I have notticed on my telecaster that I built (two p90's, 3-way switch, tone and volume knob) that I get a little hiss through my amp. I expected this since they are not humbucking pickups. What I did nottice that I was not expecting was when I touch the strings there is less noise and sometimes when I touch the chrome control knobs you can hear a very faint popping. I am wondering if that means I botched the ground connections? Any thoughts or is this "normal"? I have never had single coil pickups so I don't really have anything to compare them to.
Wiring questions-AKA I may have messed something up
- Thread starter Danuda
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jackthehack
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Sounds like the bridge isn't properly grounded.
Firebird211
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You really shouldn't hear any change in sound if you are touching the strings or the knobs. The bridge sounds like an inproper ground, for sure. The control knobs sound like they aren't grounded properly either. An ohmmeter would help you find the problem with them both. The bridge should be easy enough to fix, but for the knobs you will have to make sure they all have a common point of connectivity for them, even right to the tips of the pots. Some people use grounding rings to remedy this or just use a common section of grounded tape that the pots are mounted to. Some of the bad problems I have run into was from the assumption that all parts of the pot had good continuity through them, like with a push-pull, most of the time I find the switch not well connected to the pot electrically. It all depends on who makes it, but it's always a good idea to check with an ohmmeter/continuity meter.
Ok, I will have to check that then. It was my first soldering job so it is possible I messed up the wires and they don't have a good connection.
I grounded the control knobs from the back of the pots and the bridge is grounded with a wire that runs up to the bridge. I stuck it up through the hole and then screwed the bridge on top of it.
I grounded the control knobs from the back of the pots and the bridge is grounded with a wire that runs up to the bridge. I stuck it up through the hole and then screwed the bridge on top of it.
Firebird211
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Since you mentioned that they are soldered to the tops of the pots. I'm not sure if they are standard or push-pull pots, but it is very possible there is low conductivity from the back of the pots to the tips of the pots, where the knobs are attached. This would make the knobs very receptive to your touch, and if the connection comes and goes, so does your noise problem.
They are standard pots. I think I am going to pull the guitar wiring apart and start again. I must have a issue somewhere. I played around with it more yesterday and I definitely think I messed up a ground somewhere. Anything that I touch that is metal makes the fuzz sound stop. I tried the tuners, strings, bridge, control knobs and jack plate and they all did it. I am going to pick up a digital meter and test all the connections to see what I did wrong.
Firebird211
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If you are going to get the digital meter, you could use that to find your ground problem before you tear up everything and start again. One little tip I could offer is to fix one lead of the meter to the most common ground point in the control cavity, then start poking around and touching each individual ground point. You could just use the continuity "beep" or the ohmmeter to get a idea whats a good connection or not.
Ok, I will try that before I tear it up. If I can fix it easily I will just do that. if not I may change the way I wired it to this.
Imagine that the pots and switches are on a metal plate and the ground screw is attached to that with a washer. This way the pots and the switch are grounded just by being screwed into the plate. Does this look about right?
Imagine that the pots and switches are on a metal plate and the ground screw is attached to that with a washer. This way the pots and the switch are grounded just by being screwed into the plate. Does this look about right?
jackthehack
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Don't know what kind of bridge you installed, but most them have chrome and/or protective coatings even on the back of the bridge. Locate the area that sits atop the hole for the grounding wire and use a file or knife blade to scrape it down to bare metal. Solder the end of the wire to that, then feed it into the control cavity and solder to a common ground.
Firebird211
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That looks good. That would be a star grounding system, which should prevent any grounding headaches. If you get to that point and decide to rewire it, it wouldn't hurt to send the output jack ground and volume pot ground to the ground plate seperately. This would avoid one ground connection from getting broken by another if the volume pot ground were to disconnect.
I just checked my guitar with a digital meter and every single connection showed continuity. I am not sure what is causing that little buz now? I checked every ground point including touching it to the bridge and also the chrome tops on the control knobs and I got a tone on everything including the output jack. Any ideas on what could be causing the buzz. It isn't very loud, but when I turn up my amp it gets louder and touching the strings, bridge or control knobs stops the noise. The only thing that shows no contiuity is a hot to a ground, but I think that is what it is supposed to be.
Firebird211
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Other than just using the continuity buzz, sometimes the meter shows an ohms reading as well, or just use the ohms meter. You would want any ground connection much less than an ohm between points. The continuity buzz probably goes off for anything less than 5 ohms. I usually keep mine less than 0.1 ohms which is pretty much inaudible. Your new wiring scheme will probably be the best way to minimize any differences between ground points.
Ok, I will have to check that. I was just using the tone to test. When I touched one to the other some numbers popped up then disappeared to 0 and the tone went off. I don't really know how to use the meter so I will have to look up what I need to set it to to just test the ohms to 0.1.
As an aside, I tested my PRS SE singlecut and it actually does the same thing. Does that mean the wiring in it wasn't done very well as well?
As an aside, I tested my PRS SE singlecut and it actually does the same thing. Does that mean the wiring in it wasn't done very well as well?
Yeah, I was worried about that so I checked that when I was going over it last night. It was wired correctly. I am going to check the actual resistance today and see if maybe the solder joints are good enough for continuity, but bad enough to make noise.Cagey said:
Firebird211
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That's not really that bad either. :icon_scratch: How good is the cable that your guitar is hooked up too? The only concern I would have is how much those ground points are varying in a small space. Make sure the wire to the bridge has a good metal to metal connection, the wire isn't excessively long, and if you want to cut the resistance down you could use copper wires. The static sound on the knobs would be better eliminated if you took the ground to the front of the pots, through a plate, or ground rings, instead of being just grounded to the back of the pots. I don't know if the connections you have are far enough apart in resistance to cause a ground loop. :icon_scratch: It might be enough when you crank up the gain.
Firebird211
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So the fun begins. Good luck man. :rock-on:
Ok, I finished re-soldering all of the connections including re-doing the ground to the bridge. All of the connections are now .1 ohm or 0 with the majority just showing 0. The guitar is louder now which I imagine is from a better signal to the amp. Unfortunately the buzz is still there. I think I isolated where it is coming from. When I turn the tone all the way down to 0 the buzz disappears. I can crank the guitar up and my amp up and all I get is a nice hum from the pickups (except in the middle switch position because they cancel each other). Once I start turning the tone up though I start getting a buzz. If I touch any metal on the guitar the buzz goes away. Is it possible there is something wrong with the tone pot?
