail polish preventing unwanted noise from "getting in"? I'd have to get my head around that one. Sure it would serve to protect against corrosion, and we used to do just that with so-called "blue varnish" on aircraft wiring "grounding points", but unless it is heavily laden with conductive metal flakes (some indeed do appear to be!) or like guitar cavity screening paint, I find it difficult to visualise any noise amelioration effect whatsoever.

As already hinted at, a check at a friend's house (not just next door ...) should exclude the house wiring. After that it's down to tracking down the offending item(s). The cure may be a whole other enchilada, and might involve convincing someone with no problem of their own to play ball.

e&oe ...

[unreg]

Aug 4, 2021 4:33:13 GMT -5 b4nj0 said:

Nail polish preventing unwanted noise from "getting in"? I'd have to get my head around that one. Sure it would serve to protect against corrosion, and we used to do just that with so-called "blue varnish" on aircraft wiring "grounding points", but unless it is heavily laden with conductive metal flakes (some indeed do appear to be!) or like guitar cavity screening paint, I find it difficult to visualise any noise amelioration effect whatsoever.

That acrylic nail polish shields the wire it covers. <I’m not sure how it works, but frets saying so and my experience proves, to me at least, that it does work. 🙂


EDIT: selfstudy365.com/qa/what-material-is-chosen-for-covering-electrical-wires-a-51503 says:

Bakelite is a form of thermosetting plastic which is used for making plastic covers of electrical wires and for making handles of utensils.

Bakelite is a poor conductor of heat and electricity. Therefore it can be used for making electrical switches, handles of various utensils, etc thus protecting us from fire and electrical hazards.

And you b4nj0 say that the covering needs to be metallic to prevent noise. I somewhat agree, obviously guitar shielding IS metallic; but, in an environment where lots of noisy frequencies are present, material in the way of noisy frequencies does lessen that frequency.

Like, wifi becomes weaker traveling through non-metallic walls, and yes, if a dryer is also in the way the wifi completely perishes.

madman’s guitar doesn’t even have a cavity cover, so that clear acrylic nail polish would help, I think. Note: At least, I hope it would help; it helped my guitar that has a foil-covered-on-the-inside cavity cover.


FINAL-EDIT: After typing all of that I researched more… Saley Hanson’s Big Shiny Top Coat is made of an Acrylic Polymer Complex; and www.sciencedirect.com/topics/chemistry/acrylic-polymer says:

Acrylics have exceptional resistance to UV light, heat, ozone, chemicals, water, stiffening on ageing, and dry-cleaning solvents

. So, it must be just the added material that makes a difference. Heat-shrink tubes are applied to bare wire to help reduce the noisy frequency too right?

Painting on clear acrylic nail polish is tons easier, after a wire has been connected, than using a tube covering.

[b4nj0]

Well I'm not going to dig my heels in unreg because I don't have the benefit of your hands-on direct experience in this, nor frets for that matter, so I'm just another typical internet commenter destined to obscurity, but dwelling on the reference to Bakelite, I reckon there's at least some chance someone is thinking of "insulating" as opposed to "shielding" here? Hey- help a guy out here!

I suspect ChrisK would murmur "Feldegarb" under his breath?

e&oe ...

[newey]

Aug 4, 2021 14:16:53 GMT -5 unreg said:

So, it must be just the added material that makes a difference. Heat-shrink tubes are applied to bare wire to help reduce the noisy frequency too right?

Never heard that. Heat shrink tubing is used for insulation and to add durability/abrasion resistance, and also to prevent environmental contamination (dust, dirt, etc) from getting into wiring.

If the material used to make it were conductive, it would make for a lousy insulator. But if the material is not conductive, then it can't shield against noise- a Faraday cage, the basis for the whole idea of (passive) electrical shielding, needs conductive material to work (and the material needs to be grounded, as well).

Nail polish used as an insulator, okay, but it's not reducing any noise. The coating on the wire used for winding pickups is an acrylic coating not much different from nail polish.

(and I'm no expert on makeup or nail polish, but I'm pretty sure that there is no actual metal in the metallic polishes. I suspect it's little bits of Mylar plastic or some such. Or maybe fish scales- that's what they use in lipstick to make it "shimmer". Actual metal would be expensive and there's too many people with metal allergies.).

[col]

Aug 4, 2021 14:16:53 GMT -5 unreg said:

Like, wifi becomes weaker traveling through non-metallic walls, and yes, if a dryer is also in the way the wifi completely perishes.

My thin-knowledge take on this:

Walls and dryers are relative thick and dense (and dryers make use of sheets of metal). Wifi operates at extremely high frequencies (in the gigahertz range). These two things do result in wifi signals quickly deteriorating indoors (or even outdoors). On the other hand, a very thin layer of nail polish, and the low frequencies of radio noise which both make it into the guitar and are audible (<22,000Hz), will not be obstructed by the presence of a think layer of nail polish. My guess is that any possible attenuation of the signal by the polish would only not be unnoticeable, but too small to be even measurable.

[b4nj0]

They are not audio waves, they're electro magnetic waves that become rectified and then manifest as audio waves, sawtooth going by your description!

Occasionally you might encounter the "rusty bolt" effect where the corrosion between two dissimilar metals acts like a depletion layer. This resembles a crude diode which then rectifies electro magnetic waves and is subsequently amplified by the amp to an audio level, but on the balance of probabilities that's not the case here. This is more like direct pick up by the amp wiring, but both amps? Hmm. As I said earlier- remote diagnosis is a can of worms.

Here's a thought; try a portable transistor radio on AM (remember them!) with the volume set high and tuned between stations. This will have an internal directional ferrite rod antenna. Walk around the room and house altering it's position this way and that and see whether you can detect the noise, and if you can subsequently rotating it to null it out. The null(s) will be off the ends of the ferrite rod. If you're lucky you might be able to trace the source directly, or even crudely triangulate it. Just an idea to try.

e&oe ...

[col]

b4nj0, are you referencing me? Assuming you are (but I am far from certain about this):

Of course I realise they are not 'audio waves'. Rather, they are electromagnetic waves at frequencies which might be audible to the human ear when picked up the pickups. We cannot hear wifi signals collected by pickups of course, or anything above about 22KHz. I expect there are modulated frequencies well below the gigahertz range within wifi signals, but I'm going to guess these are still way higher than what can be detected by the human ear.

Edited for clarity.

[b4nj0]

Hey col, my bad (as they say) I'm not up to speed with protocols even now!

No one can hear electro magnetic waves until they are mixed down to a frequency (either directly or through one or more intermediate frequencies) that can then be passed through a transducer (such as a loudspeaker) that creates the sound pressure waves which our ears can respond to as audio.



e&oe ...