What have I done wrong??

[Hollowpoint]

I've just finished completely rewiring an old Epi Les Paul Studio with new switch, pots, jack and pickups - an SD Screaming Demon in the bridge and a Dream 90 humbucker sized P90 in the neck position.

My problem is that the Screaming Demon sounds awful - thin and trebley. On top of that the bridge tone knob is acting more like a gain/volume control (though it doesn't completely silence the pickup) than a tone control - I'm assuming these problems are probably related.

I thought the problem could be with the capacitor on the bridge tone pot but I've tried a couple now and though my soldering leaves a bit to be desired, I'm pretty sure it's seated properly.

Anyone have an idea what could be going on?

Here is my wiring diagram



Thanks a lot for any help!

[TmcB]

Go and carefully check over each bit of wiring, make sure you have the right wires from the pickup soldered together. Red and White together, green and bare together grounded, and the black to the lug.
Check all grounding points.
Your tone cap could have been overheated.

[AmpShop]

Thin and trebly could suggest that you're only using one coil - as Tony says, double-check all the pick-up wiring for a start. Perhaps even disconnect the p/u from the circuit and measure with a multimeter.

When you get right down to it, the tone control is a gain control for high frequencies, so perhaps it's working correctly, but the volume control isn't?

My suggestion would be to take a break, come back and look at it with fresh eyes and you'll probably find the fault quicker and easier.

[Hollowpoint]

Thanks guys, I'll have a good look at the pickup wiring when I get home.

[ash]

I'd look for a shorted tone cap and that the red and white wires are joined.

[capt abaham]

should the red and the white be joined instead of grounding the white wire of the SD, if im looking at this correctly
oh same on the other pick up, the cables shouldnt be grounded as far as i know.

only ground the green wire.
use the hot wire to go to a pot
join the remaining wires and tape them so there not going to ground.

[TmcB]

should the red and the white be joined instead of grounding the white wire of the SD, if im looking at this correctly
oh same on the other pick up, the cables shouldnt be grounded as far as i know.

only ground the green wire.
use the hot wire to go to a pot
join the remaining wires and tape them so there not going to ground.

This is almost true, but this probably explains it better;
http://www.seymourduncan.com/support/wi ... h_2v_2t_3w

[ash]

Green and bare to earth. Red and white joined. Black to hot. (SD only)

Green and white to earth would cut one coil and is what several of us suspect is wrong.

[Hollowpoint]

I'm pretty sure I've got the green and bare wire to earth and the red and white joined and taped. Will check to be sure when I get home at 11. Cheers

[capt abaham]

should the red and the white be joined instead of grounding the white wire of the SD, if im looking at this correctly
oh same on the other pick up, the cables shouldnt be grounded as far as i know.

only ground the green wire.
use the hot wire to go to a pot
join the remaining wires and tape them so there not going to ground.

This is almost true, but this probably explains it better;
http://www.seymourduncan.com/support/wi ... h_2v_2t_3w

your first reply nailed it