The issue you're describing is definitely a grounding issue.

3. Grounding. I will need to run a ground wire to the bridge from the volume

If you haven't done this, I suspect this is the primary cause of your issues. Un-grounded conductive parts act like a big antenna. If the bridge isn't grounded, neither are the strings or tuners. All are acting like an antenna for noise.

4. Ground the volume to the shielding paint in the control cavity with a a grounding screw and tab.

Also good practice.

I followed the diagram other than point #4. I used copper shielding tape for all cavities. Continuity was great. Used wires to connect cavities. Unfortunately, the guitar had terrible noise.

Was there continuity between all points in the grounding of those cavities? Anywhere where you added shielding, it needs to be connected to the common ground. If it isn't grounded, it isn't shielding. It's another big antenna for noise. If you have sections of shielding that don't have continuity to ground, there's another issue.

If you used carbon paint, it may simply be that you didn't add enough coats. Depending on the quality of carbon paint, you could require anywhere from 3 up to 6 coats to get proper continuity for shielding purposes.

1. Does this diagram look correct? I'm curious about the terminals on the 3 way switch. I have labelled 1-4. Neck pickup is grounded on the volume with the shielded cable, main wire then to terminal 1 on the switch for the neck pickup. Similar but main terminal 4 for the bridge pickup.

2. Curious what are terminals 2 and 3 used for? I saw a diagram online which had the main wire connected to both 3 and 4 and the other pickup to 1 and 2...This doesn't seem right?

Traditionally you'd use the commons as the output to the volume pot, which is why the standard diagrams show the pickup leads connect to lugs that join with other lugs. Emerson just does it differently. Kinda smart actually, to make it easier for customers without wiring experience to install. Only one lug per pickup. But, unfortunately, that means any traditional wiring diagrams won't help you discern what's happening in this one.

From what I can see in your picture, I would think the lug you labelled as 1 should be the bridge lead and 4 should be the neck.

 

The issue you're describing is definitely a grounding issue.

If you haven't done this, I suspect this is the primary cause of your issues. Un-grounded conductive parts act like a big antenna. If the bridge isn't grounded, neither are the strings or tuners. All are acting like an antenna for noise.

Also good practice.

Was there continuity between all points the grounding of those cavities? Anywhere where you added shielding, it needs to be connected to the common ground. If it isn't grounded, it isn't shielding. It's another big antenna for noise. If you have sections of shielding that don't have continuity to ground, there's another issue.

If you used carbon paint, it may simply be that you didn't add enough coats. Depending on the quality of carbon paint, you could require anywhere from 3 up to 6 coats to get proper continuity for shielding purposes.

Traditionally you'd use the commons as the output to the volume pot, which is why the standard diagrams show the pickup leads connect to lugs that join with other lugs. Emerson just does it differently. Kinda smart actually, to make it easier for customers without wiring experience to install. Only one lug per pickup. But, unfortunately, that means any traditional wiring diagrams won't help you discern what's happening in this one.

From what I can see in your picture, I would think the lug you labelled as 1 should be the bridge lead and 4 should be the neck.

Thank you for the thoughtful response. My issue may have been been with the shielding tape and continuity. I have decided to use MG Chemicals 841WB-150ML Grey Super Shield Water Based Nickel Print Conductive Coating, 150 mL. I will add more coats for sure. I have three on there so far with ample time to dry in between.

Yes, Lugs 1 and 4 are where I place the main wires for the pickups - so just leave 2 and 3 empty? I'm curious why they are there?

I think adding the shielding wire to the shielding paint can't hurt, But I need to build up some more coats.

We'll see

 

if your tele has a copper bridge plate, or a steel plate of any type you do not need to ground the bridge. The ground wire coming from the pickup grounds that plate and through the mounting screw it grounds the bridge. You do not need a ground between the two pots, that is what the metal control plate is for. if you paint a little shielding paint so it can touch the control plate you do not need to hook up a wire for that either.

As for the wiring, use this diagram instead. But remember, the shielding on the wire is your ground assuming you have gibson braided wire pickups.

 

Check the wiring at your output jack. If it hums loudly when you touch the metal parts like the control plate you may have the wires reversed. Hot to tip, ground to sleeve is correct.

 

Yes, I thought this, but its an Emerson pre-wired assembly...I will check later...one of the wires was snapped off upon delivery. Maybe I should re- do the input

 

BTY, looks like the Emerson Harness is using 50's style wiring, so if you want that as opposed to modern style wiring you will have to move the cap

Also you show the hot wires from both pickups touching the back of the pot and the lugs on the switch. The hot wires do not go to the casing, only the ground wires. IE both blue wires go directly to the proper lug and do not touch the pots

 

My drawing was done a bit quickly. I have the shielded cable of both pickups soldered to the back of the volume pot, then only the hot inner soldered to lugs 1 and 4 (neck and Bridge)

Is it could practice to have the braided cables covered with tubing and only exposed in the areas for grounding?

 

This was my first attempt:

• maybe bad soldering joint?
• Should I but rubber tubbing around all the access braided cable?

As mentioned Ive now gone with shielding paint and will add another ground to the control cavity paint.

 

The braid on the neck wire is too much/too long. Cover it in tubing or cut it back to the pot. If the braid touches any of the lugs you are causing a short.
Also the bare wire touching both pots is causing a ground loop. The pots are already grounded through the control plate. Keep the cap grounded to the pot, but the snip the wire between the cap and the tone pot at both ends. The sections circled in yellow are incorrect.

Also add a small sliver of the tape to go outside the control cavity so the control plate is touching the tape. Or you can use a wire to make sure both touch.

 

The braid on the neck wire is too much/too long. Cover it in tubing or cut it back to the pot. If the braid touches any of the lugs you are causing a short.
Also the bare wire touching both pots is causing a ground loop. The pots are already grounded through the control plate. Keep the cap grounded to the pot, but the snip the wire between the cap and the tone pot at both ends. The sections circled in yellow are incorrect.

Also add a small sliver of the tape to go outside the control cavity so the control plate is touching the tape. Or you can use a wire to make sure both touch.

View attachment 506342

Thank you for the response:

1. Yes, I thought the wires were far too long and may be causing some issues. I will shorten them a bit and use some tubing especially around the switch.

2. So the bare wire connecting the tone and volume is not needed? This is how the assembly arrived from Emerson. But confirming that this not needed for my setup and would be detrimental?

3. The bridge on this guitar is a 1/2 bridge. Therefore I have a ground wire that rest under the bridge and connects to the volume pot. You can actually see a bit on an imprint of were the old wire was.

 

this is obviosuly the bridge route, but notice how the tape is outside the cavity? Do the same for the control plate cavity so when you mount the plate it touches the tape..

 

the bare wire between the pots is for tele's with rear routes. (think warmoth with no plate visible) The metal control plate and the wire at the same time is called a ground loop. It can cause ground loop hum. The loop acts like an antenna and gathers EM noise....

You don't need to shorten the entire wire, just make sure the braid cannot touch any lugs anywhere. Consider all lugs hot ( 2 are not but for sake of argument) So if the braid hits a lug it will short. Heat shrink, rubber/plastic tube/ electrical tape etc.... or just cut all the braid away between the pot and the switch. The braid can touch the pot casing, but nothing on the switch and no lugs.

The bridge wire is fine, it needs to be there. But your control plate should also be touching the tape somehow. Either directly by overlapping it like the photo above or by using a wire from the plate or the back of a pot to the tape. You can use a crimped eyelet between the pot and plate or solder it to the pot, use a crimped eyelet and a screw into the copper tape. (you can try soldering it to the tape)

 

the bare wire between the pots is for tele's with rear routes. (think warmoth with no plate visible) The metal control plate and the wire at the same time is called a ground loop. It can cause ground loop hum. The loop acts like an antenna and gathers EM noise....

You don't need to shorten the entire wire, just make sure the braid cannot touch any lugs anywhere. Consider all lugs hot ( 2 are not but for sake of argument) So if the braid hits a lug it will short. Heat shrink, rubber/plastic tube/ electrical tape etc.... or just cut all the braid away between the pot and the switch. The braid can touch the pot casing, but nothing on the switch and no lugs.

The bridge wire is fine, it needs to be there. But your control plate should also be touching the tape somehow. Either directly by overlapping it like the photo above or by using a wire from the plate or the back of a pot to the tape. You can use a crimped eyelet between the pot and plate or solder it to the pot, use a crimped eyelet and a screw into the copper tape. (you can try soldering it to the tape)

Thank you. that explains lot.

I wonder if the ground loop you referred to was the root cause of the noise I was experiencing. Felt like I was channeling the spirits when I tilted the guitar towards the lights....I have pulled out of the tape and now have used shielding paint. So you suggest that I have a wire from the shielding paint, to the volume and then also to the metal control plate?

I guess I could use a bit of copper tape that touches the shielding paint and also contracts the underside of the control plate?

Thank you!

 

the wire from the paint to back of pot OR the cavity plate, not both. Yes you can let some of the tape/paint spill over the edge so it touches the plate, then no wire required. With control plate installed tape off the edge with masking tape, remove the cover. Paint a small stripe but don't touch the tape. that way it will stay invisible when the plate is back on

 

Okay, I just learned a lot - thank you. So any tele that has a metal control plate...the wire can be snipped between tone and volume - on these Emerson units - as this creates a ground loop? I have a 4 way switch Emerson arriving today for another guitar. Its a more standard set up with Fender telecaster custom shop pickups. 3 wire neck and two wire bridge...standard telecaster stray plate on that one.

I just needed to have a tele with two p90s...the routing turned out well

 

You don't have to cut it. Try it first, if it hums then cut it. Ground loop hum is not a guarantee. But if you do suffer from the ground loop hum and you have a loop it won't hurt to break it. I'm sure there are tons of people out there with teles on a control plate with the ground wire. But you'll notice a lot of tele wire schemes don't show the pots ground together because most tele's are front route with a control plate. There is a good reason Gibson does not wire up a Les Paul like shown below....

Understanding Guitar Grounding And Common Mistakes | Fralin Pickups

Guitar Grounding can be an elusive subject, but it doesn't have to be. Learn from Fralin Pickups the best practices for Guitar Grounding.

www.fralinpickups.com

 

Just a quick follow up. Maybe this will help someone down the line:

An email response from Emerson

"Please don't cut that grounding bar we have in place, it won't cause any ground issues (its there to help with structure and to prevent ground issues) Most controls plates these days do NOT provide a proper ground due to poor plating or even some/a lot of new one being made out of aluminum which is not conductive)

Your diagram looks good"

 

so your harness guy thinks Gibson and Lindy Fralin to name a few are full of shite.... No offense but I'll listen to Lindy and Gibson.

 

Yeah, i dont know...just passing on some info...I'll install all this weekend and see

 

Pots not connected by wire, Why? because there is an aluminum shield to ground the pots.....

 

Dead quiet, in a good way. Thanks for everyone's help.

May put the black guard on

This was my first ever control cavity route (enlargement ) and pickup route (neck) project....all good 👍

 

I read through but may have missed it, what was ultimately the problem/solution?

 

Project was to add a neck p90 with a new route and route a larger control cavity, upgraded wiring to 500k pots, replace pickups with Seymour Duncan vintage p90s...guitar is a fender Noventa

I assembled everything back together but had tremendous noise with the guitar

I changed a few things listed in no particular order:

1. replaced copper shielding tape with shielding paint.... It took 4 coats to get 100% connectivity between all cavities

2. Re- did the jack soldering for both white and black wires on both ends of the Emerson harness ( in hindsight I think this may have been the sole issue)

3. Added a ground from the back of the volume to a lug screwed into control cavity shielded paint

4. Cut back extra length of braided wire from p90s. Put tubing around all other parts of braided wire

5. Ensured shrink tubing was used around the three way switch

6. Took time with soldering grounds, and shielded cables to the volume pot as per my diagram above

I think that's it...

 

Just an update...this project is done
Thanks for all the help. This was the first ever route of a new pickup cavity for me. Turned out 10/10
2 Seymour Duncan vintage p90s, Emerson wiring, bone nut, etc...

Just can't decide between blackguard or creame... currently has black

 

I am wiring a Tele up with 2 P-90’s, one volume and tone, and a 3way toggle switch. I have not found a wiring diagram for a rear cavity, and not a front plate. Some say to use 250k pot instead of 500. Can someone reference a diagram for this?

 

Cool project....I used the 500k pots as per my pics above....very hot pickups, but then again I play with volume around 8 or so....I hope you find what you need...I eventually sold this guitar to a local buyer...he was very pleased with the set up

 

The guitar has terrible noise because of the single coil PUs.
Unless of course the amp is noisy or the fx pedals are noisy...
The entire insides, needs to be shielded including the jack tunnel and the pickguard.
Shielding paint is usually not enough and I recommend you put conductive adhesive copper foil over the shielding paint.

(most shielding paint is pretty weak) unless you buy the good one which is fairly expensive.

You can either use humbucking P 90s or use a dummy coil inside the guitar.
There's plenty of humbucking PUs that have similar sound to single coils.

 

The guitar has terrible noise because of the single coil PUs.
Unless of course the amp is noisy or the fx pedals are noisy...
The entire insides, needs to be shielded including the jack tunnel and the pickguard.
Shielding paint is usually not enough and I recommend you put conductive adhesive copper foil over the shielding paint.

(most shielding paint is pretty weak) unless you buy the good one which is fairly expensive.

You can either use humbucking P 90s or use a dummy coil inside the guitar.
There's plenty of humbucking PUs that have similar sound to single coils.

There's a few errors in this and a following comment. Single coils are not inherently "terribly noisy".
A 'noiseless' P-90 (stacked) is called a P-100.
You don't need to shield tunnels if you use the correct wire type. You don't necessarily need to shield the pup cavity or pickguard if the pups are potted.
Epiphones aren't even all made in the same country, never mind by the same manufacturer and haven't been for decades. Specific build contracts are contract specific and in the case of Epiphone even if Saein gets the specific contract, manufacture could be in their original Korean factory or their newer one in China. I've had both Korean and Chinese Saein built higher end Epiphones.
The contract for the Epi Joe Pass I owned went to Unsung, Korea though.
To put the reality of guitar manufacture in perspective, Ibanez was using 14 different manufacturers in the 1980's, not just Fujigen.

 

This is the body and neck I need a wiring diagram for. I am not sure whether I am going to put the pup selector in front or behind the vol and tone.

 

Congrats on getting this resolved.
For others referring to this thread for similar issues, it's not necessary to do a full body cavity shielding.
Just do the pups.
https://www.premierguitar.com/diy/mod-garage/shielding-single-coil-pickups

 

Congrats on getting this resolved.
For others referring to this thread for similar issues, it's not necessary to do a full body cavity shielding.
Just do the pups.
https://www.premierguitar.com/diy/mod-garage/shielding-single-coil-pickups

I would really appreciate if anyone could help me with a wiring diagram for 2 P-90s, 3 way toggle, volume and a tone control. I have some good paint and copper tape, conflicting opinions of what works. That is why I always ask the folks here for opinions. I ask a pile of questions, that is how I learn. Most of the folks here do not get pissed answering questions. That is why I keep asking questions!

 

Is 500k pots the standard for P-90 pickups?

 

It is often difficult to see possible issues, errors on a pic...but it is better than no pic.

What is soldered here?

Are all of these joints soldered well. Some look a bit "iffy"...

 

It is often difficult to see possible issues, errors on a pic...but it is better than no pic.

What is soldered here?

View attachment 592479

Are all of these joints soldered well. Some look a bit "iffy"...

View attachment 592481

I can’t quite make out what is in the first picture? The solders on the switch are questionable! Lol
The tone and switch work as the should, glorious sound!

 

Good eye...I've read that 65% of all faults are due to grounding.

 

The other 45% being blamed on the person at the soundboard...

 

Symptoms:
My guitar buzzes and hums.
When I touch the strings, the noise stops.

That's because the guitar is not shielded.

Single coil pickups, un-shielded guitar, are the sources of this noise.
The 2 sources of noise add together.

The more "gain" the amp has = the louder this noise will be.
The more "gain" the effects pedals have, the louder the noise will be.

The people at the factory who shield these guitars are not idiots.
They are professionals.

Yes, this:

Yes, this:

Yes, this:

Yes, this:

Wake up and smell the coffee.

 

 

Pour another cup.