Have I grounded my guitar correctly?

AlexWilmot

Hi All

So I have finished off a guitar recently to the following Scheme:
2 Humbuckers/3-Way Toggle Switch/1 Volume/1 Tone/Individual Coil Taps



Everything works except for any variation with the levels on the volume and tone,
I have everything grounded to the volume pot and then one wire to the bridge,
I believe the reason for the lack of change with the volume is due to a grounding issue,

Do I need to reground everything differently than my single point on the volume pot?

Funkfingers

AlexWilmot said:

I believe the reason for the lack of change with the volume is due to a grounding issue.

In the G.E. diagram, some of the connections are implied rather than drawn in.

For example, the tidy way to connect each coil split ground is to the chassis of the same pot chassis as the respective DPDT switch.

The pot chassis grounds should be linked to each other.

Finally, a ground wire needs to run from your volume pot chassis to the ground terminal of the output jack socket. 

SteveRobinson

A photo of your wiring would help

Funkfingers

All stop! I think the diagram is erroneous.

The connections from the bridge/Treble position humbucker look wrong. Pulling up the push-pull pot knob fails to remove its stud (North) coil from circuit. Instead, it creates a parallel loop

SteveRobinson

No, it just shorts the other coil, presumably so that the two remaining coils are RWRP and humbucking when used together.

AlexWilmot

SteveRobinson said:

A photo of your wiring would help

I've just put new strings on, might be hard to get the scratch plate off to see underneath, (Strat type guitar), but I incorrectly said volume pot in the 1st post,

The grounds are all soldered to the "TONE" pot chassis as per the diagram where the Cap is to be grounded

ICBM

It sounds like you don't have a ground connection to the volume pot. The casings of both pots need to be connected together.

An outside possibility if you've done that is that when you bent the volume pot ground terminal back to solder it to the casing, you strained the rivetting to the track board - that will result in the volume control only making a small difference as you turn it down. If so, you can fix it by firmly clenching it back to the trackboard using a pair of narrow-nose pliers.

You can test which of these it is without taking the guitar apart - simply get the cut-off end of a plain guitar string, and wrap it around the shafts of both pots under the knobs. If the volume control now works properly, you just need a ground wire between the pots. If it doesn't, the terminal has lifted.

SteveRobinson

AlexWilmot said:

SteveRobinson said:

A photo of your wiring would help

I've just put new strings on, might be hard to get the scratch plate off to see underneath, (Strat type guitar), 

You'll have to remove it to fix the problem.

Put a capo on the 1st fret, slacken the strings and remove the neck. Then you can take the pickguard off, fix the problem and reassemble keeping the strings.

prowla

You do have the volume pot body connected to the jack sleeve, right?

That's where the earth comes in.

prowla

Also, what pots are you using? I'd expect them to be A500k (audio/log 500k).

AlexWilmot

prowla said:

You do have the volume pot body connected to the jack sleeve, right?

That's where the earth comes in.

Only have the middle lob connected to the Jack tip, all grounds are going to the tone pot chassis and then I have a wire from the Jack sleeve to the grounds I've made on the tone pot chassis,

I think this might be a problem then?

Funkfingers

Not saying' nuthin' without first seeing photographs of the wiring as it stands. 

ICBM

AlexWilmot said:

Only have the middle lob connected to the Jack tip, all grounds are going to the tone pot chassis and then I have a wire from the Jack sleeve to the grounds I've made on the tone pot chassis,

I think this might be a problem then?

If you haven't connected the volume pot casing to the tone pot casing, yes.

SteveRobinson

If everything apart from the volume pot earth is correct, turning the volume control would normally still give some variation in volume, it just wouldn't cut 100% at zero. 

ICBM

SteveRobinson said:

If everything apart from the volume pot earth is correct, turning the volume control would normally still give some variation in volume, it just wouldn't cut 100% at zero. 

Some, but possibly very little, depending on what it's going into. If it's into a 1M input impedance, it will only reduce the volume about the same as turning down to about 8 or 9 on a normal Log pot with a ground connection - even a 500K pot will only cut the signal down to 2/3 of the full level.

AlexWilmot

ICBM said:

AlexWilmot said:

Only have the middle lob connected to the Jack tip, all grounds are going to the tone pot chassis and then I have a wire from the Jack sleeve to the grounds I've made on the tone pot chassis,

I think this might be a problem then?

If you haven't connected the volume pot casing to the tone pot casing, yes.

Mystery solved! Well until I try it over the weekend

AlexWilmot

SteveRobinson said:

If everything apart from the volume pot earth is correct, turning the volume control would normally still give some variation in volume, it just wouldn't cut 100% at zero. 

That's exactly what happens, a slight decrease in volume but not much and still sound when in the "off" position

AlexWilmot

So I took her apart, added the ground to both pots... And same issue, but my ground looked a bit dry, will leave it for now until I change strings again and re do the grounds, it works and I can play it just no volume control

ICBM

If that doesn't fix it, can you post a pic of the wiring? There's likely to be something simple missing.

AlexWilmot

Hi Chaps

So I found the issue to be a poor connection coming from the volume pot to the ground,
however when I touch the bridge I get a buzz sound, is this normal? video below:

ICBM

Sounds like you may have the jack wired backwards, since touching the volume knob (which is also grounded) also causes a loud buzz.