Gibson Dirty Fingers pickup problem - out of phase no matter what. Help!

simonhpieman

So, I'm the worst guy for switching pickups/electronics but I have SOME knowledge.

I've an Epi Riviera (80s Matsumoku) that has a replaced bridge pickup. I didn't know what it was until I did some work on it recently and found the PAT number on the bottom. It seems to be an original Gibson Dirty Finger(s?!).

The problem I have is that it always sounded out of phase in the middle position. I really like the middle position on semis so when I first took it to a tech (for a fret dress and a few other bits) I asked him to put it back to normal. I forget why he never actually did this but when I went back to collect it it seemed to boil down to the fact that he hadn't been bothered enough to do it. (Didn't use HIM again...)

ANYWAY... I noticed the pickup had been mounted upside down as the little holes in the bobbin were in the wrong place. So when I did a string change I thought I'd swap it up the other way and that would put it back in phase. Right?

Wrong. It's still out of phase. I'm not about to dive in there as I haven't got a clue what I'm doing and can't solder to save my life but does this have anything to do with the Dirty Fingers having screws in both coils? Has it just been wired wrong? Why didn't flipping it sort the phase issue?

Anyone who has any idea about this sort of thing?

simonhpieman

PS: I know how ridiculous the idea of having the world's highest gain pickup in a semi is. It was already in there when I got it, honest, gov!

simonhpieman

Here's a pic

http://imgur.com/gallery/zOlvpWV

Sesh

Flipping a pickup does nothing. Whether two pickups are in or out of phase is to do with magnet orientation and the direction the coils are wound. I'm afraid it will need a few wires swapped, so if you are not keen on soldering then find someone who understands pickups and soldering. i.e. find a guitar tech who can be bothered.

simonhpieman

@Sesh can you clarify that flipping a HUMBUCKER pickup does nothing? I had a Jaguar and installed it's single coil pickup the wrong way up (first and last time I tried that!) and seem to recall flipping it sorted it out.

Either way, thanks for that. Appreciate it!

Sesh

I'm by no means an expert, but rotating a pickup doesn't change the phasing as far as I know.

mart

Yep, rotating any pickup will not change the phase. The phase is an electromagnetic thing, so can be changed by changing the wiring or the magnet (but not both as that will cancel out), not by physical rotation of the whole pickup.

ICBM

simonhpieman said:

ANYWAY... I noticed the pickup had been mounted upside down as the little holes in the bobbin were in the wrong place. So when I did a string change I thought I'd swap it up the other way and that would put it back in phase. Right?

Wrong. It's still out of phase. I'm not about to dive in there as I haven't got a clue what I'm doing and can't solder to save my life but does this have anything to do with the Dirty Fingers having screws in both coils? Has it just been wired wrong? Why didn't flipping it sort the phase issue?

You're not alone. Whoever miswired Peter Green's Les Paul neck pickup presumably thought that turning it round would fix it too... it didn't, although the guitar then sounded quite good .

There are only two ways to reverse the phase of a pickup... reversing the magnet - not recommended on a Dirty Fingers, it has *three* magnets! - or reconnecting the coil the other way round. So you need to get at the control end of the wire, and swap the thin wires that are connected to the volume pot terminal and to the casing - not the shield wire which should remain connected to the casing.

If it only has a single-core cable with an outer braided shield - I can't remember if any Dirty Fingers versions do - then you have a major problem, and it's probably easier to reverse the neck pickup instead which will achieve the same thing... phase is relative, not absolute.

Funkfingers

The DF humbucker that I had in 1982 was single con + braid. 

Senility means that I cannot recall whether the original DF had a single bar magnet or three of them - a bit like the Gibson Iommi humbucker.

ICBM

Funkfingers said:

The DF humbucker that I had in 1982 was single con + braid. 

Senility means that I cannot recall whether the original DF had a single bar magnet or three of them - a bit like the Gibson Iommi humbucker.

All the ones I've seen have the three magnets. I thought I'd seen some with the braided cable too, although I've definitely also seen them with 4-conductor.

Funkfingers

THINKS: The old Gibson DF is a high output pickup of some monetary value.

What pickup is currently in the neck position?

It might be wiser to correct the phase issue by flipping the magnet(s) or altering either the output cables for the neck/Rhythm pickup. 

If the Riviera has a plastic covered P90, the job requires a maximum of three screwdrivers and, if you wish, a permanent marker pen.

ICBM

Funkfingers said:

THINKS: The old Gibson DF is a high output pickup of some monetary value.

What pickup is currently in the neck position?

It might be wiser to correct the phase issue by flipping the magnet(s) or altering either the output cables for the neck/Rhythm pickup. 

If the Riviera has a plastic covered P90, the job requires a maximum of three screwdrivers and, if you wish, a permanent marker pen.

It's not a P90, it's a metal-covered humbucker.

Funkfingers

Oh, well. That’s me out.

FelineGuitars

If you are in London, we can sort it for you (we're in Croydon)

ICBM

FelineGuitars said:

If you are in London, we can sort it for you (we're in Croydon)

I would advise taking @FelineGuitars up on this offer - I don't think it's a straightforward fix for the inexperienced. This may explain why the first tech didn't want to do it... and possibly why he didn't want to say why.

simonhpieman

Wow, thanks everyone!

Found a pic of the back of the pickup - it's braided.

http://imgur.com/gallery/UXVellM

Someone'll probably tell me it's not a Dirty Fingers now, too! 

That said, this guitar has been modded to within an inch of it's life - I'm pretty sure it was left handed once (not sure if it's a left handed guitar that was converted to right or a right handed guitar that was converted to left and back again). It came set up right handed but had holes drilled in the top for all the controls in left hand positions. Had to have the holes dowelled. Crazy. I got it from a touring hire place for a keen price so I wasn't too worried (work experience kid/apatehetic millenial on the staff had listed it as a 339 on eBay) but it had clearly had a life.

Anyway, turns out the DF is wired directly to another wire, a plastic-coated thinner one, which I assume is the guitar's orignal wire which leads off to the pot(s? What do I know).

I THINK the neck pickup is the original MMK but I couldn't get it out of the cavity last time I had the strings off. May be easier to reverse that as stated.

@FelineGuitars I may take you up on that offer. I'm near Farnham these days but may come by next time I'm up London which will be soon. Thanks!

Funkfingers

Link no workee.

A genuine forty years old Gibson DF humbucker is surprisingly weighty and should have a strip of screening foil around the outside edge.

The important detail is whether the output cable is single con + braid or multiple conductors + screen? The latter will be far easier to rewire in the correct phase.



On a slight tangent, Andy Summers' favourite ES-335 has evidence of a right-to-left-and-back-again conversion. I cannot remember whether Gibson replicated this on the signature model.

simonhpieman

Sorry, fixed the link.

Cool fact about Andy Summers, maybe it was his!

Oh, and any screening foil is long gone. Surrounded by some starting to peel electrical tape, now!

ICBM

simonhpieman said:

Oh, and any screening foil is long gone. Surrounded by some starting to peel electrical tape, now!

The foil should be under the tape, unless both have been removed and new tape put on. The foil is copper and looks quite like the normal coil wire.

If the foil *has* been removed, swapping the coil connections at the pickup is probably the easiest way.

Tat2dstesh

I don't know if I'm crazy for doing it but when I wire my guitars I always do the middles out of phase sound as I use it quite a bit for weird bits in songs and it's got a great single coil vibe thing going which always sounds weird in a Gibson guitar