Bad pot?

[curtisa]

I'm starting to wonder if it might be the switch. You can hear the position changes through the amp as you move the switch particularly at each end of the throw.

I'd expect most switches to make a bit of electrical (*crackle*) and mechanical noise (*thunk*, picked up by the pups) as it is moved.

On the other hand, I fought that problem with my last guitar which has humbuckers. I'm convinced that my house wiring is the culprit in that case, and running the amp through a power conditioner took care of that.....and it is not taking care of it in this set-up. These are single coils though........but so are my P-90s, and they do not have this buzz.

I note that the leads from the Klein pickups are not shielded and are just two plain wires. Are the leads on your P90s shielded cables or separate wires?

What if I had the leads from the pups reversed? I doubt that is the issue since the bridge pup does not really seem to be affected.

Worth checking. The photo on the Klein website makes it look like the black wires from each pickup are meant to be soldered to ground, rather than white/yellow. Does the neck/middle combo have that typical Stratty "quack" (think Hendrix "Little Wing" or Dire Straits "Sultans of Swing"). An incorrectly phased neck pickup relative to the middle will sound quite odd when combined together and lose it's hum cancelling ability too.

[ScottR]

The p-90s are shielded. Built by RAD by the way. The Kleins do have the black wires soldered to ground. They are actually really nice sounding pups. Full of bluesy tone and will quack in every position. I will still isolate the pups and test this weekend, but I'm now starting to think it may just be strat pups combined with my dirty current. I was told today that strats commonly buzz on the neck and middle pups.

I'll get a chance to test at a different location in the next couple of weeks.

SR

[Workingman]

More out of the box, but did you ground your conductive paint?

Also is anything in the live part of the ciruit touching the grounding paint?

[curtisa]

The p-90s are shielded.

I'm willing to bet that's the difference. The neck pickup wires are longer and unshielded, and will pick up more noise than the bridge and middle pups, which have less exposed lead length. The route that the wires take may have an effect on the degree of noise pickup too.

If this is finally the cause of your noise problems I can think of a few things you can do (in order of effectiveness):

1. Desolder the existing pickup leads and throw them away. Replace with a piece of shielded hookup wire - shield conductor replaces black wire, centre conductor replaces white wire.

2. Tightly twist the existing black/white wires from the neck pickup. You'll probably have to remove the pickup from the guitar to do it effectively. You may want to consider doing this to the other two pickups as well.

3. Live with a little more noise from one pickup

[ScottR]

Curtisa, I think you are right. I'm playing right now and the buzz has gotten quite a bit quieter, which happens in my house. No idea why, but sometimes the amps are quiet as a two year old up to no good and other times they sound like one that's just got caught.

I'll probably go with option 3 unless I ever take the pups out and then I may change out the leads.

Nevin, the conductive paint does come into contact with pot casings so it should be grounded. However it does not show continuity--at least not enough to make my meter chirp with the probes in contact with the paint itself much less with the paint and the pot casings. Previous times in other guitars it has, but not his time.

Curtisa, thanks for all your help over the last few days. I'll let you know if anything new develops.

SR

[Prostheta]

Twisted pairs of cables work really well. You probably already know this trick, but if you chuck up the ends of the pair in a hand drill it'll twist them up beautifully but you'll need almost twice the length of wire.

[ScottR]

Twisted pairs of cables work really well. You probably already know this trick, but if you chuck up the ends of the pair in a hand drill it'll twist them up beautifully but you'll need almost twice the length of wire.

Clever idea. Makes perfect sense.

SR

[acpken]

A pot with a bad connection between the back cover (if you're grounding something on there) and the front screw bushing can cause the problem you have. It's called a 'high impedance short'. How does this work? When pots are made, their back covers are just held on by bending tabs over the matching areas on the front bushing. Dirty tabs on covers don't ground too well, so the cure (if you're using pots with brass screw bushings) is to pull the pots out and solder one of the pot's back cover tabs directly onto the bushing. If you're using pots with cheap zinc screw bushings, junk the pot. Or if you're cheap, solder jumper wires from the back of each pot to another pot.

I had this problem once with a pull pot on a new Strat, and it drove me insane... for some reason the side of the switchbox on the back of the pot was used as a ground point, but if you measured between the solder blob on the back of this one pot and the pickguard shielding foil, you got varying resistance. I replaced almost every part of the control system in this guitar before I finally figured it out. :barf:

ken

Edited November 16, 2013 by acpken

[ScottR]

That's good info to have, thanks. As a point of closure to this issue, I've concluded that the problem was a combination of my dirty house current, the unshielded wire phenomenon that Curtisa described and my own paranoia that I screwed something up. It has been played in other locations and been declared to sound like all strats always do buzz wise. It currently sounds normal at my house too.

SR

[Prostheta]

Well we get a lot of that here actually. Seems that I don't get a "proper" earthing for our electrics so all my passive instruments hum like crap unless I use wireless. Even a power conditioner (more a power strip actually) doesn't rectify the issue. I popped my electrical neon indicator screwdriver against the chassis of this PC rack and bing! it lights up. Kind of scary at first, me thinking that the chassis was at live potential.

[acpken]

It has been played in other locations and been declared to sound like all strats always do buzz wise. It currently sounds normal at my house too.

SR

ScottR, it sounds to me like your Strat is completely normal. Fenders always seem to have some kind of buzz to them sometimes, it's the nature of the beast.

Um... Prostheta, it sounds to me like you live in an old house or your house might have bad wiring in it. You may need an isolation transformer between your amp and the wall power to make your rig quiet. FYI... Neon bulbs fire (light) at 60 to 68 volts. If your neon light is lighting up between your rack and a known ground, there is enough volts there to hurt you.

Do you have a plugin wiring tester for your house wiring? You plug this into an outlet, and it has three neon lights on the front - two amber lights and a red one. The lights on the front light up in different combinations depending on how the house wiring is configured. This tells you definitely if you have any bad wiring, and exactly which wire is the problem. I use it every time I play somewhere, and it keeps me from getting 'surprises'.

ken

[curtisa]

FYI... Neon bulbs fire (light) at 60 to 68 volts. If your neon light is lighting up between your rack and a known ground, there is enough volts there to hurt you.

More likely is that his PC rack is earthed correctly and his body was capacitively charged sufficiently to light the neon. False positive/negative readings (amongst other safety concerns) with neon and non-contact voltage testers is a good reason why they're frowned upon in the electrical industry as reliable methods of detecting the presence of voltage.

[Prostheta]

Totally. I use mine to prise things open or stab items that need en-holing. Sometimes as a driver too.