aggravated_alien Posted August 3, 2010 Report Posted August 3, 2010 I have followed the Seymour Duncan Les Paul wiring diagram. How ever the is a very loud hum the goes away when I touch the strings, bridge, tailpiece , metal ring of toggle switch and the jack of guitar cable as well. when I do this how ever it kills all the sound. I would also like the mention that I wound the humbucker pickups for this guitar, these are my first. Both of them work when connected straight to the jack and I have a reading on the multimeter for both of them. when I wired of them up I got the wires mixed up I am not sure what colors are what but as I said before the both worked with no hum when connected staight to the output jack I am pulling my hair out any idea what's wrong. Quote
Samba Pa Ti Posted August 3, 2010 Report Posted August 3, 2010 check the pots work, it sounds like the ground is shorted out as when you touch the strings you are becomming the ground and the hum goes away. Quote
aggravated_alien Posted August 4, 2010 Author Report Posted August 4, 2010 Potentiometers work I tested with multimeter and I can also turn the hum up or down. Quote
borge Posted August 4, 2010 Report Posted August 4, 2010 plug a lead in and test & record resistances (taking note of ohms range, some readings will be 1-2 Ohms, some will be 5-15kiloOhms ) of: 1 lead sleeve to machineheads 2 lead tip to machineheads 3 lead sleeve to pup cover or if uncovered, the baseplate. 4 lead tip to pup cover or if uncovered, the baseplate. 5 lead tip to sleeve, volumes wide open-should give resistance close to your pup readings when individual pups are selected (via pup switch), resistance should decrease to close to zero as you turn the corresponding volume down. Sounds to me like you have signal-earth reversed, so when you touch what should be earthed you are touching signal which you are then earthing via your bodys earth connection. I'm just speculating, I've never a signal-earth reversal problem, whether my theory holds water depends on how well your body is earthed. Quote
aggravated_alien Posted August 4, 2010 Author Report Posted August 4, 2010 I am using 4 conductor wiring if I measure from the start lug to the tip of the output jack I get a good reading. I don't know the color codes I got them mixed up when I assembled the humbucker could this be the reason maybe I have the colors wired in the wrong places. Quote
borge Posted August 4, 2010 Report Posted August 4, 2010 Ok, thats not good.. I'll explain what they should be, that may help: 1 lead sleeve to machineheads-close to zero, proves the strings are earthed. 2 lead tip to machineheads-close to the pup resistance (5k-20k) (or the pup pair in parallel if both pups are selected)-proves pup/s in circuit and strings are earthed 3 lead sleeve to pup cover or if uncovered, the baseplate.-close to zero, proves pup cover is earthed. 4 lead tip to pup covers or if uncovered, the baseplate. close to the pup resistance (or the pup pair in parallel if both pups are selected)-proves pup/s in circuit and cover/s are earthed 5 lead tip to sleeve, volumes wide open-should give resistance close to your pup readings when individual pups are selected (via pup switch), resistance should decrease to close to zero as you turn the corresponding volume down. - proves volume pots are doing what they should. so from here, eliminate faulty lead: 6 Unplug lead, test tip to sleeve-should be in the MegaOhm range-proves lead isnt shorted, 7 test tip to tip-should be close to zero, proves signal conductor is good 8 test sleeve to sleeve-should be close to zero, proves earth/screen conductor is good. If the lead is good, you either did all the tests with the volume/s on 0 or theres a short to earth somewhere, but that still wouldn't explain the buzzing hmmm 9 Ignoring the loud hum, is the guitars output volume at a normal level? 10 do you have an auto ranging MM or manual? depending on your MM you could get zero for all tests if you had it set to the wrong range... Quote
aggravated_alien Posted August 4, 2010 Author Report Posted August 4, 2010 I did all the tests the pickups aren't in the circuit. everything else is fine. Now what. Quote
borge Posted August 4, 2010 Report Posted August 4, 2010 You mean you redid the tests? what were the results? (answers next to corresponding numbers 1-10 would be good) If you didn't redo the tests, "0 for everything" proves only that you have a signal-earth short and says nothing of the pickups status. I am using 4 conductor wiring if I measure from the start lug to the tip of the output jack I get a good reading. Whats "the start lug"? I don't know the color codes I got them mixed up when I assembled the humbucker could this be the reason maybe I have the colors wired in the wrong places. Check this thread to sort that out: http://projectguitar.ibforums.com/index.php?showtopic=43902 Quote
Suek Posted November 16, 2010 Report Posted November 16, 2010 Did you get this fixed? Sometimes it's as simple as you input wire where the jack is. I had one guitar like that. Sometimes it gets tugged on too much when your working on other wiring. I know I did it. lol Quote
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