Strange results with Seymour Duncan Jimmy Page wiring mod

[sickman82]

This is a bit of an embarrassing one but I need some help with the wiring I just did on my Les Paul copy. I followed the Seymour Duncan diagram.. http://www.seymourduncan.com/pdfs/su...s/jp_style.pdf

When originally wired up, I followed it to the exact detail.. plugged in, and I got really bad ground hum that was cancelled out with me touching strings/bridge etc. So, I linked the pot casings from bridge vol - neck vol - neck tone - bridge tone. This seems to have sorted out the ground hum. Almost.

Another problem is the volume pots don't seem to be grounded properly as when set to zero there is bleed through of the guitar. The volume pots are grounded from lug to casing. Also, when the bridge tone switch is pulled for out of phase, the ground hum is back. All ground connections check out with a DMM.

Lastly, when the neck tone switch is pulled, for series wiring.. if you select the bridge pickup, it is muted - or at least would be if there wasn't the grounding issue I outlined above. Is this part of the deal? I realise that series wiring is useless without both pickups selected.. but if I wanted to switch from middle position in series, to bridge alone, I would have to push the neck tone pot and flick the pickup selector. Hardly a practical design!

Any ideas before I start from scratch with a different diagram? I checked all my wiring and it seems good to me, no mistakes that I can see. I've wired up plenty of guitars, but this is my first attempt at anything as complicated as the JP wiring.

[Jazz P Bass]

Man, that is one confusing wiring diagram.
The switch positions are not indicated.
There is not a path from the pickups to the pots.
Is there an actual schematic available?

[sickman82]

Not sure about a schematic, there are quite a few different diagrams out there if you do a quick google search. So this seems to be one of those things where there are many ways to skin the same cat, whether a schematic would even match up to this diagram is doubtful.

[sickman82]

Just found this... http://music-electronics-forum.com/t1079/

Scroll down until you find two images together. They're the complete diagrams. They look really confusing too though!

[Jazz P Bass]

Well. here is a schematic that I found.
It is a bit more illustrative, as it shows the switches.

[big_teee]

Well. here is a schematic that I found.
It is a bit more illustrative, as it shows the switches.

To Damn Complicated for me!
I would forget that the Primary Objective was to Play Guitar!
B_T

[David Schwab]

To Damn Complicated for me!
I would forget that the Primary Objective was to Play Guitar!

So then play a guitar with one pickup and no controls if it's that confusing! Or better yet, an acoustic guitar! Then you don't have to worry about knobs and tones and stuff.

To the original poster. You say the pots have the ground lug soldered to the back (can) of the pot. Do you also have aground wire attached from that to the output jack's ground? Duncan doesn't show all the pots connected to ground, but they have to be. You can run a wire from one pot back to the next and then one of them can go to the jack's ground.

[big_teee]

I like controls, and Pots and Stuff, but 4 Pots, and 4 Push Pulls is IMO a little much.
I have done some 4 POT and 2 Push Pulls.
You can get split and Phase reverse wit that.
Anyway have fun with JP Design.
T

[David Schwab]

I like controls, and Pots and Stuff, but 4 Pots, and 4 Push Pulls is IMO a little much.
I have done some 4 POT and 2 Push Pulls.
You can get split and Phase reverse wit that.
Anyway have fun with JP Design.
T

I think it's over kill myself, but you don't have to use it all.

[sickman82]

David.. Yep, I have a ground wire from the back of the pots to the sleeve of the output jack. I'm puzzled. I don't understand why Seymour Duncan don't link the pot casing together with a ground wire.

I'm just gonna attempt a different diagram I reckon, the one I posted above that was designed by a forum member looks too unclear to me.. Too much potential there for mistakes.

It is overkill, but it's interesting! So many options, so many different sounds.. Why wouldn't you want that?! It's like an artist having as many colours as possible on his palette.

[David Schwab]

It is overkill, but it's interesting! So many options, so many different sounds.. Why wouldn't you want that?! It's like an artist having as many colours as possible on his palette.

Oh believe me, I've done stuff like this in the past. Back in '76 I had six toggle switches, a rotary switch, and five knobs on my '73 Rick 4001 bass! I had a phase switch, series/parallel, and series/parallel for each pickup (humbuckers). Then I had a six position Varitone midrange choke. The next year I added a preamp with active bass and treble controls.

What I found after a while was a lot of good tones, and even more similar or useless tones. Some would translate to guitar better, such as the out-of-phase stuff. I had something similar on my guitar.

[Jazz P Bass]

I don't understand why Seymour Duncan don't link the pot casing together with a ground wire.

Aahh, but it is indicated.
There is a small box that shows a solder blob, with solder marked in it.
They specify that all markings of this nature are to be grounded together.

[sickman82]

Aahh, but it is indicated.
There is a small box that shows a solder blob, with solder marked in it.
They specify that all markings of this nature are to be grounded together.

That's unusual though, usually they have those blobs linked with a wire as you would expect. I had missed that though, thanks for pointing it out. By 'location for ground connections' do they mean ground together?

David, that picture is amazing! I love it.. that bass, I bet it roared! Look at all the knobs! You still have it?

[David Schwab]

David, that picture is amazing! I love it.. that bass, I bet it roared! Look at all the knobs! You still have it?

I do! St that time it has a Carvin humbucker at the neck, and a Hi-A pickup at the bridge. A bit later I added a DiMarzio Model P between them and put the Toaster back into the neck position. Bt I left the larger hole in the pickguard and made aluminum brackets so I could get the toaster closer to the strings.

Here's a very funny 70s photo of the bass:



I started doing a lot of work to it after that. I wanted to make it like a 4004 Rick, although they weren't out yet, but it was the same idea. So I filled in all the cavities, and put a maple top on it. I also made it a lined fretless. I never finished the work and it's been in tat state ever since. I'm going to finish it soon. My other bass got painted burgundy mist metal flake, and gor the Hi-A from the first bass and then later a Gibson mudbucker at the neck.

Here's the two basses as they are today. I'm going to restore the purple bass and make it Jetglo.

[rjb]

Or better yet, an acoustic guitar! Then you don't have to worry about knobs and tones and stuff.

Until you need to amplify it.
In a former life, I used to produce folk music concerts.
You'd be surprised how much gear some acoustic bands "require", compared to a typical rock and roll setup.

Later,
-rb