Wiring trouble shooting

[DesmoDog]

As a warm up for my Warmoth build, I built a kit guitar that I'e had sitting around for about 25 years.

I plugged it in last night and have a question on wiring... here's the problem.

When the tone nknobs are turned up there is a hum. With them turned down there's no hum.

When I touch the tuners/strings/bridge the hum gets louder. When I touch the output jack the hum gets quieter.

Strat copy, no lining in the cavities, small shield on the pickguard just under the control area. It happens on any setting of the switch, if the tone knob is turned up, it's noisy.

Would shielding things help, or is this indicative of other problems like a flakey ground or simply trash components or ????

Electrickery and I don't get along well so I'm not sure where to start looking for a fix. This isn't what I'd consider normal "noise", it's too dang loud for that...

 

[erock]

I'm guessing a ground loop.

follow all your grounds, and see if there is any area where there is more than one path to ground (the sleeve on the output jack)

it is a wild guess though

 

[drewfx]

Make sure tip and sleeve aren't reversed at the jack.

 

[BigBeard]

:doh:
Throw that guitar out of a 10th story window, works every time!!!!  Fixes up any guitar problem from wiring issues to intonation problems to flaws in the finish 


sounds to me like you don't have that tone control wired properly and you don't have a string ground.

I didn't shield my warmoth, and it's dead quiet.  Shielding helps, but doesn't solve the problems that some think it does. 

 

[Dan025]

Make sure tip and sleeve aren't reversed at the jack.

very easy to do, i still have a tendance to forget which solder lug goes to the tip and which goes to the sleeve. i've made the mistake being in a rush before.

 

[BigBeard]

seriously you gotta take your time on the wiring..........

I put on a pot of coffee and wait till everyone goes to bed before I start

 

[DesmoDog]

:doh:
Throw that guitar out of a 10th story window, works every time!!!! 

We haven't got many (any?) 10 story buildings around here or I might... maybe I'll let one of my dogs bury it in the yard?    :toothy11:

Truth be told I'm losing my enthusiasm for this project. When I went to put the strap knob on it the damn screw broke... below the surface. Grrr... cheap POS kit... add a few other issues to the list plus the fact the Warmoth body is supposed to show up on Wednesday, and, well... "Hey, Sophia! Ya want a new toy, girl? Huh? Do ya?  Take it outside.... good girl...."

BTW - the pickguard was prewired, I may have reversed the leads on the output jack but other than that...

 

[erock]

seriously you gotta take your time on the wiring..........

I put on a pot of coffee and wait till everyone goes to bed before I start

I tend to burn my hand when i do this. Now I just wait till the little one is in bed.

the wife can spare me for a few hours of soldering, it makes me happier when my had isn't all blistered, so she doesn't seem to mind much.

 

[BigBeard]

seriously you gotta take your time on the wiring..........

I put on a pot of coffee and wait till everyone goes to bed before I start

I tend to burn my hand when i do this. Now I just wait till the little one is in bed.

the wife can spare me for a few hours of soldering, it makes me happier when my had isn't all blistered, so she doesn't seem to mind much.

I don't know how, but it always seems like I get the wiring started around midnight!!!!!  Every guitar I have ever worked on (even friends and referred work) gets it's wiring done in the wee hours of the night!  I guess I can think like a signal during that time of night!!!  It also sometimes forces me to wait till morning to test the guitar out also.  I get done with the wiring, and put it down before I test it!  When I get up, I had time to think about how I wired it and I go over it one more time

Seriously though, if you have a prewired pickguard, I'd bet you have the + and - reversed on the output jack.  And check your ground on your tremolo claw

TAKE YOUR TIME, BE PATIENT!!!!  YOU WILL BE GLAD WHEN YOU ARE DONE!!!  BE PATIENT, BE PATIENT, AND DID I MENTION, BE PATIENT

:doh: 10th story windows aren't manditory, throwing it into traffic out of a moving vehicle is pretty darn effective too, just watch for pedestrians.  Aim for under the wheels of say a logging truck or some other type of semi, your guitar problems will be solved  :icon_thumright:

 

[Alfang]

Ground Loop?  I wish everyone dealing with guitars would remove that phrase from their vocabulary, 

It's a non issue in  a guitar where we're talking 6-8 inches of wire. it just doesn't happen.

Ground loops have more to do withlonger runs of wire, or large diferences in impedance through multiple ground paths, inductance, capacitance or alternate load.

Its an electrical concern in that a ground loop may allow an alternate path for current which will bypass an over current device like a fuse or circuit breaker, that alternate path of return may allow for inductive heating in a conduit and burn things up.

But when we're talking miliamps, ground loops dont exist. Not in a controll cavity of a guitar. you could take every "ground" in your axe indepedantly to the output jack, or tie them in groups then to output and there will be no problems.  If wires arent shorted, or open, your not gonna get noise from anything, things might not work if you dont have it wired correctly, but noise won't just show up from so called ground loops.
If anyone wants to change my mind with a schematic of a ground loop in a guitar, feel free.

 

[erock]

Ground Loop?   I wish everyone dealing with guitars would remove that phrase from their vocabulary, 

It's a non issue in  a guitar where we're talking 6-8 inches of wire. it just doesn't happen.

Ground loops have more to do withlonger runs of wire, or large diferences in impedance through multiple ground paths, inductance, capacitance or alternate load.

Its an electrical concern in that a ground loop may allow an alternate path for current which will bypass an over current device like a fuse or circuit breaker, that alternate path of return may allow for inductive heating in a conduit and burn things up.

But when we're talking miliamps, ground loops dont exist. Not in a controll cavity of a guitar. you could take every "ground" in your axe indepedantly to the output jack, or tie them in groups then to output and there will be no problems.  If wires arent shorted, or open, your not gonna get noise from anything, things might not work if you dont have it wired correctly, but noise won't just show up from so called ground loops.
If anyone wants to change my mind with a schematic of a ground loop in a guitar, feel free.

I had a nasty one in mine, but of course mine is a "jerrycaster" which is a WGD guitar with on on board effects loop. I was getting some nasty noise out of it until i cut the ground wire of the effects jack sleeve because brass plate that was around both outputs was making a ground connection via the sleeves. I think I had another loop in there as well, but I can't remember it off hand. I could post a schematic that I drew in sharpie on paper, but that is kind of hard to read, and I also didn't have the brass piece drawn in on it.

 

[BigBeard]

I had a nasty one in mine, but of course mine is a "jerrycaster" which is a WGD guitar with on on board effects loop. I was getting some nasty noise out of it until i cut the ground wire of the effects jack sleeve because brass plate that was around both outputs was making a ground connection via the sleeves. I think I had another loop in there as well, but I can't remember it off hand. I could post a schematic that I drew in sharpie on paper, but that is kind of hard to read, and I also didn't have the brass piece drawn in on it.

Jerrycaster........................  And where are the pictures of your Jer?  I have an effects loop in my WGD and I have no issues with any noise in my effects loop at all!!!!  I lose a tiny bit of the highs in the cable for the effects, but the effects make up for that.  If I ever put a 'unity gain buffer' into the guitar, that would eliminate the high end loss I get with the cables.  When I run my t-bridge into the effects loop, I get no loss due to the preamp, so lately I have been using the cntrl x blend function and cutting the t-bridge out so I don't get the loss in the effects.  Works like a champ

Anyway,  I would love to see pics of your Jerrycaster!!!

 

[erock]

the pictures are here. http://www.unofficialwarmoth.com/index.php?topic=9791.0

I do have the buffer in, and it makes a world of difference. I used an EMG pa-2, took the switch off and jumpered it to the off position (it was only $30)

the loop was coming from the brass plate between the jacks, did you have that on yours? I know I've seen pics of yours (the lefty, right?) but I don't remember seeing that double input jack.

Since it's starting to warm in in Pittsburgh, I'll be bale to take some better outside pics of it soon.

 

[Cagey]

Ground Loop?   I wish everyone dealing with guitars would remove that phrase from their vocabulary, 

LOL! No kidding! Somebody simultaneously influential and unenlightened must have said that out loud one time, and it's been repeated and blamed ad nauseum for a variety of sins ever since.

 

[Dan025]

Ground Loop?   I wish everyone dealing with guitars would remove that phrase from their vocabulary, 

LOL! No kidding! Somebody simultaneously influential and unenlightened must have said that out loud one time, and it's been repeated and blamed ad nauseum for a variety of sins ever since.

all i know is that the more grounding and sheilding i do, the more noise i tend to get in the end. i'd never blame a ground loop because i don't know anything about it but i find that the simple wireing in an oem guitar is normally best. trying to improve upon it hasn't worked for me.

 

[Cagey]

Most of the heroic measures people take to shielding guitars is futile. But, noise is so annoying that most people will go above and beyond the call of duty to suppress it, no matter how ineffective the effort. There's at least a mildly satisfying peace of mind that comes with knowing you've done everything that can possibly be done to eliminate the dreaded scourge of 60 cycle (and its harmonics) hum, and even if everything they've done has no effect, they'll convince themselves that they've at least improved the situation.

 

[BigBeard]

the pictures are here. http://www.unofficialwarmoth.com/index.php?topic=9791.0

I do have the buffer in, and it makes a world of difference. I used an EMG pa-2, took the switch off and jumpered it to the off position (it was only $30)

the loop was coming from the brass plate between the jacks, did you have that on yours? I know I've seen pics of yours (the lefty, right?) but I don't remember seeing that double input jack.

Since it's starting to warm in in Pittsburgh, I'll be bale to take some better outside pics of it soon.

Hey bud, I just checked out your WGD, and WOW I really like what you have done with it!!  Yes mine is the lefty flame maple WGD.  You are in PGH?  I'm only 75 miles east of you.....! Go Pens!!  I used to have a delivery route through the 'Burgh,  I may have driven through your neighborhood!!  I'm starting to see a few people from PA on here, which is good...

The jacks on my guitar are on the side, both of them.  I am gonna have to look into one of those EMG pa-2. 

Well since we are essentially in the same neighborhood, we should jam sometime, after my finger heals (I smashed it pretty good with a hammer  :doh: )

I do like that guitar, it really turned out good  :icon_thumright: 

 

[erock]

Hey bud, I just checked out your WGD, and WOW I really like what you have done with it!!  Yes mine is the lefty flame maple WGD.  You are in PGH?   I'm only 75 miles east of you.....! Go Pens!!  I used to have a delivery route through the 'Burgh,  I may have driven through your neighborhood!!  I'm starting to see a few people from PA on here, which is good...

The jacks on my guitar are on the side, both of them.  I am gonna have to look into one of those EMG pa-2. 

Well since we are essentially in the same neighborhood, we should jam sometime, after my finger heals (I smashed it pretty good with a hammer  :doh: )

I do like that guitar, it really turned out good  :icon_thumright: 

I am in the burgh Where are you at? I am guessing Johnstown, as that is the only close city within that range. If so I usually head up there in the summer for the free folk fest. a nice little day trip to get out at stretch my city legs.


I'm down with jamming with other WGD guitars. hard to find like minded folks around here.
That preamp really makes it with the effects loop. I love having total volume control right on the guitar. if you decide to mod the pa-2 you want to wire it to the off position as that is Unity Gain, and the on position goes through the pot to boost it beyond unity. that switch is a pain to get off, and I had to do some creative wiring to get it to work (my soldering gun ripped off the pads when i took it off)

IMO the soul mate neck really make the WGD just that much more awesome.  :rock-on: