Nooby and maybe grounding issue

Rudolf

Aloha boys and girls!

Ok so some know I took a recent adventure to the USA for sport and my other love. I stumbled into a shop that side to find something I've been looking for on my budget. Long story short I bought a slightly damaged Squier Telecaster Custom II and case for a very good price.

The switch on the guit was broken off, but I've already replaced this with a gold Les Paul switch as it's the same as original for 20 bucks. Our luggage got lost on the way home to SA and of course I HAD to check the guitar in because it was in a hard case or whatever. The case got virtually destroyed but the guitar is ok luckily except for one thing.

I have this very annoying crackle and humming noise on this puppy. Playing it clean is ok but anything with gain it's unuseable. I can hear a definite crackle when I touch the strings or the bridge, much louder than any of my other guitars. Not touching the strings there's a constant annoying buzz/humm. If I just normally play the thing strumming by hand I can't use the guitar at all, it crackles everytime you change a chord or strum the strings.

If I keep a finger on the jack or bridge the noise is gone completely and the guitar rocks? The noise is gone touching the tuners, pickup screws, jack, strings, bridge or the switch even.

I had to obviously open the guitar up to replace the switch, so while I was in there I had a looksy for possible things that could be causing this noise, loose ground wires and things but nothing that's obvious? The bridge ground isn't soldered onto the bridge and just clamped between the bridge and body but I doubt this is the problem?

I read alot of reviews and searched far and wide but there's no other reports of this problem on this particular guitar or what could be causing it?

I also went about checking continuity around the outside and everything seems to be good and connected to the nut on the jack. I checked with the bridge, switch, screws on pickups?

Ok final notes, I did check my equipment and everything seems good, pluggin in my Yamaha or Fender there's no problems.

Anyone got any ideas?
Thanks.
Rudolf

FenderBender

Hey Rudolf,

Check out this article on Alan's website, where he describes how he made small mods to the shielding and grounding of his (extremely quiet) Ratocaster http://www.ratcliffe.co.za/articles/hotrodstrat3.shtml

Gearhead

It would sound similarly bad if there was a very bad contact on a pot or a switch. My advice would be: replace ALL the wiring AND pots without looking for the fault. Faster and not so much more expensive in the end.

AlanRatcliffe

That's the P90 model isn't it? Cool guitar!

P90s are single-coils, and single-coils always pick up some hum - some guitars more than others. Touching the strings/metal parts basically earths you so that you help shield the guitar.

However, from what you're saying this guitar is worse than it should be. The crackling is either RF interference or a faulty earth connection somewhere. Do you get this with either pickup selected or are some switch positions quieter?

Faulty connections are best sorted out exactly like Gearhead says - replace all the wiring. You can check all your solder connections, concentrating on the earths, but that can take some time.

RF noise is helped by screening the cavities and doing things like twisting the pickup wires and output wires.

DonovanB

Why is it that one of the pins of the pots are soldered to the body of the pot? I've seen it all over but I don't know why its done. It looks so messy.

AlanRatcliffe

Shortest route to ground. I prefer taking the lugs to a solder tag under the switch, which also grounds the foil screen - the backs of the pots then connect to ground via the foil. Neater (IMO) and signal ground is not then connected via the screen, but directly to the star ground. No need to tie the backs of the pots together with another wire.

DonovanB

Alan Ratcliffe wrote Shortest route to ground. I prefer taking the lugs to a solder tag under the switch, which also grounds the foil screen - the backs of the pots then connect to ground via the foil. Neater (IMO) and signal ground is not then connected via the screen, but directly to the star ground. No need to tie the backs of the pots together with another wire.

huh? you might need to draw me a picture... oh wait, is it in your book?

Rudolf

Graeme Parfett: Thank you for the link, interesting reading. What rather bugs me about this one is that nobody else that owns this guitar is complaining about this issue? But ok, no way to determine that way what is different is there as the guys that don't have the problem aren't opening up theirs. LOL

Gearhead: Interesting idea. I'm not too scared of all the solder work and wiring, but very scared of how to actually source all the new wiring and electronics. I have no idea how to pick the right stuff, or where to find it I'm afraid. I'm by no means any good with electronics, I can solder and wire but that's as far as it goes. ☹ I'm not saying I'm not up for the challenge, anyday, but I will need SO much help. Hehe

Alan: Yes this is the one with the Duncan P90's. And yes, very cool and pretty guitar! Haha. This is the one: http://www.squierguitars.com/products/index.php?partno=0327602506

This guitar is definitely much worse than it should be, touching strings or something on my Fender or Yamaha indeed you can hear a slight click through the amp but this one sounds like lightening just struck. It's a loud pop and crackle every time. The noise overpoweres the sound from the strings completely. If I try to play it normally just changing chords and strumming along it's a constant snap, crackle and pop probably 70% of what's coming out of the amp over the sound of the strings. The noise is there in all three switch positions definitely, only thing that reduces it is turning down either tone knobs completely.

I'm up for re-wiring this thing, but like I said sourcing the right stuff for the job is my biggest worry. Apart from that I'll need a way to figure out which wire goes where, if this guitar is wrong now to begin with I can't just mirror the setup with better soldering and such? One thing that definitely caught my attention is the wiring used in the guitar, it's not your normal setup where there is a live and seperate ground wire to everything. The wires is a single wire with both live and earths in one, kinda like a television cable, the ground runs on the outside and live shielded in a smaller wire inside? Does that make sense? I don't know if this is possible the route of all evil, maybe somewhere along the line one of the grounds went astray and is touching something it shouldn't be?

AlanRatcliffe

DonovanB wrote huh? you might need to draw me a picture...

Don't worry about it - the stock back of the pot method works fine.

Mine is an extension of star grounding (which isn't really neccessary in a guitar). I like it because it's a bit neater and means I don't have to use a high wattage soldering iron on the backs of the pots. I could take a picture, but that would probably confuse you more - my guitars tend to have a few more bits connected than stock.

Rudolf wrote The noise overpoweres the sound from the strings completely. If I try to play it normally just changing chords and strumming along it's a constant snap, crackle and pop probably 70% of what's coming out of the amp over the sound of the strings. The noise is there in all three switch positions definitely, only thing that reduces it is turning down either tone knobs completely.

OK, that's definitely bad wiring - a dry joint or a faulty wire between the switch and the output jack (the only areas that affect all switch positions on a four control guitar). I'd guess it's the wire - it's likely that in replacing the switch you overheated the shield and melted the insulation around the conductor (happens easily with Asian made wire). Try shorten it a bit and resolder (or if there isn't enough slack replace the whole wire). It could also be a solder joint on the output of the switch or on the output jack, but my money's on a melted wire at the switch.

Rudolf

Hi Alan,

Hmm I can definitely go on the whole insulation melting thing happening with these wires, was the first thing that caught my attention when I opened the guitar up. I just couldn't see how this could be the best way to do the wiring in a guitar like this, the ground wires are dreadfully thin and fray everywhere. The insulation between live and ground is also a bit on the dismal side. I think you are onto something.

Is there any way to hunt down the problem wire with a multimeter or would one have to de-solder everthing in order to do that? I can easily rip out the wire from the switch to the jack and replace that yes, should be easy. No way to double check everything else while I got this baby opened up?

Heath

sound to me more like you got the hot and the ground wires swaped around from the jack , making your ground hot i would check the wiring from the jack to the switch and make sure they the right way round.

AlanRatcliffe

Tailon. wrote sound to me more like you got the hot and the ground wires swaped around from the jack , making your ground hot i would check the wiring from the jack to the switch and make sure they the right way round.

Also thought of that (it's a very common mistake), but that would make the metal parts live and touching them would make the hum worse, not better.

Rudolf wrote Is there any way to hunt down the problem wire with a multimeter or would one have to de-solder everthing in order to do that?

You're looking for a short and while you can tell there is a short with a meter, it's difficult to say where.

I can easily rip out the wire from the switch to the jack and replace that yes, should be easy. No way to double check everything else while I got this baby opened up?

Ocular inspection (look at it!). Usually, if it's from overheating, you can see the shield wire melted into the conductor's insulator as it happens right at the end. When in doubt, clip off the last centimetre or two and redo. Otherwise just replace the wire - I'm pretty sure it's that. You do need shielded cable BTW, as it's a relatively long length and they don't shield the complete pickguard or cavity in those guitars.

Rudolf

I'll rip it open tonight, get some pics while I'm at it. It's fairly easy to see what goes where on this one as all the wires are coloured nicely going to the different bits.

I'm wondering about the ground hookup at the switch. Everything hooks up at the switch, in other words there's three wires coming in and all three those wires's grounds are linked up to the ground on the switch, their all twisted together and then dropped into the switch, very possible more heat went into that mix than what should have. I can see how with the ground surrounding the live, getting the ground out and twisting it to a point so it can be soldered on somewhere might put some strain on the ground frays helping them when heated to cut into the insulation of the live.

Alan: Correct on everything not being shielded, only the cavities have little patches of foil on the pickguard and yes the cavities themselves definitely aren't shielded. I think this puppy is begging for a good shielding job. I would have loved to just rewire the entire thing with proper wires and doing the shielding job proper while I'm at it. Too many options right now, too little knowledge. LOL. Time to google I guess.

Rudolf

Hi friends,

I opened the guitar up again to have a looksy, I can't say I'm happy with the wiring in it at all. The whole idea of the ground wires surrounding the live wires is just no good, the grounds in these things are really microscopic and fray out everywhere. I'm not 200% sure but I think I may have found the problem. I couldn't find anything wrong as far as insulation being melted is concerned anywhere and all the grounds really look good? I also ran the tester through the whole thing everywhere to look for any sort of ground leaking into a live but nothing, admittingly I am not so sure one would actualy see such a problem through the tester but it does seem sensitive enough?

Anyways the wire running to the jack from the switch has a little damage on it, so much so that there is a hint of grounding wire showing through the chaff (sp?)? It seems it might have gotten stuck between the pickup and body or something and got damaged. I don't understand how this could be the root of the problem though? Doesn't make sense since it's ground that's exposed?

Anyways, I don't have any tools or anything around as all my stuff is still stuck in the crates along with my helicopters on their way back from the USA. As luck would have it along with my insulation tape also. I wanted to insulate the damaged spot just to check if this maybe helps the problem. Only thing I could find to maybe use was a piece of sign writing vinyl. Hehehe. Well put it on anyways and slapped it all back together. I realise the vinyl is not at all intended for the job but here's the kicker. I believe this actually helped?!?!

It still hums alot if you don't touch the strings but the crackling seems to be a whole pile less, so much so that the guitar is now playable even with heavy gain and distortion settings. The problem is far from gone but I honestly believe it's a whole lot less.

I guess now to decide, do I go shop for a proper set of wires to hook up the switch to the jack? Or do I go shop for a whole wiring kit of some sort to just re-wire the entire guitar? I really want to try and reduce the noise coming from the guitar in general if you don't touch the strings, without forking out an arm and a leg right now. But should I rather save and just do it all at once, later.

Anyways here we go, the picture of the damaged spot on the wire from the switch to the jack:

Some more pics of the guts:

Gearhead

Rudolf wrote The whole idea of the ground wires surrounding the live wires is just no good, the grounds in these things are really microscopic and fray out everywhere.

This sounds exactly like it should be (and on the photo's it seems to be as well): the ground is completely surrounding the hot. The poorest version of these 'shielded' cables just has metal foil (do not use), the intermediate kind has a number of thin wires spiralled around the core (okay-ish) and the expensive ones have many thin wires braided across the surface.
http://za.rs-online.com/web/search/searchBrowseAction.html?method=getProduct&R=6264610#header
is the general idea. You strip back the earth a couple of mm, de-braid it, wrap it together and put solder in. I sometimes put some heat shrink tubing around it to prevent accidental contact with the hot lead. You solder both the hot and the earth on both ends of the lead.

Rudolf wrote I'll need a way to figure out which wire goes where, if this guitar is wrong now to begin with I can't just mirror the setup with better soldering and such?

It's like building rc airplanes ? you read up, you try out and before you know it you can do it. There's so many resources for guitar wiring it's too much to read. Easiest imho is to have a look on the Duncan website, they do list your guitar config, you can download a nice picture-for-dummies that'll sort you right out.

AlanRatcliffe

Rudolf wrote The whole idea of the ground wires surrounding the live wires is just no good, the grounds in these things are really microscopic and fray out everywhere.

Nothing wrong with it done properly with decent quality wire - look at old cloth covered stuff used in Les Pauls or DiMarzio shielded wire with Teflon insulation (which doesn't melt easily). For that matter consider guitar cables... It's when the cheap wire is used that you end up with problems. I almost always use shielded cable as a matter of course.

Anyways the wire running to the jack from the switch has a little damage on it, so much so that there is a hint of grounding wire showing through the chaff (sp?)? It seems it might have gotten stuck between the pickup and body or something and got damaged. I don't understand how this could be the root of the problem though? Doesn't make sense since it's ground that's exposed?

That's just on the surface - often a core insulator will be similarly damaged (sometimes not even showing up on the outside) and then there is a very real chance that the shielding wire is touching the core wires. Or even just close enough that it causes a discharge that causes crackling. The improvement might not be because of the vinyl insulation you added, but from moving the wire around.

One thing that intrigues me - that grey paint in the control cavity. That's graphite screening paint (badly applied, but better than nothing), but there doesn't seem to be any connection to it (or not that I can see in your pics) - you would usually see an earth wire and a screw driven through the paint into the body and with the other end connected to the back of one of the pots at the same place as the earth wire for the bridge. Now I think of it, where is the bridge earth wire? You need both those wires to cut down on noise.

I guess now to decide, do I go shop for a proper set of wires to hook up the switch to the jack? Or do I go shop for a whole wiring kit of some sort to just re-wire the entire guitar? I really want to try and reduce the noise coming from the guitar in general if you don't touch the strings, without forking out an arm and a leg right now. But should I rather save and just do it all at once, later.

I usually go all out and replace everything, but that's more as a labor saving thing in the long run. In your position now, maybe just replace the wire if it is faulty, but know that you are probably going to have to go back in there in a few months to fix something else.

BTW, here's the service manual including the wiring:
http://www.squierguitars.com/pdf/current/Tele/Vintage%20Modified%20Tele%20Custom%20II-%20Service.pdf

Rudolf

Hi guys,

Ok if this stuff is the shizzle for the experts then I will definitely not argue. Hehe. So we learn huh? More I think about it I guess these wires as is will keep unwanted noise away from the live which it surrounds. Makes sense also now.

Gearhead: Thanks for the motivation. LOL. I aint skeered of many challenges but I guess right now because I'm not at all knowledgeable on guitars it kinda rattles me. I'm looking at the electronics differently everytime though I open one of these, looking at wiring diagrams the past few days I'm feeling a little braver everytime. I can't say for sure if the wires in this guitar is definitely braided properly, their so darn small? Should these wires be so microscopic or are the proper wires a little more beefy?

Alan: Gotcha on the live also possible being damaged. I wouldn't be too surprised. I couldn't make sense of the whole vinyl thing making a difference, but now that you mention it maybe just moving it around changed the amount of leakage.

I checked the gray stuff in the cavities for conductive properties and it's definitely there but very very poor. If I run the tester on a small distence it conducts but with ALOT of resistence, long distances (Say 10cm) and there's nothing? Is this paint any good to use? Should I maybe get some more and do a proper job of applying it? Or would it simply be better to get the foil stuff and filly the cavities with that?

The bridge is grounded via a tiny black wire running to the jack. The other end of the wire is simply clinched between the body and the bridge, no solder, however it checks out good on the tester? The graphite paint (If it really is the stuff) however doesn't look to be grounded though no.

I think I need to find proper wiring for this thing and just do the job proper and get it over with. I suppose I don't need to replace all the electronics right now, maybe just redo all the wiring with proper stuff? I'm weary of replacing pots and things just yet, unless you guys reckon it's probably worth it? I'll need alot of guidance though. Hahaha

Thanks for the help so far, much appreciated.

AlanRatcliffe

The paint won't do anything if it's not connected to earth. Applied that badly, it won't do much if you connect it either (you usually apply a coat or two, nice and thickly. Still, it's not the best conductor, even properly applied (you also get copper and silver based paints used for marine wireless that are great, but horribly expensive), so first prize for me is the copper tape. The 2" tape with the conductive glue from Stewmac is great for cavities, while you can get sheets big enough for complete pickguards (the glue is not conductive, but you don't need it) from Guitar Nucleus.

I have to be honest, If I have to work on the wiring of an inexpensive guitar, I'll replace everything from pots and switches through wires to the output jack. All with good quality stuff. Then I know that I can leave it and it'll be good for the next 10 - 15 years. I find that if I just replace the faulty bit, I'll be going in again in a few months to replace the next faulty thing, until after a year to 18 months, I've replaced everything anyway, but the wiring is not as neat because it's been worked on multiple times. However, I do understand the economics of doing it bit by bit, so would say do what you think will suit you best.

The loose wire under the bridge is fine - the screws clamp it between the body and the bridge so it works well. You'll find exactly the same system used on hardtail Custom Shop Strats.

More on wires:
The cheaper screened cable often uses what is called a lap screen, where the shielding wire is simply wrapped around the insulated conductor wire and then insulated on the outside. Next up are the braided shield (like the wire Gibson uses) which give better coverage, but are not insulated on the outside, so prone to shorting out on live stuff. Some of the more modern braided shield wire is also insulated and some are a looser braid to make them a bit more flexible at the cost of a little coverage. The best coverage is the foil screen, with a single bare wire for soldering. The foil screen is not very flexible, but I find that OK for wiring inside a guitar, where it doesn't get moved around much. All of these wires come in different qualities, with different metals used for the conductors and different insulators - it can get quite complicated. Mostly stick with the stuff you get from the better guitar supply shops (Mojo, Acme, RS) and you can't go wrong.

I should also mention that unscreened twisted pair wire works well in a guitar too, but is not commonly found (I don't know why). That's when the two wires are simply twisted together.

FenderBender

+1 Alan

UTP or unshielded twisted pair cable works wonders for signal cables as noise is very effectively cancelled out when the current travels down and then back up the twisted pair. The effect is similar to a humbucker pickup. It is also used effectively as a means to transfer digital data noiselessly in the form of everyday ethernet cables and far easier to work with and solder than co-axial screened cable ?

Rudolf

Thanks for the info guys. I'm checking the online shops to see what the deal is. Pots and wires don't seem too expnsive, only thing that now really hounds me is the fact that I don't really want to import. I'm going to read up as much as possible tonight and check out the shop tomorrow to see if they stock anything worth getting. I doubt they'll have everything but lets see what happens.

If I can just find a shop that stocks everything from the copper tape to pots to wire. Hehe. I'll keep you posted on my options then check back.