Guitar Gets Noiser When I Touch Ground

[drewtimfan]

I have had a hell of a time wiring up my new guitar... Never had a problem before. But here is my problem.

I have everything grounded to a screw in the control cavity. I had everything shielded with aluminum tape.

I put the pickguard back on and it knocked off my hot wire to the jack. I soldered it back on and realized that my bridge wire wasn't connected to the bridge anymore because my wire was really shitty.

So i rewired just about everything except the jumpers on my phase and series switch. I used 22 gauge shielded wire.

Now everytime I touch any part of the ground, the hum gets worse. I stripped off most of the aluminum shielding except on the pickguard. I thought this might be the problem since everytime i touched the shielding, it started humming.

To top it off, all I have attached to my jack is the ground and everything is working properly.

Basically, I need to figure out why the ground is carrying a hot signal to my jack... There is nothing attached where the jack has the connection to the hot terminal. Nothing is connected to the hot, yet everything functions normally.

The second thing is everytime i touch the ground it hums. So I was thinking of taking every bit of shielding off because the shielding doesn't help at all. So could taking the shielding off of my pickguard solve the problem? Also when i try to ground it to my volume pot instead, everything goes off. Possibly because the ground terminal on it may have too much solder which flowed over to the pot case.

I am really dying here, have been wiring for hours and hours a day for the past 9 days. can you straighten me out please

Edited July 2, 2005 by drewtimfan

[lovekraft]

Replace the jack, and make sure you wire the new one up correctly - my guess is that's where your problem is.

[drewtimfan]

It was working perfectly at first. I can't imagine why the jack would be malfunctioning.

[silvertonessuckbutigotone]

Replace the jack, and make sure you wire the new one up correctly - my guess is that's where your problem is.

←

If I read what he said correctly, even if it was the jack, he didnt even have a hot wire soldered to the jack terminals. Could it be that the "ground" your connecting to the pickup screw is sending a hot signal to the "ground" and you connecting it to the wrong terminal of the jack (or maybe the jack is sending the "ground" from the screw to the hot conductor?)?

Overview:

Try switching the terminals your connecting the ground to.

or

Try not connecting the ground to the pickup screw. (BTW whats that for I've never heard of it)

if niether of those work,

Try replacing the jack.

[lovekraft]

...all I have attached to my jack is the ground and everything is working properly...

This means that he's getting a complete circuit with only one wire attached to the jack - since we both know that's impossible, the first step is to get a known good jack in there to sort out the rest of the mess. The hum makes me think that the ground and hot wires have been reversed somewhere, but it'll never get sorted untill the issue of the "miracle" jack is addressed - that's why I'd start there. Signal chain problems have to be addressed systematically, or you'll spend all day making no progress - FWIW, I watched a guitarist with 20 years of experience spend half an hour messing with a multitude of patch cords, his new Splawn head and his guitar with no results (it was cutting out randomly while playing) - as soon as we started at the amp and began working back up the chain, we found the culprit was a bad digital delay pedal that "...couldn't be the problem, it's only 5 months old!".

[thedoctor]

OR, it worked just fine last week. Or, second shift must have done it, or why would it just break? At a certain point, you quit using the "last for ever" and the "last time I used it" stuff and FIX the damn thing! I know that is a little strong language for me but< as Bart Simpson would say, I didn't do it, nobody saw me and you can't prove it. It be broke. Fix it.

We already know that there is a man-of-color in charge of the bulk cellulose storage.

[drewtimfan]

I reversed the wires at the jack. When I did this the ground no longer made the guitar hum. But when i touched any part of the hot circuit it started to hum.

I am going to replace the jack now and i will let you know what happens

[drewtimfan]

Used a brand new jack out of the packaging --- same problem.

I have looked for out of place wires and I can't find one.

The neck pup goes to a phase switch then to the rhythm circuit for the jazzmaster.

The lead then goes out of the rhythm circuit to the pup selector. A jumper goes from here to the series switch.

The bridge ground is wired to the series switch. the hot lead is wired directly to the pup switch.

There is no hot wire going to ground. There is no ground wire going to hot.

The only last thing i can think is that the volume pot has a lot of solder on it. Perhaps the volume ground is grounding itself to the pot via the solder. It doesn't seem like this would cause the problem but maybe.

I put a brand new capacitor on. I have rewired this thing with all shielded cables. This just doesn't make sense.

I try grounding the grounds to the volume and tone pot, but it kills the signal

[lovekraft]

OK, a few questions:

1. Do you have a wiring diagram/drawing you can show us?
   
2. What kind of pickups are you using?
   
3. Is this wiring setup a proven layout, or is it a custom idea?
   
4. What kind of switches are you using (please be fairly specific)?
   
5. Got any pics that might help get us on track?
   

I'm sure this bunch can fix this (collectively, we are pretty good! ), but it's gonna take a lot more than what we've had to go on thus far.

[drewtimfan]

1Do you have a wiring diagram/drawing you can show us?

Here is the Link: Jazzmaster Schematic

2What kind of pickups are you using?

2 wire Jazzmaster Single Coik

3Is this wiring setup a proven layout, or is it a custom idea?

Most of it is the jazzmaster schematic, but I added in a phase switch and series switch. The way i wire the phase switch is exactly like the duncan schematic. The way i wire the series switch is from deaf eddie.

4What kind of switches are you using (please be fairly specific)?

I am using dpdt mini switches, 1 meg volume and tone pots, dpdt slider switch for circuit switching(lead and rhythm). And a 3 way pup selector.

5Got any pics that might help get us on track?

No Pics yet.

I have the capacitor running to the star ground. Then touched it to the volume pot and the hum goes away. However this causes the tone control not to work.

Edited July 2, 2005 by drewtimfan

[drewtimfan]

Just thought i should add that when the tone control is all the way rolled off, it doesn't get noiser when i touch ground.

It won't really be a problem if i don't ground the bridge. Because i won't be touching any part of the ground

[drewtimfan]

Here is another update:

I isolated everything part of the system.

First I took out the rhythm switch(switches between two sets of volume/tone controls). Still got noisy when i touched ground.

Then I took out the phase and series switch. Didn't make a difference.

Took off the tone pot. Same problem

Used a different pot for volume, with no tone control wired. Still the noise when i touch it.

Everything is working properly, just noise when i touch the ground.

Here are my only last thoughts:

1- I have never used a les paul style selector before. There a 4 terminals. I used the left terminal for bridge. Right terminal for neck. And the two middle terminals i soldered together and sent out to volume pot. Maybe this is not right????

2- Just deal with the problem. It won't matter if it hums when i touch a part of the ground if the bridge is not grounded.

3- This problem is normal(which i can't fathom is true). Because at one point i finagled it to where it didn't get noisier. But when i finagled it, either the tone control or rhythm switch didn't work.

4- By some weird hex on me, all the components I have used are somehow bad.

[lovekraft]

No, it's almost definitely a wiring cockup, especially since you started with a fairly complex wiring diagram to begin with and then added even more options - time to start over. The very first thing I'd do is rip all the wires out completely to get rid of any previous problems, and wire just the 3-way toggle and the master volume and tone pots (be sure to include your bridge ground at the star ground point). Once that's working correctly (and only once it's right), add the rhythm switch and pots. If you can't get both of those steps completed, you've either got a bad component or you're having conceptual trouble with the actual wiring, and we'll have to hunt that down.

[drewtimfan]

I tried wiring just selector, volume, tone, output jack. Didn't make a difference. Tried selector, volume, output jack. Same thing.

Both potentiometers work. They meter right 987k and 975k. They work.

It doesn't get noisy when the tone control is all the way rolled off. When I grounded the cap to the star ground, and also to the tone pot, the noise went off. But in this case the noise went away, but the tone control doesn't work.

So this makes me think that it is a potentiometer problem. But it would seem if they meter correctly and work correctly when connected right, it would be hard to peg this as the problem. I guess I will try different pots and post the results

[thedoctor]

Have you tried a different cord to the amp? If you followed LK's instructions and still have this problem, the man-of-color is still there.

[lovekraft]

OK, let's break it all the way down - wire the bridge pickup hot wire directly to the jack and set up your star ground (don't forget the bridge ground). If that eliminates the problem, wire in the volume control, and if you're still not experiencing problems, add the tone control. If at that point you're still good, disconnect the bridge pickup hot wire and hook up the neck pickup hot wire in exactly the same place. Again, if there's no problem, disconnect the pickup and wire the selector switch output to the same spot, wire the pickups to the selector switch, and try it out. Stop if the problem(s) shows up, and get back to us.

[drewtimfan]

Well after a long weekend of shows, I came back to work on the jazzmaster. I wired both pickups directly to the output jack. Hot to hot; Ground to Ground. The pickups were getting output, but when i touched the ground wire it made the same noise.

Now i guess this tells us that it is the pickups. They are brand new straight from the seymour duncan custom shop. So i doubt there is something wrong with the pickups. At least i should hope so for $175 pickups.

So the only thing I can think of is that the shielding of the pup cavities is making it noisy. That is the only place that the shielding is left. I don't know though. What do you think guys? Lovekraft?

[thedoctor]

Have we checked that cord yet?

[drewtimfan]

Yeah used different cords. But I have an update.

I was using jacks with three terminals. Dind't know there was much of a difference. So i got a jack with two terminals.

Wired it up one by one and got all the way through with everything. No buzzes on the ground circuit.

But the hot circuit does buzz when it is touched. I called seymour duncan and they said this was normal.

So that leaves me with one last problem. The rhythm circuit switch is connected to the pickuard through screws. The switch has no ground. It isn't supposed to be grounded. Now everytime i touch the screws on the pickguard it buzzes not much, but you can still hear it. Duncan told me to ground the casing, but the whole switch is hot, so when i ground it, it kills the circuit.

So it is just left to figure out how to not get the screws to buzz. Somehow use electrical tape to keep the metal from touching?

[frank falbo]

How could the switch chassis be hot? You need to remedy that. Then you can ground the switch chassis. No offense, but if you wired the wrong terminals on the 3 pin jack, you just might be responsible for the switch chassis being connected to hot.

[drewtimfan]

OKay well i just about solved all my problems. But of course one problem leads to another with me.

The hot wire that went from the rhythm switch had a little soler spill over and touch the switch case. This was causing it to be hot.

I fixed everything and was getting ready to put the pickguard on when i noticed that now there is a little buzz all the time, but when i touch the ground circuit it stops buzzing. Thanks for your help guys, hopefully i will figure this one out on my own. Thanks again.

[lovekraft]

...there is a little buzz all the time, but when i touch the ground circuit it stops buzzing...

That pretty much describes any single coil setup that's not perfectly shielded. Sounds like you've got everything sorted out, but you need to reinstall the shielding. Well done!

[drewtimfan]

the buzz is different from the single coil hum. The hum is always there from the pickups. But when I touch the ground, the buzz goes away.

It is just a buzz over the hum. So we have hmmmmmmmmmmmm and bzzzzzzzzzzzzzzzzzzzzzzz. When i touch the ground no more bzzzzz, just hmmmmmmm.

[drewtimfan]

What would my new problem be a symptom of? It gets quiet when i touch ground/

[lovekraft]

Lack of shielding. When you ground your body by touching a grounded connection, you act as a ground plane, shielding the guitar.