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Novel Guitar Wiring Idea need technical advice PLEASE

  1. Jun 21, 2012 #1
    Hi Everyone,
    I appreciate any useful feedback and advice on this project as honestly it has become the bane of my existence and a real downer everytime i look at my half assembled guitar. Guitar? yes guitar and I know one might be tempted to dismiss this post or just refer me to the myriad of diy guitar and or stompbox forums; many of which I'm a member; yet alas I've had little sucess with them and Only end up more confused majority of the time.
    The cause of my predicament is my own damned ambition ( coupled with a lack of technical knowledge and experience). The wiring on my SG Epiphone needed replacing and the compartments needed shielding.
    easy enough, one would think, and it wouldve been except i bought another higher end humbucker pickup to install and decided I would have 2 humbuckers and a single coil pickup but I then became fascinated by the different wiring combinations that achieve distinctly different tone from the guitar eg: all series, all parallel, some series some parallel, split coils, single coils, different caps, vari tone selectors etc. I could go on 4eva as there are hundreds of different ways to wire a guitar. My problem was i got greedy I figured that there must be a way to isolate each coil of each humbkr and along with the single coil pickup I wanted to be able to take the two wires that lead from each pkup and connect them to a type of selector circuit that could connect the pairs in all the different combos w/ separate volumes and a varitone. traditionally its done with switches and/ or rotary selectors and/ or push pull pots etc. What I really want to know is can i use my arduino to route the analog signals in all diff. ways and combos and possibly scroll through the settings with a mom. push button? Or something like it? I was looking into little ic based relays and analog muxs and demuxs and digital switch ics but I don't have the experience or expertise necessary to design a circuit to achieve the goals I related above. Can an Arduino just handle the switching between connections while leaving the audio signal from the pickups relatively unchanged and remain analog? Could it also be used to act as a bit of a pre amp or booster so theres no chance of signal loss from the complexity of the circuit?
    I have two arduino compatable boards at hand an Uno and a Leo-stick usb thumb drive style board.
    If you have other solutions possibly simpler or more elegant or using completely different tech Im interested Im prepared to discover that Im miles off track and I need to buy different parts to finish this project.
    Thank you for reading through this short novel of a post I hope you were able to glean the gist of the issue and can at least point me in the right direction to research it.[/b]
  2. jcsd
  3. Jun 21, 2012 #2
    I was a guitarist for many years and I am currently designing electronics for electric guitar. Let me tell you one thing.......

    I am going to answer your question in two point of view:

    As an engineer, any active electronics in the signal path inside the guitar will change the sound of the guitar. The impedance of the pup is more complex than people realize. The normal volume and tone pot set up an impedance load to load the pup. That together with the capacitance of the coax form a load that make the guitar sound what it sounds. You put any active electronics in the signal path, the sound will be very different and sound un-natural. Actually I am spending 12 hours day to write and file a patent application relate to guitar electronics that deal with this. Hopefully I can file it by next week.

    Before I really get into guitar electronics, I thought they are just that simple, but the more I work on it, the more I find the subtleties. I yet to be able to put any active circuits inside the guitar and still make it sound anything close to a bare pickup circuit. Not even close.

    There is a good reason why after all these years, people still stay with the good old simple passive pickup circuits. All the Seymour Duncan Live Wire, EMG active pup. Fender Elite Strat or even Eric Clapton signature strat never gain main stream acceptance because of this. All the dime a dozen DSP, fancy electronics never gain any traction. As time goes by, the more people going back to the most primitive configuration.

    As a long time guitarist. I can tell you, you make your sound. Sound has everything to do with your skill, your technique....the way you play, the way you plug the strings. That's more important than anything else. Most of the sort after sound by famous guitarist like Hendrix, SRV, Santana etc. are played with very simple configuration, mostly just the single neck pup. You never find any sort after guitarist that use complex combination of pups or electronics. It is the guitarist that make the sound.

    I have been on the Fender Strat talk forum for a long time, my user name is alan0354. All you hear is people bought the Fender new S1 switching that give what you are asking for, all the fancy combinations, parallel, series and all. Guess what, there are so many threads about people changing out the S1 switching. If that is what you want, look into the the Fender S1 switch on ebay, people getting rid of them like plague.

    It took me years to get my own sound. Instead of wasting time looking for some fancy sound, practice, feel the sound that resonate with you. You know when you get your own sound.
    Last edited: Jun 21, 2012
  4. Jun 21, 2012 #3
    Yungman is right.

    The pickup operates at the quantum limits of thermal noise. Adding anything like an active crossbar would destroy your tone.

    It's odd but every good instinct a EE would have for improving the guitar signal chain ends up ruining your tone.

    This happened 60 years ago when Leo Fender sold his company to RCA, a firm at the Acme of audio and RF tube engineering. They destroyed the tone by making improvements to the feedback and power supply. Totally justifiable engineering improvements.

    The electric guitar and amplifier resists all attempts at science and engineering to make a better tone and ends up relying on 70 year old techniques and technology for the best sound. It's very much at odds with direction of all of modern electronics.
  5. Jun 21, 2012 #4


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    Please go back to SIMPLE and if you want to make changes, make them them incrementally, if at all. Your guitar's electronics should be simple and clean. It is possible to have both humbucking and single-coil pickups in a guitar, but it is harder to balance them than it might seem at first. Get back to SIMPLE and stable operation, then baby-steps from there, if you want changes.

    I made a lot of my pocket-money in college (over 40 years ago) buying up and fixing electric guitars that some misguided individuals had "customized". Most times, it was a matter of getting back to the original configuration, then tweaking to allow for added/replacement pickups to work properly. Not a big deal.
  6. Jun 22, 2012 #5
    I forgot to talk about the moment push switch to cycle through the effect. That is a bad idea. It sounds ok in theory and maybe use it in the living room when you tinker with it. When you are on stage, you don't have time to think where your setting is and what is the next one. You only have a split second to change sound.....AND at the same time, your attention is with the progression of the music and what other members are doing. You'll get lost in 5 seconds.

    All too often, I play clean rhythm and jump into one line of over drive solo with different pup , then has to switch back to clean rhythm right away. It will not work with your push switch at all. You have to push many times to cycle back to the original setting. This is all from real stage experience.

    Let me give you an example, the good old effect pedals that has a foot switch. If you chain up two or three of them, you'll quickly lost track which one is on and which one is off. That's the reason why people put LED on the pedal to tell whether it is on or off. I am designing pedal also, do you know that LED cost almost $5 at cost to put in? You have to use a 3 pole double pole foot switch that cost a lot more. Pedal builder has very good reason to put it in even though it cost so much extra and don't do anything to the sound. Anything that simplify the switching and switch fast is about the most important.

    My guitar setup is very simple, on my Strat, I have individual volume for each pup, so I can play rhythm with one pup at low volume setting, then flick the switch to another pup in full volume and step the foot switch to change amp at the same time to run a solo line and switch right back. It is all about smooth seamless transition.

    I have HSH ( humbucker/single/humbucker) in one of my Strat. I have individual coil splitting for both humbucker. The two 3 way switch sit in between two of the volume pot. I can choose the north coil, hb, and the south coil by the switch. I just use the standard strat 5 way switch. With the individual volume control, I yet to find I miss any setting. That's all the setting I need.
  7. Jun 22, 2012 #6


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    you might consider wiring up a pickup backwards and using that with the frontwards-wired pickup. you might get some interesting sounds.

    BTW, the tone of what you hear from a guitar is a combination of many things, including the pickups and combinations of pickups and the guitar amp. the various impedances (which are frequency dependent) play a role in how signals are added when your pickup switch is in the middle, but since there are pots on each pickup (usually a volume and tone pot), that contribution to the output impedance will also affect it.

    i would disagree with others that none of these complexities of tone can be emulated with DSP. i think that's what Line6 is doing, or attempting to do as well as emulate the effects of the amp. we're not there yet, but your pickups, the tone/volume pots, the combination with the other pickup, the effects of each stage of the guitar amp (including things like the output transformer if it has one) and and the speaker and enclosure, all are doing signal processing mathematics. we just don't know what all the mathematics are. if we did, and if the math was small enough to code into DSP code, then we could emulate the tone pretty well. but we're not there yet. that's why you still want to get an amp like a Mesa Boogie or something like that.
  8. Jun 22, 2012 #7
    Human ears are so much more sensitive that any instrument can measure. Human can hear minute little difference. Never mind about complex signals, I yet to be able to get a true clean boost of the guitar signal.

    What I meant clean boost is one that I can increase the output of the guitar, but sound absolutely the same as the bare guitar. That's sound really easy, any op-amp can do it.......that is until you try it. It sounds nothing like the normal guitar plug into the amplifier. I tried compensations, I tried transistors, I tried them all. I even try to introduce even harmonics and experiment with the sound. I tried putting the op-amp into class A by using a pull down resistor to make the top NPN do all the work and never turn off to get rid of the crossover distortion. Anyone has any idea, I love to hear it.

    Yes, if you can truly decode the frequency response, you might be able to simulate, but it has been years people are working on it. The more the technology advanced, the more people are going back to the vintage guitar and amplifier.

    I can truly say any electronics in the signal path between the guitar and amp changes the sound. It might sound funny as the guitar amp comprises of electronics. But it is. Bare guitar has the kind of "raw" sound that got lost if you put any preamp in the signal path. It just sound processed......for the lack of better words.

    To OP, there is a site that actually post different wiring for guitars. It is an Ibanez site, they have a special 5 way switch that give you a lot more combinations than the standard Strat switch.


    They have a sticky on pickup wiring.
    Last edited: Jun 22, 2012
  9. Sep 5, 2012 #8
    From your initial account, it is not clear what your fundamental requirement is. Personally, I would rather have just one exquisite guitar sound than a thousand others that are non-descript. There are many ways to colour the sound outside the guitar, but they are unlikely to be satisfying if the original source isn't satisfying.

    The selection of the pup load capacitor and resistance are the most critical parameters. Together with the coil inductance, they set the resonant frequency and Q of the circuit to give the tonal characteristic - from smooth jazz to piercingly brittle and all subtleties in between, or in the worst case just dull and lifeless (when the coil is loaded too much).

    The problem with coil switching is that the inductance is changed each time you switch. Unless you switch the load cap/resistance values at the same time, it's unlikely that you will be satisfied with the resulting sound. So one great sound and a bunch of mediocre ones.

    Take a simplified example for a humbucker: Parallel = 1/2L, Series = 2L, North/South Coil = L.

    Add the fact that the North/South coils differ slightly, and that you have to factor in cable/amp capacitance - connecting the optimum load capacitance becomes a bit of a problem. Now add two more pups and you have nightmare!

    I have just finished wiring up my Vintage V100 with two new Trevor Wilkinson pickups (he claims that Seth Lover, inventor of the HB, gave him the mystic runes of how to build the sweet-sounding, original versions - actually I bought then because they were cheap ;) ). I can switch between parallel, series, north coil, south coil, and magnetically out-of-phase (on the centre toggle), and I have a different load cap on each pup.

    I can only play the rhythm pup in series for a few seconds before I have an orgasm. The OOP is really great for Peter Green too, but the rest of the configurations are just ok.

    It took a lot of spice modelling and cap swapping to get there and after all that work I want to:
    - rip out the switching and configure the pups in serial only
    - rip out the both tone controls and replace with 12 pole switch with a range of caps

    Having spent so much time soldering in different caps I now realise that with a 12 pole switch and a bunch of load caps i'll have more tonal choice than a kid in a sweet shop :)

    The moral is pretty much the same as everyone else has said. Hope that helps.
  10. Sep 5, 2012 #9
    You can make highly refined DSP models that are versatile and flexible especially in a live environment. I used to gig with a guy who had a nice Line 6 setup. Very versatile and I'm not knocking the product.

    But the bottom line is this:
    You'll *never* get a Line 6 or any DSP-based amp emulator product to sound like this all-tube signal chain in the link below. This is what to-die-for tone sounds like. It's not the only excellent tone out there but I've personally never heard better. Every ounce of the sound is 100% musicality with no unwanted sonic properties whatsoever. It's downright sublime.

  11. Sep 5, 2012 #10
    I am hot on the trod in tube amp. My stupid Marshall JCM900 blown on me a month and half ago, that force me to pull out my old Bassman 100. I since gutted the preamp and redesigned a dual channel of my own. I have been studying tube electronics. Here is a text book I found very useful that you can download if you are interested:


    I have been busy studying this book and designing my own amp. I think I got my preamp, I want to design my own power amp and make it my own product. So far, I am doing it quite different from traditional designs.
  12. Sep 5, 2012 #11


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    You should pick up a copy of Dave Funk's "Tube Amp Workbook". There is so much useful information in there....
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