Mid postion volume drop in LP

[ShannonH]

Hey guys,
I have hunted for an answer to this, and I may be searching for the wrong terms, but I have a wiring question that is driving me crazy.

When I switch my Les Paul to the middle position, there is a volume drop that goes away when you lower the volume. My thoughts were that it is either that
1.) Freqs are cancelling each other out until the volume is lowered (volume cuts some highs) like crossing speaker paths will do

or 2.) that is has something with the freaky way all the pots on a les paul interact.

I have an ibanez art series with an Vol-tone-tone and get no drop in the middle position.

It's driving me nuts, because when I do a demo, people love the pickups until they hit that middle position. ("Are your pickups out of phase, Dude?")

Help!

Thanks,
Shannon

PS: I tried to move this to general electronic q's, sorry about the incorrect placement of the thread.

[pdf64]

Are you dead sure that your pickups are in-phase? Just as a reality check, can you reverse one of them easily to see if the problem goes away?
Are both pickups the same, or at least similar impedance?

[earthtonesaudio]

GuitarNuts.com - Typical Gibson-style Guitar Wiring

Scroll down to the sections in the white boxes. You can probably add one or two resistors to cure it.

[David Schwab]

Does the tone get thinner, i.e. do you lose low end, in the middle, or just lower in volume? If you are losing low end, or they sound real hollow, the pickups are out-of-phase. Turning one volume down slightly makes it sound fuller.

I have found that different combinations of pickups sometimes seem weaker in the middle. It seems to be either a loss of mids, or just one pickup loading down the other, if one is wound a lot hotter.

I didn't like the tone of both pickups on my Les Paul. But when I changed the lead pickup to something hotter (an old SDHB), the middle position was better.

[Jag]

To a degree, that's normal, I don't have the time right now to go into detailed explaination of why. With some pickup combinations, this is more pronounced. If both pickups a fairly closely matched, with the coils of each pickup closely matched, it will be more obvious than pickups/coils that are not matched. The difference should not be super huge however.

The most obvious question is, are you sure they are not out of phase? Do you have any special wiring schem, maybe coil splits, that could be cross connecting with both pickups active?

[Jag]

The link posted by Earthtonesaudio explains it failrly well.

[Mark Hammer]

If the volume increases when one of the pickups is turned down a bit, that is a dead giveaway that they were inadvertently wired up out of phase with respect to each other.

Now, that is not necessarily a "mistake", since it is clear from the post that this permits one to adjust balance to achieve other tones, and reduce the cancellation effect. However, if one wants classic LP tone with both volumes up and both pickups on, better flip those leads around on one of the pickups.

[ShannonH]

Are you dead sure that your pickups are in-phase? Just as a reality check, can you reverse one of them easily to see if the problem goes away?
Are both pickups the same, or at least similar impedance?

I am very sure. I have a note in my wiring station "Black starts, white finishes". I will try reversing them though

Does the tone get thinner, i.e. do you lose low end, in the middle, or just lower in volume? If you are losing low end, or they sound real hollow, the pickups are out-of-phase. Turning one volume down slightly makes it sound fuller.

I have found that different combinations of pickups sometimes seem weaker in the middle. It seems to be either a loss of mids, or just one pickup loading down the other, if one is wound a lot hotter.

It gets mostly quieter. Not hollow per se. I have had single out of phase on my strat, and that's not the sound I'm getting. The PU's are 8.4 bridge, 7.6 neck.


To be clear, if I was wiring out of phase, I would have connected start to start on one pickup, and end to end on the other? I will do the switch to check, but I have my doubts. Of course, late night wiring could have caused the problem.

Thanks!

[ShannonH]

GuitarNuts.com - Typical Gibson-style Guitar Wiring

Scroll down to the sections in the white boxes. You can probably add one or two resistors to cure it.

I think this is the issue. I will rewire to the listed diagram and see...

duncan has that diagram on their site too

Peace

[David Schwab]

To be clear, if I was wiring out of phase, I would have connected start to start on one pickup, and end to end on the other? I will do the switch to check, but I have my doubts. Of course, late night wiring could have caused the problem.

Thanks!

It doesn't always sound hollow. I had this happen on a bass with some test pickups, and it wasn't that obvious because each pickup sounded different. But it seemed weak. Switching the wires showed it was indeed out of phase.

Sometimes the magnet will be backwards in a pickup and that will put it out of phase.

It's real quick to reverse the two wires (unless you are using old fashioned coax) to see if it's out. You will know it right away.

I would try that before adding resistors.

[the great waldo]

Hi ShannonH

If you have access to an analog multimeter connect a lead to the guitar output and connect the meter probes to the end of the jack plug making sure the volume pots are full open and using the dc resistance setting on the meter 20k ohms should be the right setting, if you move a large iron object like a screwdriver or a set of pliers ( over the pickup ) sorry missed that first time round )the meter will deflect in one direction. Both pickups should have the meter needle swinging the same way if they are both in phase.

Good luck

Andrew

[Jag]

COOL!!! I didn't know that!

Makes sense though.

[ShannonH]

It does sound sort of hollow, with a kind of Skynrd vibe. The wiring is fine, so it's probably phase. That's pretty embarrassing. I'll switch the wires tonight and see.

Now to find an analog meter...

[David Schwab]

Now to find an analog meter...

17-Range Analog Multimeter - RadioShack.com

[jason lollar]

might as well try it with a digital meter while you wait for an analog- you have to be slower about moving he steel and try it a couple times to be sure you get a consistant reading but my digital will read phase. Mines just a UEI DM383B so its decent but nothing special.

[David Schwab]

It does sound sort of hollow, with a kind of Skynrd vibe. The wiring is fine, so it's probably phase. That's pretty embarrassing. I'll switch the wires tonight and see.

Now to find an analog meter...

If you wire up both pickups the same way, they should be working in phase with each other.

Just make note of how you wire them up, and do it the same way for both pickups. This includes magnet orientation.

I made a little chart to follow in case I have a brain cramp and forget.

[ShannonH]

I made a little chart to follow in case I have a brain cramp and forget.

Me too, but after taking care of the little ones and then wiring after midnite, schtuff happens! Thanks so much for all the great responses!

[ShannonH]

the bridge pickup, careful steuthing, or blind, do da luck. take your pick. That's irritating, but it was one of my first winds, so I may have to absolve myself.

Peace

[David Schwab]

Was it out of phase? You know, it can be either one. There isn't a right or wrong polarity if it's not in comparison to another pickup. Otherwise it's kind of arbitrary.

As long as you make your pickups so the polarity can be easily swapped at the wire, which isn't possible with 2 conductor vintage style cable, any one can get two different brands of pickups to get along.

[ShannonH]

Was it out of phase? You know, it can be either one. There isn't a right or wrong polarity if it's not in comparison to another pickup. Otherwise it's kind of arbitrary.

As long as you make your pickups so the polarity can be easily swapped at the wire, which isn't possible with 2 conductor vintage style cable, any one can get two different brands of pickups to get along.

I made them with pushup vintage style (braided on the outside). I may change that after this experience. It is out of phase, just a simple wire inversion under the cover. grrrr.