Help on a complex wiring plan -Gib LP Professional

Hello and welcome to GN2!!!

This is a very interesting setup, to clear a few things up how many position do the rotary and blade switch have??? And what style switch are you using for the phase??? Are those 'diodes' l see on that volume pot??? whats their purpose there??? ls this dual humbuckers or p-90's???

Reguardless thats a hellova setup.

+1 for posting the schematics and gutshots they've inspired the lil' hamster in my head. ;D

Thanks for the reply !


Well the decade switch (rotary) is a strange thing, I'll try doing a different reply about it.
For the Tone selector (blade switch), there is 3 positions, labeled as 1 2 3 on the outside of the guitar.

Its an On Off type of thing :



It must be my lack of drawing skill that confuse you
Theres just a pot, some resistance and a cap.

It's actually dual low impedance pickups. My guitar is a strange one, straight out of Les Paul's twisted brain ;D

Thanks for you help

You reply is very technical for me so I'll take it slow, one by one



I remember from looking at other pictures that the phase switch on the schematic is different then the way it's hooked up in a real guitar. From the photos, i could see the red wire coming out from the lower left lug to the "patch bay" lug #5. From that same lug, another red wire goes back up to the pickup selector. Does that work, or is there an issue with it connecting on the patch bay ?



For the ground, the lug #2 acts as one(same for #7), at least I think so, as seen in this photo :



Close up of my phase switch (most of the wiring in my guitar is not ok at the moment but this part looks ok compared to other pictures I've seen, minus the 2 wires coming from the pickup, for obvious reasons) :


Let me know if it's ok.

That also was an "adjustement" I did because of real life photos from other guitar, as seen here :



Can it affect the sound if it goes to the tone switch log #7 first as in the pictures ? I still have difficulties sometimes picturing the relation between the plan and the effect on the sound it will produce.

Thanks a lot for your help

Yes, my friend tried to explain that to me. I know there are still a couple times on my plan i forgot to hump over



Yeah i did mine pictured from the top. Similar to the picture i posted as the reenactment. I'll see if I got it worng depending what you say about that one.


Well I think i covered it all. Time to go eat. Thanks for you help guys.

pemorin-

I was simply comparing the Gibby schematic to your diagram; I did not attempt to compare the wiring in the pictures to either your drawing or theirs.

Whether the wiring in either your guitar and/or the other one you photographed matches up to the schematic or not is an open question. First, there may have been alternate versions of the guitar from Gibson. Second, the schematic can be translated in several different ways to an actual wiring plan or diagram; the wiring in the guitar may be "equivalent" to, but not exactly equal to, the schematic. Finally, someone may have screwed with it before you got it.

Since I gather from your post that it wasn't working when you got it, and was in fact missing some parts, option #3 is looking good . . .

I can't tell much of anything from your pictures. They're good photos, but there's enough going on that it's hard to trace anything out. And your disambiguation of the switch still has me puzzled as to which wires are connected where.

But there are a few basics we can look at here.

First, Gibson's schematic will do what it it supposed to do, and if that comports with what you want it to do, then wiring it according to the schematic is your best bet.

The basic scheme here is the that the bridge pickup goes first to the phase switch, and then from the phase switch to the 3-way switch. The neck pickup goes directly to the 3-way. The bridge pup hot lead attaches to the bridge side of the 3-way; the neck hot to the neck side. Both pickup grounds go to any convenient grounding point (back of a pot is fine).

The center terminal of the 3-way then goes "out" to the rest of the switching and controls. Think in terms of the signal flow so far- each pickup goes to the three-way switch, with the bridge pup being selected for phase (or not) first.

At the three-way switch, a pickup or pickups are selected, and the signal travels on to the "tone network". This network comprises several elements- a bass pot, a treble pot, a "decade switch" and a "tone switch".

Think of it as if it were one big tone control, albeit a complicated one. But the whole shebang could be easily replaced with a single tone pot- simpler but with less variability. The whole "tone network", as I'm calling it, is a module, a discreet piece of the larger design.

After the signal gets bent up some in the tone network, it goes on to the volume pot and then out to the jack.

I hope that wordy description actually helps make it easier to see what's happening here.



Not sure on that, let me study the pix some more.

Ok,

This is the way i see it, let me know if you find a fault.

The tone switch lugs are numbered 1 to 4 on the top row left to right, and 5 to 8 on the bottom row, left to right.

1 and 8 are always active in the flow.

When tone 1 is selected, lugs 2 and 5 are active.
Compared to what jbwid.com says, the way i see it, the decade is bypassed in Tone 1 mode.
So its straight Pickups to 150 resistance and 0.47 cap, then volume then out.


When tone 2 is selected, lugs 3 and 6 are active.
It renders the treble pot, bass pot, decade and pickup selector active.


When tone 3 mode is selected (lug 4 and 7), its just pickup selection and decade before volume and out.


Now, when you read the Gibson Schematic, knowing what lug the tone selector affects, is that what you read too ?

Let me know.

All right, I think at this point I will take that and run !

Maybe the guy just explained it improperly, as even his schematic for Tone 1 seems to not connect the decade with the flow to the output, and on Tone 3, the flow goes directly through the decade to reach the other stuff.

Ok last one : I think in your first reply, you were telling me i should use the clockwise lugs of the pots. This is what seems to be done for volume and bass pots in the other unmodified (afaik) pictures, but not for the tone. Both seem to use the counterclockwise lug.

Now, being a rookie solder flinger (that's what the forum gives me as a title, so it must be true ), I would be tempted to do the same. Can you explain to me the difference that exist between both lugs ?

Thanks a lot for your help, I feel like a 1st grader asking that last question

Well thanks a lot for everything Newey, you've been extremely helpful. I'll be doing the modifications soon, so wish me luck.

If you wish to see my restoration process, I am documenting it over at the My Les Paul forum :
www.mylespaul.com/forums/gibson-les-pauls/99478-my-lp-professional.html

Thanks !