Killatine Posted May 31, 2012 Share Posted May 31, 2012 Hey guys, started a new thread even thought this is kinda related to my other thread, but I need more specific help here. I purchased a "vintage style" electronics kit, most everything is pre-wired, just need to attach the pickup, which I understand, but both the provided wiring diagram and a few others I found online mention grounding to the bridge or tremelo. I found some info online about how to do this, but also they say if they are active or passive it makes a difference. Passive=grounded, active=not. I dont see any existing wire for the ground, but if I understand the diff, active pickups have pre-amp circuitry. I dont think that the P90 has this, but then where is the ground wire? Hmmm. Does anyone know if the P90 needs to be grounded? Thanks in advance Link to comment Share on other sites More sharing options...
stein Posted May 31, 2012 Share Posted May 31, 2012 The ground wire for the guitar itself SHOULD be coming from the bridge or tailpiece. Not so much a "wire" as in a coated wire or cable, but literally in this case a metal wire. It should connect to the back of a pot. The pups, if they are the typical P-90 type with one conductor and a metal shield, the metal shield is both the (-) AND the ground. It should connect to the back of the pot the pup is connected to. IF the pup has 2 wires AND a shield, the (-) wire and the sheild both connect to the same place: back of the pot. It is common for diagrams to not show the grounding. Some do, some don't. The back of all four pots should have a wire connecting them from pot to pot. Normally, it would be the two volume pots with a wire between them, and each tone pot with a wire to the volume pots. The ground wire from the bridge connected to the back of any pot (usually the volume pot though) will make it so the backs off all pots are all connected to ground. IF the guitar has a metal plate that all the pots are threaded though, the metal plate replaces the ground wires connecting the pots, because the shaft of the pots are also connected to the back of the pots due to the way they are made. In that case, you may have the ground wire from the bridge connecting to the plate instead of the back of a pot, and no wires on the back of the pots connecting them. Link to comment Share on other sites More sharing options...
Killatine Posted June 1, 2012 Author Share Posted June 1, 2012 Stien, thx for your reply, I have a single pickup. Below is the diagram I have seen, a few others also show the ground, but this def doesnt exist on my guitar. I have never heard this guitar play, so its not like "it worked fine before". I bought it with the electronics hosed, but they were connected, just, as I said, no ground. I have found someplace where they suggest drilling through to the bridgepost, but how could this guitar have ever worked before if there is no connection to the bridge, which I have removed looking for any wires. Another head scratcher. Link to comment Share on other sites More sharing options...
stein Posted June 1, 2012 Share Posted June 1, 2012 Ah...Lp junior. I see from your other post, your have a '56 junior? Are you sure the electronics aren't origonal? Anyway, back to the subject at hand. If it is a Junior, you might find this ground wire going from the post into the pup cavity instead of from the post to the pots cavity. Again, look for a bare wire. In some cases, the ground wire might have been soldered to the shield of the pup wire. It could have also been soldered to the back of the pup. It could have also just come out into the pup cavity and then fished through from there into the pots cavity and soldered to the back of a pot. I am guessing that if it was soldered to the back of the pup coming from the bridge post, it also continued on through the same hole as the pup wire and was also soldered to the back of the pot. The guitar will still work the same if it has the ground wire or not. What the ground wire does is ground the strings, so when you are playing, your body making contact stops a lot of the hum. That hum that comes and goes when you lift your hand from the strings or bridge-that's what that ground wire does. Link to comment Share on other sites More sharing options...
Killatine Posted June 1, 2012 Author Share Posted June 1, 2012 Yeah, I took the whole thing apart, no ground or a hole the could be used for one, so that bums me out since Ive now read in several places the the P90 is a noisy beast, hence the invention of the humbucker. I dont think the pots are OE due to a very good site on gibson electronics. I guess its alright to put links up, soI will include a few Ive found recently that I think are very informative, including one about hum and grounding This one on hum and grounding This ones on how to identify vintage electronics And for good measure This ones on tuners And this ones on identifying vintage guitars, a really in depth site with alot of info on all typw guitars but Im gonna link you to the Gibson section but he has all kinds of info on fender, gretch, etc Link to comment Share on other sites More sharing options...
Killatine Posted June 2, 2012 Author Share Posted June 2, 2012 Well. took a better look and found the ground wire broken off inside the hole coming from the pickup to the electronics. guess it comes from the bridge stud insert, but I will have to open the hole up a bit to be able to solder on an extension, but at least I found it. Link to comment Share on other sites More sharing options...
tazzboy Posted June 2, 2012 Share Posted June 2, 2012 Some pictures would sure be helpful Link to comment Share on other sites More sharing options...
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