Sunday, March 13, 2011

Universal Pickup

There are many things about electric guitars that are never questioned - things that stung just because they worked for pioneering models and nobody saw why one should do it another way, then it became habit, tradition, cult, whatever - but that I can never take for granted. Amongst these is the necessity to have these two pickups in neck and bridge position (plus in centre when there is a third one) with specific use and sound... Even extremely experimental guitars such as the Teufel Birdfish stick to this! I've always had in the back in my mind: 'what about a big pickup that would go from the neck to the bridge and contain multiple combinations?' - today I decided to check how it would look... 

I'm not an engineer so there is maybe a major flaw to this idea that will jump to the eye of anybody more learned about sound and electronics, but I wish I could meet someone who could put some thinking in it. Imagine 36 magnet plots plus a few blades, that could be combined in many ways (with rotary switches, I love rotary switches!) It feels more exciting that all the emulating gizmos stuffed in the last Gibson luxury models, and might create completely new tones (and not fake ones that are already commons)...

Feedback is welcome!



  1. I don't know if you've ever played with pickup phasing, but I found the tonal effects of phasing to be detrimental to the sound of regular pickup combinations. I suspect this is mostly because of comb filtering; where certain frequencies of the entire spectrum are boosted, while others are cut in an in-harmonic manner.
    By contrast, the position of a single pickup will boost frequencies in a bell curve manner, without comb filtering.

    In my opinion, the best tonal differences come from a combination of string gauge and amplification technique.
    There are other experiments, such as Third Bridge Resonance that can add significant colour to tone.

    Check out Yuri Landman's website for more on third bridge.

    Also, I'm continuing my experiments with stereo pickup fields.


  2. Don't forget the Gittler guitar which had 6 pickups - one for each string - running lengthwise beneath the strings.

    There's a bass - I forget the brand now - that has 12 pickups in one enormous casing and the facility to select endless permutations.

  3. Or - what about something like this -

    How about individual sliding pickups for each string?

    Mind, I honestly prefer a guitar NOT to have these infinite choices. I'd prefer a guitar to have one sound that it does really well. It's like these Variax guitars - there's just too much going on with them and you end up using none of it.

  4. Thank you for your comment Michael,
    actually, this idea of a unique pickup doesn't come from a quest for tone, but is pure creative speculation - though one might be surprised by the result... about my tone, I've solved the issue with the best solutions IMHO:

    1. I don't really care about tone, I don't believe in the guitar business doxa that you have a tone in your head and you have to buy a lot of gear to reach it, I think that the gear comes first and you adapt to what you have...

    2. I'm a pedal person, I started with punk/post-punk with zero guitar hero fetish, the point was to be noisy, loud and cheap so since my first Boss turbo overdrive to my currently-shipping-from-canada bitcrusher, when I think sound, I think effect.

    3. and the most important, my current philosophy is a new tone = a new guitar - that justifies to get/build new guitars regularly...

    about the technical details I'm still learning, like I wrote I'm no engineer and I still have a long way before I understand the electronic subtleties behind tone, I can only be empiric. I hope than some day I'll be able to experiment as you do!

  5. Ability to lift/pull PU's (for balancing output) is necessary for me so that's why separate PU is preferable. Also assembly even with 5 strat PU is pretty heavy :)

  6. separate volume controls for the different parts of the Universal Pickup should be possible! (cool strat BTW).

    didn't think weight would be a pickup issue, but I have no problem with plain mahogany bodies, so...

  7. I'm like you, I don't know about the realistic-ness of this pickup, but I do like the look.

    Sliding pickups are another possibility for getting a larger range of tones.

  8. I think I can help you with the design a bit, but I have a short-ton of questions for you. This is a very deep subject we are entering.

    There *are* very definite reasons for the accepted conventional pickup positions. A neck and bridge pickup give very different sounds that work quite well for rhythm and lead work. Having said that, there is nothing that says we can't experiment and see if we can come up with something new.

    Building something of this level requires more than just a basic functional specification or wish-list; we have to talk about the way the pickup system is expected to work, and during this process we can explore what is possible/practical given the size limitations of the package. Once we have a complete system spec together, we can go to the actual design specification. With the design spec, we get into more details of what things will be made of, materials, etc. With that, a proof-of-concept prototype is made (hopefully) and we see if our idea makes any sense. Then there will be tweaking, changes, alterations made to make the piece something that is reproducible, etc., etc. When everyone is happy, we have a working pre-production prototype. (who builds it after all of this is a different ball game)

    This is probably a bit more work than you bargained for, but I figure it will be very rewarding in the end. I doubt we will be able to contain all the back-and-forth in this blog (it would be very boring to most), and I expect it will take a few years to get it all correct.

    All knowledge begins with a question. My initial questions are:

    1. Are you looking for mono or stereo/multichannel outputs?
    2. Is this pickup system going to be for a gigging guitar *or* just something meant for one particular guitar design that will be kept locked up in a studio and rarely if ever see the light of day?
    3. If the pickup system is something you would like to retrofit to other instruments, or pass on to the DIY community, would you consider it being paired with a more conventional pickup layout to allow the *option* of conventional sounds? I figure at some point, some folks will have to switch to playing conventional rhythm or leads. Few want to build an expensive one-trick pony.
    4. Is this to be an active or passive pickup system?
    5. (and please understand this is a very valid question being asked with the best of intentions) Is the look of the pickup design more important than the sonic or functional result?

    If you are an external-effects-box person, I would suggest that a wide-range or set of wide-range sounds would be best. You can always narrow out the range via EQ or other processing in your outboard effects. It is much more difficult to replace something that isn't there to begin with. Note that there are already wide-range options from the Lace folks with their Alumitone designs, but this doesn't mean we can't build our own current-transformer-based pickup.

    One thing that concerns me is your desire for individual volume controls for different parts of the pickup. Add to that the rotary-switch issue selecting 36 individual pickups in varying combinations and you will soon have a wiring harness that will make a 1960s Vox guitar organ look simple by comparison. More wiring, even with shielding, adds more paths for hum/noise and more potential failure points. Even with 36 to the 36th power of combinations/permutations, will there be more than 2% of useful sounds available? Will the guitar player end up looking like a frustrated safe-cracker on stage spinning rotary switches and pots to get the sound needed for the next song?? If you are using outboard/rack effects, don't you already have excellent options for selecting pre-programmed sounds?

    Again, I have many more things to discuss with you so please drop me an e-mail. This could be the start of something very interesting!

  9. thank you Ben, I will answer to all your points in the coming days - some things I have to figure out because they didn't even come to my mind... of course the new inputs are welcome... then probably we'll go on via e-mails (leave yours in a next comment - I won't publish it)

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  11. @Ben, some answers:

    about pickups positions: for a long time I also thought that at least for the neck pickup there was a precise nodal point - I remember asking a luthier about it who answered that it was a pro secret - where the harmonics sound the best, but then in Leo Lospenato's book - where a lot of guitar makers traditions are proven false - it's said that it's true only when you play open strings - that is not most of the time on a solid body... and many early Gibsons hollow bodies have just one pickup in center position... so the pickups sound different but they are also different, and there could be other positions too.

    1. I would go mono - it shouldn't be a super sophisticated pickup than just sound fanatics would use. on the other hand, my rickenbacker 620 has also a stereo output - that i never used - and it doesn't seem overly high-tech.

    2. should be like a regular pickup, for any situation - gigging and studio.

    3. fitting it to a 2 pickups guitar means to route a big cavity in it, so there's no coming back... but it should be able to fill up for classic pickups, plus extras.

    4. also for simplicity I favor passive pickups, but I understand that it could require to be active.

    5. like everything related to electric guitars, the look is important - I don't know anybody anymore who would overlook coolness in the name of tone.

    I'm a pedal person, so I mostly alter the sound of my guitars with effects, but I wouldn't be dependent on them for the sound, it has to be good anyway.

    I would go for switchable preselected sounds, endless combinations often turn unusable and blur the possibilities. I recently tried a 3-humbucker Airline, you quickly leave the 6 knobs alone as the 5-position switchblade provides already a lot of different sounds... 2 rotary switches could already propose a lot of sounds - I have that on my Musima Eterna...

  12. Pickup positions... Agree with Mr. Lospenato that precise nodal points are dependent on where the
    string is fretted, and every bit as importantly, where it is struck/plucked. Anyone can see this with
    their own eyes just by using a common piece of string and a strobe light. With any given guitar, we
    are working with somewhere around 6 inches of space between the bridge and the neck heel where we can
    place the pickup. (I remember Hofner actually sticking a pickup under the fingerboard on a guitar
    many years ago, but they were the exception to the general rule)

    As for the luthier who said it was a secret... that's pure deliberate mystification. I have run into
    too many of those types. Something I learned from both experience and an exceptional recording
    engineer is to experiment and use my ears. Eventually, you'll find the position that sounds best, and
    more than likely it will be different for each guitar design. I look at a guitar (and the
    accompanying amplifier) as a resonant system, and realize that resonance varies with the mass and the
    materials used. Having said that, over the years I've found that from a basic plug-it-in-and-crank-
    it-up perspective, a lead guitar sound is typically associated with a bridge pickup and a rhythm is
    associated with a neck pickup. There are many exceptions to this! Frank Zappa used a three pickup SG
    and a MuTron III to produce an exceptional lead guitar sound in the 1970s, and Jimi Hendrix could
    produce an exceptional lead sound with any pickup he chose. I don't believe there is one sole perfect
    guitar sound, but there is most likely a set of sounds that are more preferred. Craig Anderton
    mentioned in his DIY guitar effects book that the best sounds seemed to have a vocal quality to them.
    Maybe he never liked punk rock? In the final analysis, it really depends on what sonic qualities the
    given artist prefers. That really has to be defined.

    I mentioned that I viewed the electric guitar and the amplifier as a complete resonant system. I
    believe the amplifier to be every bit as important. In your case, we have to consider both an
    amplifier and a given set of external effects. This will more than likely necessitate some sort of
    compromise so the final pickup form will work reasonably well with both worlds.

    Mono output makes sense. This simplifies things greatly on the switching end, though if single-string
    pickups are desired things will become quickly complicated once again.

    Thinking through the possibilities over the last few weeks, I figure the much-reviled swimming-pool
    rout will be needed. This isn't really as bad as it sounds, at least as I envision it. The typical
    Strat swimming-pool rout (everyone does it differently) is rectangular with roughly 13/16ths depth,
    and a 1 5/16ths deep slot at the top and bottom to accommodate long humbucker-style adjustment screws.
    (this assumes a Strat body of 1 3/4" thick) A lot of folks really hate this rout, but if we are
    talking a complex pickup with multiple poles spread over a big area, there is little else we can do.

  13. Mass can be added back by encasing the whole pickup in an aluminum case that fits snugly in the rout,
    and is bolted in at multiple points. The added benefit of the case is good EMI shielding. (common-
    mode noise like hum is something different)

    Will some wish to retrofit this design to existing instruments? Possibly, if it ends up working out
    that well. For the purposes of your custom design, it shouldn't be a problem. If you really are
    worried about the loss of wood between the bridge and the neck pocket, you could always make the body
    thicker with contour cutouts front and back, and chose wood that is a little less dense to cut back
    the weight.

    I thought of having it sit in the space between a traditional neck and bridge pickup, but those could
    be eliminated in favor of the new design... hence the swimming-pool rout. There is also nothing that
    says we must be tied into one and only one pickup design variation forever for the instrument. If
    anything, making multiple rectangular cases is imperative to see what we like best. Dan Armstrong
    took it further with his Lucite guitars that allowed for pickups to be physically changed out without
    disassembling the entire instrument. The pickups were molded and slid into a well that had banana plugs at the bottom.

    Passive or active is a choice for later on in the design process. I personally prefer passive as
    well, but if we are dealing with multiple low-output poles... we might have to change that thought.

    Active isn't all that difficult as long as we keep the number of poles and wiring to something manageable. There are plenty of options available, and nothing says we have to put battery boxes on the guitar body. A
    guy named Tillman adapted phantom-powering to guitars some years back & his research is on the net.

    Aesthetics/visual appeal... As I'm seeing the rough idea in my head now, it isn't too far from your
    sketch here. I don't see the poles in the same places as your sketch, but that really has yet to be
    worked out.

    I'm really hoping for a wide-range sound that allows the user to narrow it down to whatever his amp or
    pedals/rack requires. In the end, it will make the system more versatile. The compromise is that it
    may take the end-user time to dial it in for the best sound.

    Switchable presets... This needs to be given serious thought. The end-result must not be overly-
    complex, but it must also allow a fair range of adjustment. How many rotary switches or blade
    switches do you propose and what do you want each one to do?

  14. I'm not a strat person so my opinion there is irrelevant but I've read several times that the 'swimming pool rout' upgrades the sound of the guitar... routing a fender-like planck guitar is not much a problem, when it comes to an archtop it's more difficult - not to mention hollow-bodies (it must work on hollow-bodies!)...

    but yes, the universal pickup is firstly an alu box lodged between the bridge and the neck (this might even influence the sound - unless it's all potted, i don't know how much is necessary...). it could also be one bloc with the pickguard and the electronics, like old Framus or Egmond units...

    phantom powered active pickups in new to me but it's great idea, I wonder why it's not standard yet, at least amongst metalheads using EMGs...

    for the sound selection, maybe there should be two systems - like on a Jaguar, but that works - one allowing fine selection with mix knobs, and one with narrowed down pre-selected sounds - let's say 9 or 12, like on a photo camera where you can switch between manual and automatic modes...

    of course the sounds can be selected only when the pickup exists, noone can tell before what will be interesting.

  15. I agree that the Tillman FET pre sounds great, and would be easily adapted to this project, but I'm unsure of the necessity of a preamp.
    I have found the Tillman pre to add very little gain to the source; by design, the Tillman FET pre is used as an impedance matching device, not really as a gain boost, and is used to reduce signal loss over long runs, or as a convenient interface with mic preamps.

    Perhaps what you want could be achieved by winding individual pole pieces with wire to pick up one string at a time (as with hexaphonic pickups), then creating a matrix of pickup coils between the neck and bridge, say 6 by 6, with a matrix of switches located below the pickup to allow you to turn each coil on/off individually.

    Phase can also be added simply with DPDT on-off-on switches.

    ..... this would amount to WEEKS of work, but it's just a thought.

  16. of course, the simplest option is to cram as many single coil pickups as possible into a bath-tub rout *(swimming-pool rout) guitar body, and placing a switch below each pickup.

  17. @Bertram... I only use the Strat as an example. I figure that at some point we are going to want to
    try out the concept in an instrument, and out here (USA) new swimming-pool-routed bodies are approx.
    $50usd with a finish on it. I'd hate to see you make up one of your beautiful designs, chop a big
    hole in it for the prototype pickup, and find that it isn't what you wanted. I'd much rather a Strat
    body be turned into firewood during the development process than one of your creations.

    Hollow bodies... hmmm.... never considered this. It really shouldn't be a problem. A traditional
    electromagnetic guitar pickup works on the moving-iron principle. As long as the strings are made of
    ferrous metal, we should be ok. (it wouldn't work on a classical guitar with nylon strings) The
    mounting would be different, and yes, an archtop would complicate things. Off the top of my head, I
    would imagine that the end-result would have a half-dozen production variations to fit guitars with
    different scales, dimensions, etc.

    The aluminum (or for that matter, copper) box wouldn't affect the electronics sound much. Aluminum is
    a non-ferrous metal, though the various alloys might have some varying influence. Potting the
    internals is done to reduce/eliminate pickup squeal. Potting is definitely a must with the pickup
    elements, but we probably won't have to goop the entire assembly.

    Pre-determined settings vs. manual dial-in... possible. Sounds like you would prefer a traditional
    tone/volume pot and some kind of pickup switch for the manual-mode portion. For the pre-sets, you
    would like a set of rotary switches...?? Some kind of a mode switch to go from "manual" to "pre-set"
    would be in there as well. This is my take on it, at least initially.

    The more you can describe what you want for the switching and other control features, the better. I
    see common themes with the controls in your sketches, and believe you have some definite ideas as to
    what they should do. These functions are part of the user-interface. I don't believe in creating a
    user-interface without a lot of end-user input. The controls *must* have functions that are
    immediately apparent to the guitar player, and work as can be reasonably expected. When an end-user's
    expectations are violated, the end result is often a failure.

  18. @Mike... I wasn't referring to Tillman's circuit, but rather his idea (which was completely brilliant)
    to phantom-power the circuit. Though I really like impedance-conversion to drive a long guitar line,
    it is nothing new. The phantom-powering just hit me in the face & I found myself asking why I hadn't
    thought of this before. With phantom-powering, we could put a rather complex set of electronics in
    the universal pickup package, and not have to worry about changing 9V batteries after every song.

    With a lot of independent pickup poles, that means we would have a lot of little coils. Small coils
    with small numbers of turns equates to low output level, and therefore something else will be needed
    to boost the signal to bring it up to a usable range. I figure each coil having its own active device
    to allow the individual pickups to remain isolated and therefore lessen adverse interaction of the
    elements. The more poles, the more transistors. The more transistors, the more current.

    The 6x6 matrix is an intriguing idea. The only issue I see is the same one you see: a lot of wiring,
    a sophisticated switching arrangement that would almost certainly require a serious solid-state
    switching array and corresponding computer-like interface to handle the presets and switch-pattern
    programming, and lastly some form of visual display to show which elements are active... I think I
    wore out a tip on my soldering iron just thinking about it! Still... it is an interesting thought,
    and one I toyed with at first.

    To make it manageable, I feel we will have to do it slightly differently & put the pickup elements in
    groups to make what amounts to 10 pickups that span three strings each, but placed at angles to form
    an elongated "X" or cross (drum roll, please... and we could call it the southern cross) along with
    some straight up-and-down elements covering three strings each. This could incorporate some blade
    poles and some direct magnet configurations, which is something I know Bertram wanted. I figure we
    could get at least 7 good switching variations out of this. We would have patterns for the
    traditional bridge/middle/neck along with the non-traditional ones from the x-section pickups. I'd
    like to veer away from 36 independent poles just for the harness complexity and the need to design
    digital electronics far beyond my abilities. We're also doing this with a mono output, so that many
    elements and combinations isn't going to buy us much. Would be a different situation if we were doing
    stereo/multichannel & could spread it all out.

    Using the above idea could help us avoid the active electronics, and keep the switching relatively

  19. I've been doing sketches of my ideas. Bertram, I'm probably going to scan them and e-mail them to you so you can post them. You have my e-mail; could you send me a test-message?


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