motherbucker wiring help

[necksnapper]

hello gentlemen, I've been lurking in the shadows for a couple years now and I've finally got a project that I could use some of your expertise on. I've got a gibson sg and recently purchased a Kent Armstrong MB. I would like to wire it with a push/pull pot (maybe more than 1) so I can switch to one bucker instead of all 4 coils (and/or series/parallel switch). I've been looking @ diagrams for days and I haven't found much on this pu or 3HB diagrams (I realize that's essentially what I have). Could you point me to a diagram or give me a hand with this? I know you guys are excellent @ this kind of stuff. Whereas, it takes me a while to wrap my mind around multiple solders. I'm also open to suggestions. I just don't want to start drilling xtra holes in this particular guitar (I've got several others for that). Any help would be greatly appreciated. And one more thing, I currently have a GFS crunchy rails in the bridge that I'm thinking of moving to the neck. Any thoughts on that? Don't hold your tongue.
Thanks, Rich

[newey]

Necksnapper-

Hello and Welcome!

hello gentlemen, I've been lurking in the shadows for a couple years now

You're Dick Cheney??!! ;D ;D

But onto your questions: I was unfamiliar with this pickup, so I looked it up. KA claims it to be the "hottest HB on the market" at 27.5KΩ. You may have a bit of a mismatch issue no matter what you pair this with.

Normally, putting a bridge pickup in the neck position can cause mismatch issues, since bridge pups are normally a bit "hotter" than neck ones. But since you're pairing it with this bad boy in the bridge I wouldn't worry about it. If you have a mismatch issue, it's more likely that the bridge Motherbucker is swamping out the GFS rather than the other way around.

If you don't normally use combos of the neck and bridge, but just one or the other at a time, mismatch doesn't matter anyway. And if your SG is the type with separate V and T controls for each pup, you can adjust for bridge pup overkill if need be.

As far as how to wire this up, I gather that you want:

1) To split the Motherbucker into a single HB.

2) Series/parallel switching, perhaps, but whether you mean series/parallel between the 2 halves of the Motherbucker, or between your neck and bridge pups, or both, is unclear from your post.

3) No new holes in your SG.

I assume you don't want, since you didn't mention it, any single coils split off the MB, to split your neck pup, or any out-of-phase options.

I also assume that the Motherbucker has 8 wires coming out of the 4 coils.

I further assume that your SG has the std Gibby toggle switch, with either a Vol and Tone, or 2 of each.

Observations:

1) 2 push/pulls would allow for Series/parallel switching between the coils of the Motherbucker (one P/P) and splitting off one HB from the Motherbucker. If you have the 4 pot SG, a third P/P could give you series/parallel between the neck and bridge if you want that.

2) You could replace the toggle switch with a rotary switch to do these options also. This would keep a "stock" Gibson look since, over the years, Gibson has put the Varitone rotary switch on these guitars. I put "stock" in quotes since it won't be in the same location as the Varitone would be.

3) Any 3 HB diagram could serve as a starting point.

If you mostly use this on stage, and you like to (or need to) switch between settings in the middle of a song, the push/pull option is quicker than hunting for the right spot on a rotary switch. For real switching speed, there are "push/push" pots available (works just like the footswitch on any effects box), although these are tougher to find than regular push/pull pots.

I'm sure diagrams will be forthcoming, I haven't had the chance to hunt for one yet this morning.

[newey]

A quick look found this:

HHH LP diagram from ChrisK. This could serve as a starting point, It has a phase switch for the middle HB which could easily be eliminated. It also retains the std Gibby toggle.

[necksnapper]

Hi newey, You've got the jist of it. I'll try to clarify so you don't have to assume. We both know what that does.

As far as wiring,
1. Split the MB to single HB.(push/pull)
2. series/parallel switching, perhaps. I'm thinking MB (push/pull) but I'm open to the neck/bridge option.
3. Holes. Not in this one.

It's a standard 4 pot Gibson. I did consider a single coil split in the mix. I also considered a P90 in the neck which I haven't yet ruled out.
The MB does have 4 wires for each HB, and 4 wires for the GFS.
The toggle is standard and I'd like to keep it. Also 2 vol,2 tone.

I don't want a ton of options and I'm not a stage player. I'm more of a lock the door after work and try to improve for an hour or 2 kind of guy. And I'm sure you're familiar with the personal satisfaction of a successful rewire or build from scratch or near scratch.
One more thing. I appreciate the time you guys spend helping solve puzzles for each other. And I also enjoy the good natured smart assery.

[newey]

NS-

OK, I'm a "lock the door after work" guy myself so I can relate. I'm also a "turn the volume down, the wife's in bed" guy . . .

The diagram I posted will do what you want with a bit of modification. There may be another out there that is exactly what you want but I haven't found it yet. ChrisK's diagram uses 4 push/pull pots, but you would need only two. It also features 3 volumes to control the 3 pickups, with a single tone control. Not sure if you'd want that or not, in your scheme each half of the Motherbucker would get its own volume control, which could be useful for matching up the output levels between the neck and bridge.

It does keep the std toggle switch, and most other schemes for this sort of thing would have a switch replacement involved. Or adding switches.

Someone will be along soon, I'm sure, with other suggestions.

[ChrisK]

I would recommend that you first measure the resistance of each coil. You can assume that within each 5 conductor cable, both coils of the same humbucker will be found. Tag one of these cables for future identification purposes. Once you have measured the resistance, please post the results.

Once I see these, I can give some further advice about how you might want to wire this, For instance, if both pickups in the MB have the same resistance, one could presume that they are nearly identical. If so, one might question the need to have both available independently.

I have a DiMarzio Multi-Bucker (somewhere) that I modified for 8 wire like the MB. It made sense to do so since all four coils were quite dissimilar.

I'd ask WD but my experience with their acuity on technical issues finds them to be perennially stuck between a burro and a burrow (ie, what's the switching on the Kent Armstrong "special" 4P3T toggle switch - huh, we don't know?). (They are the only U.S. source for this.)

[necksnapper]

OK, just checked the resistance and here's the results.

HB #1, coil 1, red/black = 6.66k ; coil 2, green/white = 6.67k ; together 13.33k
HB #2 red/black = 6.64 ; green/white = 6.82 ; together 13.45
All together in series = 26.7k on my digital meter
wires are tagged and ready.

It's been a year or more since I installed the GFS currently residing in the bridge but I'm pretty sure it measured 16.2k(give or take a couple points)

ChrisK, I haven't figured out how to work the quote box yet, but responding to your statement about wiring both HBs independently, thats not what I'm after. I just want 1 of them independent. And maybe 1 or both in parallel. And I'll probably defer to your wisdom if you think it best advised to go a particular direction with this.
thanks, NS

[newey]

NS-

To quote text, copy n' paste the text to be quoted into your reply window, highlight it with your mouse, and click on the Quote tag button in the "add tags" menu that appears above the reply window. It's on the bottom row, 2nd from the right, and looks like a page with an arrow sticking out of it. This wraps your highlighted selection with the quote tags.

Your measurements suggest that the 2 coil pairs are in fact identical, your numbers seem well within the margin of error. Thus, whether you wanted to do so or not, there would be no point in having both halves independently selectable. You can pick either one for the split off.

Having the ability to put the neck HB in series with either the full MB, or one-half of it, should give you a beefy, dark sound. You may want to consider this as well as series/parallel between the 2 halves of the MB.

The switching to do this is a matter of personal preference.

[necksnapper]

Roger that .

put the neck HB in series with either the full MB, or one-half of it, should give you a beefy, dark sound

You have my full attention.

[ChrisK]

Be prepared to switch the wiring from one humbucker to the other within the MB as your listening dictates.

That being said, using push pull pots (you'll likely need the LP style long bushing ones for rear routed bodies) you can select between two things. since you have three things in the MB to select between (series/single/parallel) you will need two of them.

You might also consider a third to override the LP-style toggle switch for whatever is selected by the other two for the MB, to be in series with the neck pickup (der GeTurbo switch). I'm sure that a further demented use could be found for a fourth.


Now, before you get too uncomfortably numb, there is another possibility to consider. Each pickup in the MB is a narrow humbucker. These never sound quite like a normal side-by-side humbucker as the magnetic sensing aperture is smaller.

You could select which two coils that you use among the four.

My DiMarzio Multi-Bucker had its poles oriented NSSN or SNNS. I was told that something like NSNS messed up the sound of both pickups, but this pickup had two specific, different pickups within; a Chopper and a Fast Track 1.

Anyway, using a small magnet, you could determine the pole orientation and select the coils for the two of interest. For instance, I was using NSSN and NSSN as to additional combinations since each coil was so dissimilar. Picking two coils that have the widest separation combined with humbucking capability would give a wider/normal aperture humbucker that might be more tonally attractive.


In summary, one might want to pick the two switches to select;

both SC narrow hums in internal series, in series with each other
one SC narrow hum in internal series,
one SC wide hum in internal series,
both SC narrow hums in internal series, in parallel with each other,

a third switch to select whatever is selected above in override series with the neck.

I said "one might want to pick" since we won't know if any set of things are possible until they're A. chosen, and B. analyzed.

I won't analyze all possibilities up front.

We also need to know the magnet polarity progression. Use one pole (the same pole for all tests) of a pickup to test for the attraction to each rail of the MB. Post the progression such as attracts/repels/attracts/repels or attracts/repels/repels/attracts. we don't care about the actual magnet polarity.

[necksnapper]

ok, the magnets are arranged attract/repel/attract/repel, starting with the HB I labelled #1.

Picking two coils that have the widest separation combined with humbucking capability would give a wider/normal aperture humbucker that might be more tonally attractive.

So coils 1 and 4 may sound pretty good, or more appealing together. I like it.

In summary, one might want to pick the two switches to select;

both SC narrow hums in internal series, in series with each other
one SC narrow hum in internal series,
one SC wide hum in internal series,
both SC narrow hums in internal series, in parallel with each other,

two push/pulls may be able to produce the 4 scenarios above. PLUS a turbo switch. I'm already getting dizzy but Im game.
Of course, I'd be thrilled just to get the 1st and 3rd or 4th option listed, plus the turbo switcher.(wouldn't that bring us to 2 PP pots?)

I have several 500k PP alpha pots but they appear to be short shaft. I'll be ordering some long shafts today.

[ChrisK]

That's good to know about the magnet orientation. We'll call the coils, in order coming from the bridge, Aa, Br, Ca, Dr.

We ignore single coils in parallel for this design.

We will connect the coils as follows;

Aa in series with Dr (the wide bucker), we will call this Wh,
Br, in series with Ca (the narrow bucker), we will call this Nh.

We will use Binary Tree Switching, of the DPDT variety (the right column).

This will give us the following with two PP pots;

Pot 1 - Wh - down
Pot 2 - Nh - down
Wh in series with Nh

Pot 1 - Wh - up
Pot 2 - Nh - down
Wh

Pot 1 - Wh - down
Pot 2 - Nh - up
Nh

Pot 1 - Wh - up
Pot 2 - Nh - up
Wh in parallel with Nh


Add in a third PP pot for an override of the three-way for bridge combination in series with the neck as in "Take 1" section "E" in Fun With Toggles & Push-Pull Switches,

And a possible fourth PP pot for phase reversal on the neck pickup (simple is).


Then there won't be a welding job that you can't do.

[necksnapper]

I have ordered more PP pots and my desk is covered with printouts. I'm thinking I should be soldering by Friday. I just have a few questions (maybe quite a few).

On the MB, I'll only be using 4 wires, since I'll be wiring the outer coils and inner coils in series,right?

We will use Binary Tree Switching, of the DPDT variety (the right column).

The top picture is all I'm concerned with?

I'm pretty excited about this. I tend to get confused looking at schematics so I'll try to draw more of a diagram showing the whole layout and submit it for corrections in the next day or 2. Of course, If anyone has it already drawn it won't hurt my feelings if you post it first.

And a possible fourth PP pot for phase reversal on the neck pickup (simple is).

I think not on this one, but I have a Firebirdesque project very near the wiring stage that I may go for it on. You'll likely hear about it in a near future thread.

I'll be back

[ChrisK]

On the MB, I'll only be using 4 wires, since I'll be wiring the outer coils and inner coils in series,right?

Yes, but it's up to you to get the right sets of wires for the coils.

The top picture is all I'm concerned with?

The top right drawing. "A" is one pickup (Wh or Nh) associated with the switch left next to it and "B" is the other pickup (Nh or Wh) associated with the switch right next to it.

The red switch arrows are for the series position and the blue switch arrows are for the parallel position. If both switches are in series, both pickups are in series, if either switch is in parallel, that pickup is on regardless of the other. If both are on, then they are in parallel.

[necksnapper]

I hope everyone had a lovely Thanksgiving.
I'm trying to come to grips with these schematics and I need to know if I'm in the ballpark.
I drew the binary tree switch out and I think it looks OK. Now I'm looking at

a third PP pot for an override of the three-way for bridge combination in series with the neck as in "Take 1" section "E" in Fun With Toggles & Push-Pull Switches,

and I'm thinking the A box is the neck pup and the B box is the bridge pup (or in my case, the entire Binary Tree diagram?) The squigly lines next to the A, B boxes are their respective volume pots? And it doesn't matter which pot the DPDT switch is on( I'm thinking neck volume).
Once I get it drawn, I'll try and figure out how to scan it and copy it to here for inspection.

[newey]

and I'm thinking the A box is the neck pup and the B box is the bridge pup (or in my case, the entire Binary Tree diagram?)

Yes

The squigly lines next to the A, B boxes are their respective volume pots?

Yes. The dot at one end of the squiggle represents the CW terminal of the pot.

And it doesn't matter which pot the DPDT switch is on( I'm thinking neck volume)

Correct. Fitment and wiring convenience may suggest the use of one or t'other, and consider ease of use during playing where a choice presents itself.

Looks like you're not only in the ballpark, you're on deck and the organ is playing . . .

[ChrisK]

A box is the neck pup and the B box is the bridge pup (or in my case, the entire Binary Tree diagram?) The squiggly lines next to the A, B boxes are their respective volume pots? And it doesn't matter which pot the DPDT switch is on( I'm thinking neck volume).
Once I get it drawn, I'll try and figure out how to scan it and copy it to here for inspection.

The "A" box is one pickup (or structure). The "B" box is the other pickup (or structure).

In the "Take 1" section "E" in "Fun With Toggles & Push-Pull Switches", when in series mode, "A"'s volume pot functions as an adjustable series shunt across "A". In essence it gradually shunts out or reduces to zero "A's" contribution in the series mode.

"B"'s volume pot functions as an adjustable master volume for the entire series chain.

So, "A" is shunt-able, "B" is not. You can control the contribution of "A", but not "B".

Choose as you wish (what "A" and "B" stand for). I would likely put the series/parallel switch on the pot that I wanted to be the master volume in series mode.


In parallel mode, both volumes function as normal. Note that the pickups are connect to the wipers on their volume pots and the CW lug goes to the LP toggle switch

[necksnapper]

OK, I didn't post my diagram. Instead I pulled out my cordless screwdriver and soldering iron. 8 hours later I turned on my Champ and braced myself. I am sooo glad that SG's have access to the pots from the rear.
Judging from buzzing and popping, I'm guessing that somethings not grounded right. The pups do play but its not pretty. It'll probably be a day or 2 before I get a chance to inspect thoroughly.
Thanks for all the help so far, I may need much more.

[ChrisK]

There was more than one reason why I had you measure the resistance of the pickups.

You could attached you multi-meter to the output jack on the guitar and measure the resistance for the different switch positions.

Make sure that all volume and tone pots are at "10" or maximum on.

First start with guitar parallel and only the bridge MB selected. Try the different positions of the push pull pots that select the various momma-bucker coil sets. Either two-coil set in binary parallel will be about 13K Ohms. The two of these in binary series will be about 26K. The two of these in binary parallel will be about 6K5.

Record your results, for the state of the switches (up vs down) and resistance. There will be four measurements.


You should hear slight tonal differences between either two-coil set (Wh vs Nh). This is how you can later confirm that you have either one selectable (since the coils area all so similar in resistance, measurement can't help).

Now select only the neck, also in guitar parallel mode, You should read about 16K Ohms.

Record the result.


Now set the bridge pickups for both on in binary parallel. This should be 6K5 Ohms.

While still in guitar parallel mode, select both the neck and middle. You should read about 4K6 Ohms.

Now select guitar series mode, You should read about 22K5 Ohms.


HTH

[necksnapper]

I'm getting close. I don't have any more buzzing/popping but something is not quite right. The readings on my meter are close, but plugged in something is amiss.
I dig the turbo. ;D
I will get this dialed in, Its just taking a while. Every couple days I take another look, and every time I find something else I missed before.

I appreciate the help and I'll keep checking in.

[ChrisK]

Could you post some digital pics of your wiring?