SG riddle

[angelodp]

Hi all, I did a bit of work on a Faded SG a while back. It had the doinky Peter Green thing going, so i flipped the magnet and it was all good, but..... I notice now that I am getting some 'noise' ala single coil-ish on both the next and bridge position, but none in the split position. anyone experienced this and can recommend a remedy. Its a gibson and wired in the vintage mode.

[newey]

It had the doinky Peter Green thing going, so i flipped the magnet and it was all good, but.....

You shouldn't have needed to flip the magnet to put the pups back in phase. Switching the wires would have done the same.

First, ascertain that all 4 coils are in fact operating. But since you indicate the noise affects both pickups when individually selected, I'm leaning more towards the issue being a loose connection somewhere.

[asmith]

I thought he said the pickups were fine individually.

...but none in the split position.

Is that what you mean, Angelo?

Did you make it out-of-phase in the first place, by flipping the magnets? Or did it come to you out-of-phase, in which case it might have been the wires that were the 'wrong' way round from square one.

I wonder if swapping the magnets has had a 'non-hum-canceling' effect when you select both. Perhaps swapping the magnets has changed the way the pickups interact with each other, so that the EMF constructively interferes? After all, you've got two correctly-wound humbuckers, and only one correctly-orientated set of magnets. My physics qualification is coming back to me very slowly, so I don't know for certain whether I'm talking horse-manure or not.

The solution ought to simply be to flip the magnets back in your coils so you're back to square one, and reverse the wiring of the pickup.

If that doesn't work, let's look at something else.

[angelodp]

Both pickups are working fine, except that I notice that i am getting a little hum with either the bridge or neck selected, whereas I get a nice quiet signal in the split pickup position. Much like a two pickup strat except the noise is more subtle. All I did was to reverse the magnet in the bridge pickup to get rid of the peter green tone.

[Yew]

Sqapping the magnet should change the Hum cancelling in the middle position, .. as you still have a coil on either pole..

[newey]

Angelo-

I took you to mean that the pickups weren't really "split" in the middle position, that this was wired as a std SG with both full HBs in the center switch position. If you have a coil split there, then yew's right, that could well be the problem.

Out of phase is out of phase, it doesn't matter what got it there or which way you fix it. The result of flipping the magnet or of switching the wires should be exactly the same.

Hum-cancellation is never 100%, even HBs can make some noise, and depending on windings and the vagaries of an individual set of pickups, you certainly could get more cancellation in the middle position with 2 HBs as compared to either one individually.

The fact that you get the same amount of noise with either HB selected individually would seem to indicate the problem lies outside of the pups themselves- and noise issues can be devilish to track down, and even tougher for others to diagnose at a distance.

I don't have a "smoking gun" I can point you to here, just general principles. I assume you've done the basics- tried different amps, different cables, etc.- to eliminate causes other than this particular guitar.

If so, a double check of your connections is next- starting with the bridge ground and other grounds.

If all else fails, as JA points out on the original Gnutz site, sometimes HBs can benefit from shielding, although it's usually not needed.

Do you know for sure that this noise was not present originally, before you switched the bridge pup magnet around?

[irwired]

I would like to reinforce what Newey said.

My Reverend (2 Hbs) quieted down considerably after some shielding and proper grounding.

A multimeter was instrumental in diagnosing a weak bridge ground. There was high resistance 2-300 ohms before and 5-10 after.

When working with any test equipment, test the equipment first.
I have chased my tail on too many occasions only to find my battery was low or my leads had a problem.

Best of luck

IRW

[angelodp]

Dec 17, 2010 6:35:48 GMT -5 newey said:

Angelo-

I took you to mean that the pickups weren't really "split" in the middle position, that this was wired as a std SG with both full HBs in the center switch position. If you have a coil split there, then yew's right, that could well be the problem.

No coil split, just standard HB's in center position. Maybe I am being too picky as it seems that the consensus is that some noise is possible with HB' as well.

Out of phase is out of phase, it doesn't matter what got it there or which way you fix it. The result of flipping the magnet or of switching the wires should be exactly the same.

I cannot recall why I went for the magnet flip. except that it worked... no Peter Green doinky tone.

Hum-cancellation is never 100%, even HBs can make some noise, and depending on windings and the vagaries of an individual set of pickups, you certainly could get more cancellation in the middle position with 2 HBs as compared to either one individually.

Ok if that's the case then I am just chasing a very subtle bit of noise.

The fact that you get the same amount of noise with either HB selected individually would seem to indicate the problem lies outside of the pups themselves- and noise issues can be devilish to track down, and even tougher for others to diagnose at a distance.

I don't have a "smoking gun" I can point you to here, just general principles. I assume you've done the basics- tried different amps, different cables, etc.- to eliminate causes other than this particular guitar.

If so, a double check of your connections is next- starting with the bridge ground and other grounds.

If all else fails, as JA points out on the original Gnutz site, sometimes HBs can benefit from shielding, although it's usually not needed.

Do you know for sure that this noise was not present originally, before you switched the bridge pup magnet around?

I will do some more testing.

thanks Ange