Two Humbuckers with a 5-way Switch

[CaptainChoptastic]

Hi,

So, in a further quandry before I fit my new set of Bare Knuckle Nailbombs to my Ibanez RG2620:

In the original setup of the Ibanez, it has two humbuckers and a 5-way switch which gives, from front to back:
1. Neck humbucker series
2. Neck humbucker parallel
3. Both humbuckers series
4. Inner coils split/parallel
5. Bridge humbucker series

I'd like to keep as much of this versatility as possible with the new pickups, although I don't find the neck in parallel setting too inspiring (but this might change with the Nailbombs!), but the inner-coils give a lovely funk vibe!

OK, so why don't I just wire the new pickups exactly the same way as the old ones? Well the original DiMarzio/IBZs have two rows of hex-bolt pole pieces, whereas the Nailbombs have one row of slugs and one row of screws. If I fit them the traditional Gibson way - with the screws outwards - I'm going to lose hum-cancelling on the inner-coils option (the screw bobbins of both pickups are the same polarity, so no RWRP). If I mount both pickups with the screw coils towards the bridge, I'll get hum-cancelling in all positions again, but the inner-coils will now have one slug-coil and one-screw coil involved. Plus the neck HB will now be reversed from the "traditional" position - if the Nailbombs have asymmetric windings (and I'll check this with Bare Knuckle), then I might be affecting the tone.

Unfortunately I'm not in a position to experiment, as I'm going to have to do a bit of drilling to the pickup cavities in order for the Nailbombs' screw pole-pieces, which protrude from the bottom of the base-plate, to have enough room. I don't really want to go drilling lots of holes in my guitar unnecessarily.

So, any suggestions? Either for keeping the current switching options, or for other interesting ones that I may not have considered, that provide for a good range of sounds?

I realise that some of my concerns are a tad on the cosmetic side or allow for a massive amount of subjectivity, but any suggestions gratefully accepted.

Thanks,
Si

[zenguitar]

OK... first of all here's the link to the RG2620 schematic. It took a little searching, but I found the b*gger

My instinct is that you should just install your Bare Knuckles the traditional Gibson way and all should be fine. But I really don't know how the original IBZ's are wound so I can't be certain.

However, I am pretty confident that if you send a question to Bare Knuckle and include this schematic they will be able to work out whether you can wire your pick-ups as is, or whether they need to perhaps replace one of the Nailbombs with a reverse wound one.

Andy

[CaptainChoptastic]

Hi again Andy.

I feel really guilty now, as I found that schematic a day or two ago on the DiMarzio website. I didn't want to go bogging down my already wordy post with lots of attachments.

I did a little experiment with the DiMarzios and the polarities run - from neck to bridge across the two pickups' four coils - N S N S. Or maybe S N S N. That bit's not important. What is is that I'm pretty sure all positions were hum-cancelling (the strings are off this now), which implies that the inner coils were opposite windings as well as opposite polarities.

If I install the Bare Knuckles in the traditional Gibson manner, the poles will run - N S S N. Or the other way round. So I definitely won't be getting hum-cancelling on the inner coils.

I suppose the question is, does this really matter? Apart from a bit of hum, it's not going to materially affect the tone, is it? Or I could wire things so the inner coil of the neck pickup sits in parallel with the outer coil of the bridge. Again, there's probably no issue with having one slug- and one screw-coil in this sort of split, is there? Perhaps just a slightly more toppy sound?

I'm probably really overthinking all of this, but I'll run the same questions past Bare Knuckles too.

One last thing (isn't there always with me and Columbo? ). As I'm drilling small holes into each pickup cavity to allow clearance for the back of the screw pole-pieces, should I be looking to finish these with a coat of conductive paint? I'm not sure if the cavities are already shielded in this manner - they're painted a silver-ish colour, but then so is the rest of the guitar!

Cheers,
Si

[zenguitar]

No need to feel guilty Si, since I joined the forums tracking down pdf's has become a hobby of mine

The schematic isn't totally clear, it appears that the black and white connections from the bridge pickup are linked to the same terminal on the 5-way.

Standard DiMarzio wiring has the north polarity coil with red and black and the south polarity coil with green and white. Red and white hot, green and black ground. I was going to suggest you checked the magnetic polarity, but you beat me to it, one of those pick-ups is definitely reverse polarity. So don't worry, you really aren't over thinking matters.

The wiring diagram seems to show the 4th position with the two inner coils as series wired. To keep it humbucking in that position you would need to rotate one of the pick-ups from the standard Gibson arrangement. And that would also retain the N-S N-S pole arrangement from the standard pick-ups. So, with a little further thought, that would be how I would go. I wouldn't worry overmuch about the difference between the slug and screw coils. Give it a try and see how you like the sounds.

As for the paint in the cavities, it's probably not conductive. Generally, the bodies are machined fully and then move on to the spray booth for painting. But if you want to check, just use a multimeter to check the paint for conductivity. For the neatest possible job I would use a router with a template following bit (with a top bearing). Use that to follow the edge of the existing cavity and you can control the depth very accurately.

How does that all sound?

Andy

[CaptainChoptastic]

No need to feel guilty Si, since I joined the forums tracking down pdf's has become a hobby of mine

Well - I suppose everybody's got to have one...

The schematic isn't totally clear, it appears that the black and white connections from the bridge pickup are linked to the same terminal on the 5-way.

No, it's not. It's not even particularly clear which pickup is which, but from checking how they look on the guitar, I'd say the top one is the neck. So that's the bridge pickup that has the black and white going to the 5th connection (l-r) of the switch. My guess is that this connection gets earthed in the 4th position, meaning only the coil that has its other end to hot is voiced. Otherwise, no connection puts both bridge coils in series for full humbucking.

Standard DiMarzio wiring has the north polarity coil with red and black and the south polarity coil with green and white. Red and white hot, green and black ground.

Actually, there's a really handy Humbucker Colour Code Conversion Chart over at the Bare Knuckle website (sorry if I've spoilt your fun by sniffing that out for you!). Interesting to note that none of the major pickup manufacturers can agree on a simple colour code!

The wiring diagram seems to show the 4th position with the two inner coils as series wired.

Definitely in parallel, I think. It has that hollow Strat tone, so it has to be, right? Like you say the diagram's a bit of a nightmare to follow...

To keep it humbucking in that position you would need to rotate one of the pick-ups from the standard Gibson arrangement. And that would also retain the N-S N-S pole arrangement from the standard pick-ups. So, with a little further thought, that would be how I would go. I wouldn't worry overmuch about the difference between the slug and screw coils. Give it a try and see how you like the sounds.

I think the only thing that puts me off with that is the aesthetic of it. When I started playing - way back when - I used to think that LPs looked "boss-eyed", now it seems the norm. I've sent an email to the guys at Bare Knuckle (who've been great so far, BTW), checking that rotating that pickup won't affect the sound too much.

As for the paint in the cavities, it's probably not conductive. Generally, the bodies are machined fully and then move on to the spray booth for painting. But if you want to check, just use a multimeter to check the paint for conductivity.

D'oh! Yeah, that would work, wouldn't it? Especially considering that I've just scored a continuity meter!

For the neatest possible job I would use a router with a template following bit (with a top bearing). Use that to follow the edge of the existing cavity and you can control the depth very accurately.

How does that all sound?

Terrifying! I was going to go for a much more DIY approach! The way the pickup cavities currently are, they've got a stepped bottom to them: where the mounting tags sit is a good 5mm deeper than the bit that sits under the base-plate. There's a diagonal groove through this section to allow for the pickup's cable to be routed across the cavity if the pickup is mounted with the cable exit to the top (i.e. the traditional Gibson way).

My plan was to make a template of the pickup's footprint, mark in the position of the screw pole-pieces, then drop this into the cavity and use something like a bradawl to mark out the drilling spots. Then I was going to take a wood-bit that was just a tad wider than the screw-ends, stick a bit of insulating table round it a few mil from the end to mark my depth, and go at it with my black and decker!

I think I need only drill down to a depth of 5mm or so, so being super-perpendicular isn't going to be a massive requirement.

Also, as this is an Ibanez RG, with it's spring cavity and trem back-rout, there's not a whole lot of wood there to start with, and I'd like to keep as much as possible in order to give the pickups something to resonate with! Hence me wanting to make sure I get the orientation of my pickups right the first time, rather than have to go back in and drill some more holes at a later date.

Does that sound like a recipe for disaster?

Thanks,
Si

[zenguitar]

Yep, I know that link and many similar

And as for the two inner coils... I don't know how it sounds, but I am using the colour coding on the schematic to infer it is series not parallel. The hollow strat tone isn't really the difference between series and parallel, it's the comb filtering due to the gap between the coils. And besides, if you assume the colour coding is right and it is series, everything else falls into place neatly. Occam's razer

As for the drilling/routing choice... Mine is a LOT simpler provided you have the tools/bits. And even if I was using a drill with a depth stop, I'd use a hand held router plane to tidy up the bottom of the cavity. Careful and accurate measuring will establish whether or not you have enough wood there to use the router. But all other things being equal, it will do a neater and more accurate job. But the bottom line is simple, use whatever tools and method you are comfortable with.

Andy

[CaptainChoptastic]

Unfortunately this saga rumbles on. I thought I was done last week when I finally got the pickups soldered in place, but now another issue has cropped up.

First a bit of back-tracking: having emailed Bare Knuckle and sent them some pics of the pickups, apparently the pole-piece screws they were shipped with were longer than they should have been. They shipped out a set of shorter screws to me - ones that only come through the pickup base plate by about 2 or 3mm - and Hey Presto: no further routing/drilling required!

So, I got out my soldering iron and hooked up the pickups as per the diagram I got from the Bare Knuckle site, with the same switching options as the original set. Possibly not the neatest soldering job I've ever done, but it seems to be OK.

Now my problem is this: because the Bare Knuckle pickups are less deep that the DiMarzios they're replacing, the mounting screws don't go far enough into the body of the guitar to hold them in place - they just pop out under the tension of the foam blocks underneath. If I screw them in far enough to hold, then the pickups end up way too far from the strings (action is just about right on the guitar), which doesn't appear to be doing nice things to the tone (a bit lacking in top end, I think).

So I think I've got a few options, but I'm not sure which is best, and each seems to come with its own caveats:

1) Get some longer screws: Easier said than done, it would appear. Having spend some time yesterday browsing B&Q's "Wall of Nails and Screws", I can't find anything similar. The existing screws are roughly 1.5mm x 15mm woodscrews, so if I got something the same diameter but about 20mm long, that should do the trick, but only if I could find some!
2) Get some fatter screws: It's entirely possible that my removing and replacing of screws has bored out the screw-holes a bit. Fatter screws should then have more grip, but would also require that I drill out the mounting holes on the pickups, which way well mean having to unsolder them, and soldering them in place the first time around was pain-in-the-bum enough.
3) Fit some pickup surrounds: I was beginning to think that this was a winner, but on checking the guitar again, there's hardly any clearance between the neck-most coil and the end of the neck/fretboard. In fact, the end of the neck forms one wall of the neck pickup cavity. I just think this is just too tight a fit to even try.
4) "Back mount" the pickups: I've got a feeling that I've seen this done in the past on some sort of superstrat type thing. Possibly one of the more rawk-style Hamers. The idea is to take the mounting screws that came with the new pickups (i.e. those intended to work with a pickup surround) and drill holes for them clear through to the back of the body. Then, on the back of these holes, I drill a small countersink for the heads of these screws. Therefore, the screws are loaded from the back of the guitar, and thread into the base-plate from underneath. Foam blocks or the usual springs between the base-plate and the cavity floor take care of making sure that the pickups stay at the right height.

Which of these options makes the most sense? And if I need extra hardware to implement it, where can I get that, as I think I've tried all the obvious places?

Thanks,
Si

[Findo]

I've been in a similar situation when replacing pickups and in my opinion getting longer screws is (by far) your best bet. Ideally you should also fill the original holes first then re-drill (if they have been at all stripped by the shorter screws pulling out.) if you can't find exactly 20mm you could get something longer (1"?)and cut/grind them down.

you may also want to resize the foam if you find you need to use excessive force to screw the new pups down to the right height (or vice versa).

good luck

[zenguitar]

Longer screws, but do the calculations/measuring and make sure they don't go through the back of the guitar

If you have any doubts about the existing holes after removing and replacing the current screws a few times, it's definitely worth plugging and drill again. But the same warning to take care that you don't drill through the back.

Andy

[CaptainChoptastic]

Thanks guys,

Yes, longer screws would be the simplest option, if only I could find some that were even vaguely suitable. 20mm is a bit of a guestimate, so 18mm might be suitable as wood (titter!) 1 inch or their various old money/new money equivalents in that sort of range.

The more critical dimension is the diameter/gauge. As I've said, the current screws look to be 1.5mm-ish which is gauge #0, give or take (assuming my conversion sources are correct), but a #1 might do. It might make sense to go a bit bigger on the diameter, drill out the base-plate a bit, and avoid the need for plugging the holes. Maybe???

I think I've tried all the obvious sources for screws, and quite a few of the less obvious ones, and I'm drawing a blank for screws both that narrow and that long. Any suggestions of where to look?

As for plugging hole, if I need to go down that route, can you give me a summary of how I go about that?

This is beginning to look like a job for a pro, so I might just have to bite the bullet on this one, and get someone to sort this out and maybe give the guitar a bit of a once-over while they're at it. Unfortunately, I think I'm pretty close to getting this done, so it's a bit of a shame to part with cash just to get someone to "finish off" what I've started... I'm tempted to have one last stab before calling it a day though!

Cheers,
Si

[Findo]

of course the other thing you could do is to glue or screw (the latter being more reversible) a strip of wood (say 6mm thick) into the bottom of the pickup cavity to effectively make it shallower. You could then drill and screw into this using the original screws.

I'd start with a rectangle that covers the length x width of the pickup cavity and then trim away the corners and any areas stopping it slotting in until you get a good fit that you can push flat to the base of the cavity.

just an idea, see what Zen say before you do anything permanent! and I'm sure longer screws is the best option - if you can find any!

[. . . Delete This User . . .]

note 18 mm is about 3/4 of an inch, 1 inch is a fair bit longer....

you can usually find some self tapping screws small enough in diameter , with flat faced heads (not countersunk) at decent DIY stores... if you look in the right places....

or you can order the right sort of screw from somewhere like Rainbow products, or Axesrus.