More Fun with the Modelo Uno: Forward and Lateral Motion

Discussion in 'Luthier's Corner' started by Freekmagnet, Jul 9, 2019.

  1. Freekmagnet

    Freekmagnet Commercial User

    Since “completing” Build #3 earlier this year, I’ve had a little time to contemplate moving forward with a few new projects. I’ve made some small improvements to my work area, upgraded my pickup winding operation, and come up with an idea for an all-new pickup design. On top of all that I’ve had an itch to build another bass. I’ve decided that rather than designing another instrument from scratch, I’m going to make a few improvements on my existing design.

    Because my next build will be basically the same bass as the previous one, I wasn’t sure if this project warranted a new thread. In a sense, this is could be seen another stage in an evolution, so I felt a new thread would be in order. Hopefully, this thread won’t be as epic as the last one.

    Here’s the changes I’m looking to make:

    1) I want to make a laminated maple neck as opposed to a 1-piece flat-sawn neck.

    2) I’m going to make some slight changes in the body - specifically, I want to do away with the plastic battery box and make a dedicated cavity and a wooden cover that matches the finish. If I feel inspired, I might hollow out a little of the section between the pickup and the neck area.

    3) A sculpted neck heel. This is a slight improvement that is easy to implement - the challenge will be to make it look good. Most of the sculpted heels I’ve seen are just blobular shapes that don’t really have a shape. It would be completely fair to call me anal, but those rounded heels offend my design sensibilities.

    4) I might experiment with a different kind of neck plate. I’ll post some drawings later - this idea may be a bust and might not even be an improvement.

    5) The new pickup. From this time forth code-named “Exotica”. There is a chance that this may negate the battery box on article #2, but I’m not making any promises.

    I’ll be posting a few photos later today.
    Last edited: Jul 9, 2019
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  2. Bruce Johnson

    Bruce Johnson Gold Supporting Member Commercial User

    Feb 4, 2011
    Fillmore, CA
    Professional Luthier
    Jeremy has shared the design secrets of the Top Secret "Exotica" pickup with me, and it's really interesting. An internal configuration that I don't believe has ever been done before. It has some real potential advantages.

    As I keep saying, there's still a lot of unexplored territory in electric guitar/bass magnetic pickup design.
  3. Freekmagnet

    Freekmagnet Commercial User

    Thanks, Bruce!

    I agree - there’s a lot of room for experimentation in pickup design. Because it’s not all that straightforward, I won’t go as far as saying that pickup making is an overlooked part of designing instruments. There’s enough tried and true pickup solutions out there that are also relatively inexpensive. But if you’re willing to invest a little time and energy, making pickups is a really rewarding experience.

    And just to be clear, I’m only being secretive about this pickup because I’m not 100% sure that it’s going to be feasible to build. (I wanted to clear that up because a lot pickup guys are really protective about their ideas for whatever reason.) My initial experiments have been promising, but I have yet to actually build a functioning prototype. Bruce machined a part for me that will help make the prototyping process manageable - I’ll be posting a picture of it later today.
    Last edited: Jul 9, 2019
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  4. mapleglo

    mapleglo Gold Supporting Member

    Sep 7, 2013
    phoenix, az
    I'm looking forward to your updates. Sub'd.
    Freekmagnet likes this.
  5. Freekmagnet

    Freekmagnet Commercial User

    I made some improvements on my pickup winding apparatus. I generally use really thin cardboard for my bobbins. Why? Because it’s cheap, you don’t need special tools to cut it and I can make the walls thin enough that I can fit enough wire into a small space. The downside is that the bobbins are really fragile and tend to flare out once I lay some wire in them. This unpleasantry is remedied with a set of “holders” I made out of some 1/4” maple I had laying around.

    Here’s the cardboard bobbins inside of the holders:


    The disk on the right is an MDF assembly that attaches to the winder platen. This allows me to screw the holders down to the surface.

    Here it is attached to the platen:


    This allows me to easily center the bobbin assembly on the winder. (The photo looks wango, but that because of the lens.) Bruce drilled and threaded a couple of holes on the platen for me. He’s got the tools to put them dead center on that circular part. Anyway this is cool because now I can put all kinds of crazy attachments on my machine. It’s amazing what a pair of holes will do!

    Here’s a batch of coils I wound last night:


    They all look really good!

    I’ll have more updates on this project later.
    Last edited: Jul 9, 2019
  6. Freekmagnet

    Freekmagnet Commercial User

    OK, on to the next part of this puzzle. First, allow me to put on my opinion hat. I use the word “opinion” because I have found that in the pickup-making universe, the ultimate truth is a relative thing. There’s some laws of physics that definitely apply, but at the end of the day there’s a lot of conjecture involved. Ultimately, one winder’s findings may be different from another’s. I’m just stating what I have discovered through my own admittedly un-scientific processes.

    Let’s first go over magnetic materials. Most pickups these are made of various grades of Alnico or ceramic and every once in a while you’ll see neodymium. (There’s some weird pickups out there with rubberized magnets, but I just give a brief overview here)

    Alnico has been around since the old days, and a lot of “traditional” pickups are made with Alnico - Fender, Gibson etc. Alnico is great because you can design a pickup that has a well-rounded tone - the highs are manageable and the mids are sweet. They’re also pretty versatile and forgiving - you can make a pretty good-sounding pickup by just wrapping some wire around it.

    Ceramic magnets are stronger, so you can build a really bright pickup with them. However, they can also make a really stiff and harsh-sounding pickup. Ceramic pickups have a really fast bass response. A lot of more “modern” bass pickups are made with ceramic, but ceramic pickups don't necessarily have to sound "modern". A perennial fave here on TB is the classic T-40 pickup.

    Neodymium is relatively new on the scene. I’ve been seeing a few more neo-driven pickups out there lately, but it’s still considered to be kind of “exotic”. Their main characteristic is their intense strength.

    I’m writing this in an effort to dispel any myths about neodymium pickups. I’ve been playing with them for a while and they don’t magically make your pickup more amazing and they don’t give your pickup out-of-control output or anything. If anything, most of the pickups I’ve made with neodymium sounded really similar to Alnico-driven pickups. Because of their strength, you will have to alter your design significantly.

    I’ve gotten strange requests from people to build things for them like a neodymium p-bass pickup, and my answer is usually, “why?” A p-bass pickup is basically p-bass pickup regardless of what magnet you put in it. Besides you can buy a neo P on eBay for $50. I’ve actually read statements from guys who claim that neos sound so different that the human ear is not ready for the way it sounds!

    Anyway I’m calling BS. You can make a good-sounding neodymium pickup, but it won’t be the magnet making the miracle. It’s just a magnet like Alnico or ceramic.

    What’s great about neodymium magnets? Well, it’s their intense strength. If you want to make a smaller pickup, then you can use a small neodymium magnet to drive it. Neodymium magnets are available in all shapes and sizes, they’re relatively cheap and it’s easy to experiment with all kinds of cool magnetic structures.


    Next, let’s talk about sidewinders. I’ve been building sidewinders for a couple of years now. I used my sidewinder pickup in my Sirena Modelo Uno. They've been around for a while - most infamously in the Gibson EB-3, but they're pretty uncommon pickups. I believe that this largely because they are more difficult to manufacture, but I'm not sure. While the Gibson pickup isn't the best sounding pickup (they're affectionately known as the "mudbucker"), sidewinders are generally very bright-sounding pickups and have a neutral-sounding midrange. While they are humbuckers, some say that they have an almost single-coil sound. I've heard them described as being "natural" sounding, and I think that is a fair assessment. My theory is that this is largely due to the very narrow sensing area; basically, the central pole does 90% of the work.

    I installed my sidewinder in the bridge position, and while it sounds very clear, the narrow sensing area presented a real challenge. The pickup just didn't put out a ton of low end. I ended up having to use a preamp to fill in some of the bottom, enhance some of the mids and cut some of the highs. The bass sounds great and I've been gigging with it, but I wanted to maybe have a pickup that didn't rely so heavily on a preamp.

    Bruce and I had been talking about it, and he suggested making a wider pickup with a wider aperture. However, I'd already been down that road, and widening the space between the center and side poles didn't do all that much - again, the central pole does most of the work.


    Next on the list are multi-coils. I haven't a built one myself, so I can't say much about them, but supposedly they are thick and bright sounding at the same time. Theoretically, this would be due to the skinny coils wired in series. The Wal bass and of course, the X-Strange AMB-2 are both loaded with multi-coils.


    Which brings me to new pickup, code-named "Exotica"

    I've decided I'm going to attempt to build a neodymium-driven multi-coil linear sidewinder. It doesn't get much more exotic than that

    The idea is that I want a small pickup with a wide sensing area. Each string will have it's own sidewinder with it's pole running parallel to the string. This will give me the widest sensing area in the smallest space. The smaller neodymium magnets will allow me to make 8 tiny coils.

    Here's a picture of my first attempt, which was an utter failure:


    Why did they fail? Well the magnets are really strong and the bobbins and the wire are really fragile. Each set of coils would pull into one another and would either snap the wire or break the bobbin. On my second attempt, I tried putting the magnets underneath the bobbins, but I really had the same problem. I did manage to get 2 strings working and it sounded amazing. Really full sound.


    I used some polypropylene I had for the bobbins, but the plastic glue didn't hold. They were falling apart as I was putting them together. And again, the magnets would pull into one another and break the wires.

    So, Bruce made this part for me:


    This is basically a prototyping jig that will hold everything together while I assemble the coil/pole/magnet pieces. Because of space restrictions, the pickup will pretty much design itself. I can only add so much 44AWG wire. The biggest problem to solve will be the wiring. There's a lot of points of failure. I'm thinking that I might have to design some kind of circuit board to hold the coils in place.

    I'm hoping to get started winding this week.
    Last edited: Jul 10, 2019
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  7. ctmullins

    ctmullins fueled by beer and coconut Gold Supporting Member

    Apr 18, 2008
    MS Gulf Coast
    I'm highly opinionated and extremely self-assured
    Wow!!! :hyper:
  8. tbrannon


    Jun 11, 2006
    So cool.
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  9. Freekmagnet

    Freekmagnet Commercial User

    Alright, here’s the last post for the day. First off, posterity’s sake, here’s a recent drawing of the bass:


    It’s the same as my last build. I just added a rough drawing of the new pickup as a placeholder. I don’t actually know what the pickup is going to look like yet.

    I think I’m going to finish it in pearl blue with white binding. I’ll use holly as binding - the ABS binding was really easy to install, but I didn’t like difference in materials during the finishing process. The epoxy won’t soak into ABS like it does the wood. It just sits on top and it didn’t sand very well. Anyway, we’ll see how the holly binding goes. There’s a guy who sells it on eBay.

    Here’s my wood pile:


    I found the two shorter pieces of poplar in my stash. They are leftovers from a previous build. Those will be for the back. I’ll make the cap from the longer piece in the back. It’s too bad I wasn’t in the mood for a clear-coat finish - they actually had some nice, clear poplar at Mayan today. It was that nice, cream-colored Wood with no green streaks.

    The 5/4 hard maple on the right is for the neck. I was looking for walnut, but most of the pieces they had at Mayan had a lot of little knots. Maybe next time. I want to build a laminated neck, so we’ll see how that goes.

    I haven’t ordered the fretboard yet, but I saw that LMII has some roasted maple pieces. If it’s dark enough, I might get one of those. Or maybe I’ll go for plain old maple. I’m kinda digging the “all-domestic woods” vibe. Either way, I’ll have to figure that out soon - they’re having a sale on truss rods at LMII right now.

    The MDF in back is for new templates - just in case.

    Hopefully, I’ll get started on this stage within the next week.
  10. ardgedee


    May 13, 2018
    What would happen if the pickup were longer and mounted at a diagonal?

    Thanks for this thread! I’m enjoying the posts and your thoughts on pickup design. It seems like a technology that could go in all kinds of directions but so far mostly hasn’t.
    Freekmagnet likes this.
  11. 40Hz

    40Hz Supporting Member

    May 24, 2006
    The design goal Gibson had with their sidewinder was to produce a sound similar to a P90 pickup but without the noise. So their target was to build a “humbucking P90 sound” so to speak.

    Regarding a pickup’s sensing area (or aperture) and sidewinders:

    Bill Lawrence’s sidewinder design for the Ripper is an extremely narrow aperture sidewinder pickup which, along with a carefully selected (for its strength) Indox ceramic magnet, gave the Ripper its signature sound and response. Most times it’s referred to as being “clear” and “focused.” And it’s fairly touch sensitive as well. Which is a very different set of characteristics compared to the sidewinders you’ll find on an EB series bass.

    Interestingly, the Gibson G-3 was Bill’s experiment in the other direction. On that bass you have three widely separated narrow focused Alnico single coils. But the unusual switching scheme (dubbed the “buck and a half” configuration) was designed so that they’re never soloed. The switch choices are: 1&2, 2&3, or 1&2&3. So with that you effectively get an extremely wide aperture humbucking pickup at all times. And like the Ripper, the G-3 has a sound entirely its own.

    Supposedly each of the three pickups in the G-3 was wound to have slightly different electrical characteristics. Something which wouldn’t surprise me considering it’s a Bill Lawrence design. But I can’t say for sure if that’s true. However, each of the three pickups in a G3 has a different part number and wiring color scheme. So that makes me suspect there’s a good chance there might be some truth to it.

    But back to your pickup design! Very cool idea. Just goes to show there’s still room for innovation and out of the box thinking when it comes to mag pickups. Hopefully it’ll work out the way you’re expecting. Things have been a little dull in mag pup land. It’d be nice to see something new come on the scene.

    Luck! :thumbsup: And please keep us posted. :)
    Last edited: Jul 10, 2019
  12. Freekmagnet

    Freekmagnet Commercial User

    I dunno - that’d be another experiment!

    That’s exactly why I started making pickups. When I first got started building basses, I quickly realized that my pickup choices were all pretty much the same; Fender derivatives or EMG soap bar style pickups.

    Pickups don’t have to be boring. Like, you’re harnessing the powers of electromagnetism to interpret string vibrations - what could be more exciting than that!
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  13. Freekmagnet

    Freekmagnet Commercial User

    That sounds about right. My first sidewinders definitely sound “clear” and “focused”. They actually sound really good, and I built an onboard preamp specifically for the pickup. I’ve been gigging with it in a 7-piece R&B band. It holds the rhythm section down no prob.

    The new pickup will have different vibe. Fatter for sure, maybe not as intense in the attack.
  14. 40Hz

    40Hz Supporting Member

    May 24, 2006
    Now that hits me right where I live. I’m one of those players who thinks “punch” and “cutting through” are vastly overrated qualities. I like a bass that has a softer attack and a bigger warmer fuller sound most times. Any kitty can be made to snarl and growl. But I like it more when you make them purr.

    Tell me more about that sidewinder specific preamp you built if you have the time. I’m a bit of a connoisseur when it comes to preamps. And since I’m a big fan of sidewinder pups, you’ve definitely piqed my interest with that one. :)
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  15. Freekmagnet

    Freekmagnet Commercial User

    That particular tale is more adequately told here:

    Build #3: La Charra: the Semi-Hollow Adventure Continues

    I don’t want to muddy this thread too much with stuff about my previous build, but in brief, the preamp I built for that sidewinder is basically a StingRay 3-Band pre with an LT1352 opamp. I swapped out a few caps to center the bass boost around 35Hz.

    It’s definitely got a real hi-fi vibe, but I’ve been getting a pretty good meat & potatoes tone out of it playing live. My buddy came over the other day and was totally rocking that “We Got to Get Out of this Place” tone with it.
  16. rudy4444


    Mar 13, 2012
    Central Illinois
    Interesting... I used to see a ton of wacky ideas over on the pickup winder's forum...
    Matt Liebenau likes this.
  17. Freekmagnet

    Freekmagnet Commercial User

    Here’s the magnetic assembly:


    This was not easy to assemble! It took me a couple of hours to figure out a way to do it. I had to assemble each pole structure individually, glue them together with CA glue, and then glue each pole into the slot. I had to press fit the poles in there with a vise because the magnets would force each other out of the slot. If I end up doing a production piece, I’ll have to come up with a jig to hold the poles together while I pop them into the base.

    Now that the poles are all affixed in their proper places, I can safely place the coils in there without having to worry about the magnets crashing into each other and breaking the coils. Next, I have to figure out how to wind these tiny coils in such a way that I can wire them up.
    Last edited: Jul 16, 2019
  18. Freekmagnet

    Freekmagnet Commercial User

    I got some milling done over the weekend, and I joined the body blanks together. Here’s a picture of the top half:


    I did the bottom half the day before. I just milled the edges and joined the with West Systems.

    I also milled the neck blank and cut it down into strips. I’m going to let them sit for a few days before I glue them up to make sure they don’t do any twisting.

    Here’s a picture of them alongside my fretboard that came in the mail from LMII this afternoon:


    That blue thing is a color sample I sprayed a few months ago.

    I ordered a padauk fretboard. Originally, I wanted to get a roasted maple fretboard and keep my woods all North American. However, I have not really seen any roasted maple examples that really knocked my socks off color-wise. Admittedly, I have not seen many examples - mainly just the Ernie Ball instruments at GC and I wasn’t all that impressed. I’m the end, the roasted maple fretboards were pretty expensive for a wood color I’m not really all that sure about. I decided on padauk - it’s a great color, it was $12 cheaper and as far as I can tell, it’s not critically endangered or anything. I think it’ll kick a** next to that pearlescent blue. In the future I’ll keep looking for a roasted maple sample I like.
  19. Scoops

    Scoops Why do we use base 10 when we only have 8 fingers Supporting Member

    Oct 22, 2013
    Sugar Creek, Wisc
    Just in case you weren't aware, that padauk FB will turn brown as it ages. It looks like the one you have has started already.

    As far as roasted maple fingerboards, try here
    Roasted (Thermally Modified) - American Specialty Hardwoods

    If you cant find the size you want, they will custom cut to size. I don't think they slot and/or radius though
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  20. Freekmagnet

    Freekmagnet Commercial User

    Haha thank for the heads up - I’m actually counting on it turning brown! Or reddish brown.
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