psw

@psw

Col's sandwich stack and my version deal with another issue, the big difference that exists between signal levels in driver and sensor mode. The combined sandwich drivers have a hum cancelling effect on the sensor coil. This should greatly reduce the interference of the decaying signal across the driver coils (right after the switching) with the signal across the sensor coil.

Well...could you expand on this aspect then because I'm not understanding I suspect.

To me there seems to be a logic flaw. If a driver is putting out enough EMF to move the string, any magnetic sensor is going to sense this fluctuating EMF resulting in oscillation or squeal, no? If the cancellation of the two driver coils is complete, then there will be not enough EMF to move a string surely? I can kind of see the idea of having the two drivers separated but my experiments in sandwich designs and similar things never could overcome this kind of intrinsic quality problem...

I'm not that keen on studying patents these days either, though the referencing of the Moog thing and not studying it for at least the 10 minutes it took to get the general gist of it and see that there have even with this information some false assumptions seems neglectful. The basic thing is much as I described and proposed years ago, sample and hold and activating things exactly as described in the "driver engine" idea so that interactions that they describe between close drivers and sensors are eliminated through the sequencing of activation.

However, they use "time" separation instead of the physical separation required in more traditional sustainers with sensors and drivers separated by space. This would eliminate interactions between sensors and drivers as they would not be on at the same time...except that any other sensor will just as easily 'sense' these driver signals just as in any other system.

What seems to be proposed is an attempt to run both sensor and driver on the same core simultaneously and that's where I just don't understand the logic that will overcome such seemingly exclusive interactive forces. I can see what col is thinking, perhaps having one of the drivers on top of the sensor it will still have enough effect to drive the string, this would remain to be seen, that from trial and error methods (for which I have been resoundingly criticized on many occasions) I have conducted it would not seem hopeful.

but you know, good luck

I think the moog patent needs to be studied a lot closer to find out what is actually being achieved and how and more of the finer details, the extent of what I read was washing over a lot of these details, the drawings perhaps giving a few clues...but there still seems to be a lot of assumptions with the "moog" thing...at least now there is something to study to work out what is going on there.

I'm not following exactly what the proposal is there FF and col. To me it would seem likely that the drive sandwich might largely cancel each other out and running the pickup and driver simultaneously would seem to be hugely problematic. If there is any EMF to move the strings coming out of the driver however it is arranged or the number of coils, surely this will be "heard" by the 'pickup' it is sharing the coil with and likely overwhelm the signal from the vibrating strings surely?

Also not clear as to what the goals here are. For the work and complexity, what is the pay off of it. I can understand the desire say to have a more polyphonic sustain across all strings, for that you are probably going to go towards a hex system, at least in the drivers but likely in the signal as well with a hex pickup system too. I could understand a desire to have a driver/pickup kind of thing that would allow a selection of pickups or placement of the driver in an unorthodox position such as the middle or perhaps the bridge. I certainly followed that kind of thing for a long time. But, if the end result is a mono device that operates and performs much like what can already be achieved through simple means, what is the 'aim' of the adventure?

Just trying to apply a little Ockham's razor to things you understand.

There is a perception that the signal must be taken at the same place along the string and there is some sense in that and of course the patents are strewn with such concerns for compensating for that and the qualities of the coils. But what has been shown again and again in the DIY versions is that it is possible to use simple means to produce the "effect".

There is room for "improvement" but I'm not grasping what the improvement being aimed for in these schemes are. It can be enthralling to be 'building a better mousetrap' but one needs to be clear to define what "better' is...I mean, if the end result is just that you catch a mouse, then in what way is the trap "better"?

I'd be interested to see how it goes and it has been done by a few people and in commercial guitars to some extent (the original jeff beck strat for instance, a PRS guitar who's name escapes my memory)...

A bit of this would be "experimentation" and as such you need to find your own answers. I have heard some positive stories and a lot of less than satisfactory ones.

However, there are many aspects to consider, one that immediately comes to mind is that to get a humbucker you must wire the pickup in series, reverse wound and reverse magnetic polarity. Having another pickup of a different polarity, or either polarity right next to the other will by necessity change the magnetic field and qualities of the pickups. A magnet of the opposite polarity will necessarily attract the field of the other for a start, regardless of any wiring.

Different HB's will have different qualities, many can sound quite good split but in general there is some compromise...

It is possible that you have not considered other options. Parallel wiring can be very effective as I recently found, completely humbucking but similar in qualities to a split. Another is splitting with a capacitor, a value selected to taste. This involves effectively cutting the highs out of one coil in a way similar to a tone control giving a "split" plus the body and bass of the other coil and some humbucking qualities as well. You can even wire a tone control to variably cut treble on one HB coil leaving the single Even a 'treble bleed' circuit on the volume controls can give a good result, giving a bright sound when the volume is turned down very effectively, and again full humbucking and noiseless.

Splitting a pair of singles a bit apart may negate some of the magnetic effects, but then consider how a pair of singles work in a strat when the neck or bridge is combined with the middle pickup. Generally a hollowed "phased" sound because of the physical locations along a string and so canceling frequencies. You can get an interesting HB like sound by reversing the wired phase of such combinations.

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Still am interested and making some plans for a future project, considering GFS lipstick humbuckers which are a pair of true single coil jangly pickups perhaps and maybe a rotary switch in place of tone controls to wire up different options.

My resent guitar has some unusual HB's, very high powered and all slug coils and they seem to sound very good in parallel and split and the two inner coils split even has a touch of strat quack to them...I prefer this sound to their more conventional series wiring as I play very clean these days.

So, it would be good to see what you come up with, but the results are likely to be a little unpredictable...

A lot of this kind of idea and what I seem to be getting from the Moog patent from a brief reading is that it is similar to some stuff I was doing during the hex era part of the sustainer thread. A lot was not gone into in that area as I was largely working alone and a lot of things were hypothetical till the basics were possible such as making effective hex drivers small and independent enough. I did discuss a few of these ideas with LK who was most active at the time...

Most importantly and similar I think to the way the Moog this works it would seem, was my idea of a "drive engine" circuit. The would appear to have both driver and pickup coils. I tested my hex things as low impedance pickups and they did 'work' to that extent though that wasn't the aim.

The idea of the "drive engine" was to address a number of 'issues' by operating each drive element separately and sequentially so as to avoid interaction. So, a sequencer chip would send a signal for a small time frame, then to another driver further away, then another and another, perhaps in pairs...with the momentum of the string carrying through the non-drive states. This is much as my present "limiting' things work too, saving power by shutting off when drive is sufficient.

So, taking this further, you could potentially sequence through sampling the string and then holding that to replay back in driver mode. There would be some complexity involved for the phase characteristics I would imagine as the sample and play would be in separate time frames, but it is possible that it would work even in a basic form.

Potentially it might work in a mono version, we know that the basic mono sustainer will work with an effective coil design without any phase compensation and very simple amplification. We know that it can be turned off and on to limit the runaway feedback option in relation to amplitude.

More complex would be to say have a circuit that could ascertain the frequency of a note being played (tuner like circuitry) then a sample and hold (sample that sound with delay type circuitry) then replay that sound briefly in line with the frequency to keep in phase...then repeat the process at reasonably high speed.

There are plenty of pitfalls, you need to set up a clock for the sequencer that wont introduce clock noise and fast enough to keep up with things so it will stay in phase, plus enough power to drive the string with enough momentum (though I don't think this is a problem as these things would ideally sample and play very fast)...and then there are the characteristics of the coils as well, there will likely be some backlash from the capacitance of the coils having stored energy and having coils capable of responding at a suitably high speed.

The "mono" thing is trickier still as the signal will be quite mixed and probably prohibit this kind of complexity, though it still may have merit. It would take a bit of experimenting, but already the DIY project has shown for instance the effectiveness of the 'piggyback pickup driver' for instance and so in that you already have a pickup and driver elements on the same core. From diagrams I saw, it would seem that there are both driver and pickup coils but sharing the same core, so very much like the "piggyback' thing in miniture.

My feeling on a lot of these things were to put it to one side, there seems little reason to pursue a mono source hex driver particularly when the effect can already be achieved by quite simple and conventional means. You would want some tangible improvement. However, if you could do it with a hex thing, perhaps even using the same coils to both sense and drive (though it would appear that the Mood don't do that) sequentially, then there could be some tangible polyphonic improvements from such a scheme worth pursuing.

It's one of those conundrums, you are taking a sample from the string in the same place as you are going to drive it, but then you are shifting that drive in time considerable. So, the advantages of 'phase' being sampled in the location are undermined by such a radical shift and going to require a fair bit of circuitry to deal with, this in itself may bring in delays of processing that will require compensating for...so a tricky enterprise. Plus, there are some fairly well know physical effects that will be occurring, the drivers will be inducing currents in nearby coils and affecting magnet and core materials, currents in coils will build up a capacitance charge and a polarity that will need to be "relaxed" or they themselves will be creating delays and inefficiencies.

The "driver engine" idea (like firing the drivers as if the sparks in a combustion engine was the analogy) was mainly aimed at these kinds of aspects, giving each driver some time to 'relax' before being fired again. The other side of the hex driver from a mono source was to perhaps condition the mono signal to be more biased for each string frequency, through filtering or driver construction itself, as well as for a more even response with different drive power attuned to the string it was driving for a better string to string balance.

I think if you are going to go that far and with such complex circuitry and seeking some kind of tangible benefit over the existing working simple technology, then you'd be clear as to what is being aimed for. To this extent you are likely to need to go "hex" completely.

In my own work, fairly early on we did set out some criteria to aim for, much was to not alter a guitar excessively and to retain the pickups and technology already in the instrument. I think that such criteria is vital so you can gauge direction and progress in a project. So, thing like low mod, battery operation, low mod (so small circuit boards), tangible benefits to adding more complexity, all such things need to be taken into account or a new set of criteria or aims set out to keep things in check and not running wild.

For a lot of my aims, it is not just an anathema to require an enormous amount of processing power to get a similar result as a more direct analog system as much as it is for me to require supplying remote power or a circuit so big that it wouldn't fit in the guitar. For my criteria, something like my telecaster fulfilled most aims entirely, compact surface mounted driver, no mods to speak of except for rewiring and a switch, compact circuitry, good power consumption, fitting the battery into a tight guitars control system. Plus, within the capabilities of DIY and no detrimental affect on the functioning of the instrument in its conventional role.

Others may have other criteria, I believe this was discussed around the 30's pages of the thread, but mine were fairly extensive. Lower on the list were things like improved polyphonic sustain and some more exotic functions and control. I had hoped in my hex work to make such significant improvements with an elaborate driver that it would justify the work and expense but I don't think that is necessarily so without far more put into it, rapidly outstripping my know how and being prohibitively expensive and undermining many of the core criteria. It was possible to make quite compact surface mounted hex things but to run them from a mono source in a simple form they were not proving any more effective than a single coil driver and exhibiting a lot of 'quirks' that were detrimental to performance. Mine were for instance, very susceptible to alignment, so they needed to be built for a particular guitar, but then what of string bending?

The more complex the system and the aims, exponentially complexities arise. It is even possible that some can not be overcome (a magnetic driver will put out EMI for instance), but regardless such things are extremely likely to break the core criteria I set for myself. And, in the end, many of these things will result in "one offs" for the maker, hardly heard and probably not repeated or verified by other makers...so not fulfilling the aim for a DIY project as such.

But, if you have a mind to do "it" why not. So, you might want to consider the idea of switching in an out of driver and pickup functions and investigate as a first port of call, simple sequencing chips.

One other advantage of the "driver engine" that I remember now is that you'd most likely only require one amplifier and preamp stage as with the basic sustainers as this too could be switched through and avoid a lot of duplication and power use...

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Anyway, it's a thought from way back in the early days of the thread before most people involved now were involved with then or perhaps heard of or considered. It would appear to be something of the jis of how the Moog people are doing it and that the square drive thing is perhaps (I don't have time to sift through things completely) is more about generating a signal to trigger and time the sequencing of pickup and driver functions and signals.

Most things have been covered here...

The fender story was kind of right, but in the bio I read that Leo had the idea that if the frets wore or something went wrong he'd have a side line and easier to simply unbolt the neck and put on a new one. The very first ones didn't have a truss, but alas, they failed and at least once at their showing, so truss rods were included...

They are an adjustment mechanism, yeah, steinbergers are made from super strong non-organic stiff material and molded to exacting specs. Parkers too are pretty stiff and have a kind of wire rod I believe.

Truss rods are necessary for adjustment. Classical's, sure some have reinforcement, but low tension strings and a substanial neck profile there...my classical is very good (Yari) but even that once needed "adjustment' requiring the heating up of the fretboard and regluing under a special press, so don't underestimate things there.

I think the whole "metallic thing' is a bit of mojo/superstition...maybe a bit of laziness at the thought of having to install the things. Most truss rods are not typically adjusted much after set up, many don't even know how to set up guitars, but it is important.

Even if wood is dried and true, once you start cutting and shaping thing it releases all kinds of unknown pressures.

There are guitars like martins that might appear to have no truss rods, but in fact have substantial reinforcement and can be quite tricky to work with when they move...

So, sounds like a bad idea based on a fallacy or supposition that isn't borne out in the number of instruments that do have them and sound great...and possibly motivated by something else entirely.

Making a neck with the right kind of curve in it under tension is an exact science, steinbergers might be able to do it, but the inconsistency of would is likely to make it impossible to predict and without a truss, no way to adjust for it. Then there is the changes in temperatures and moisture to contend with. Those old kramer aluminium necks were super strong, but once the stage lights heated them up they went all over the place and out of tune!

There is something to be said for a thick neck and certainly stiffness and mass play an important role, but you can go a little far with these things I suspect and there are plenty of other ways to add strength and stiffness to a neck regardless.

Huge neck is likely to be hugely neck heavy and need more weight in the body to compensate...these things are not necessarily 'desirable' or 'natural' or 'better' you know...

So all in all, even if you are going to stick with some notion that a truss rod is 'tone sucking' then you will likely need to deal with the consequences of that decision. I have never had a guitar that didn't move to some extent in it's lifetime or didn't need a truss rod to get a good set up even with a very stable neck and super stiff ebony boards.

No...there are lots of variations, but a traditional fender bobbin is as shown in SL's post and the bobbins are made of fibreboard, so effectively paper. Also, the wire is enamel insulated and excessive heat from the grinding may well heat things up melt and short coils and probably damage the magnets as well.

If a pickup has a integral kind of "magnet" holders...say like a typical HB bobbin, you can remove magnets or more correctly slugs and screws as the wire is protected. Some single coils are made in a similar way but you would have to be sure that this is the case.

The metal plate under a tele bridge pickup does tend to be a part of the sound of traditionally built tele pickups, it does effect the 'shape' of the magnetic field

I forgot that tele pickups have that base plate which is important to the sound and prohibits the 'pushing in" of the magnets to make them flat that I have heard of people doing with strat pickups.

I'd be taking SL's advice here and not attempting such a thing, maybe his offer to make a new one.

Alternatively, perhaps a radical angle of pickup adjustment might yield some good results without messing with it. If doing it as a paid thing, you are running a big risk of destroying the pickup and you will be taking it on yourself to be cutting it up.

I'd be seriously speaking to the client about options like selling the pickup and getting a new one like SL is offering that is just right, maybe better. If not and they get hacked, without the 'clients' permission, you'd be up for a new pickup and likely the cost too...plus damaging reputation and everything.

No...and why would you want too?

Real fender pickups are built from two plates for the bobbins held together by the magnetic poles with very fine wire wrapped around them. The magnets are a part of what holds them together. There's a fair bit of tension in a bobbin, especially on the insides and most likely wax sticking it together...

So...is there a risk...sure...most likely if you remove them you will never get them back if the structure doesn't fall apart anyway...removing them is likely to break the fine wires, but if not, once out the inner wire will be pushed in and you won't ever get them back.

I have heard of people attempting to simply push the magnets flat, say in a vice, but even there there is significant risk of breaking the vulnerable wires waxed to the magnets and bobbin.

Exceptions are potentially some cheaper copies that have bobbins molded with inner parts where the magnets are encased...but how will you know if this is the case, with a tele bridge pickup it's likely rare and this is a "cheap" way of making things so is the pickup worth doing this kind of thing to?

The other aspect is that magnets like alnico are very susceptible to demagnetizing with heat and vibration and the act of grinding and cutting...so even if you could get them out (which you likely cant) and you could get them back in (which is even less likely)...you are likely to severely damage the magnetism and have to have a way of re-magnetizing them again and matching them to the other poles...

Besides all this, if you are not aware even of how such pickups are constructed, and therefore ask such a question, I'd suggest that the likelihood of any success in such an enterprise to be...well, nil!

But again, why would you want to?

Edit SL beat me to it with pics...!

Hmmm...well this is more of the kind of thing I needed visualized and appreciate the work you have put into it...will give it more thought perhaps...

Diagram 7 shows some points of full cancellation and Diagram 5 shows that as you play between these points the nodes of lower order harmonics are always less than a quarter of their length from the second octave node. I have studied this in great detail and this occurs all the way up the fretboard

I know how long these things can take to draw out and wrap one's head around and I applaud your perseverance and how I can often come off as perhaps oppositional for the sake of it.

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There are some interesting ideas, some are incredibly subtle and more things are being introduced.

Recently I added a thick (3mm) aluminum plate to the headstock of my trem equipped LP and added these rollers which in many ways work similar to string trees (only sideways) and it had an interesting effect on the sound of the guitar...subtle but there. Such a mass provides strength and stiffness to the headstock, significant support behind the nut and mass to the head as well as making the length of string behind the nut much 'shorter' than normal. All these factors have a positive effect on the sound and makes the "vibrations" seem a little more "true" if that makes sense.

But I don't like to create some mythic mojo about these things. There is a positive effect on things and on this guitar in many ways for this simple mod. You can hear these things like adding mass to a head by adding a sizable clamp to the thing or pushing a head against something solid. The headstock is often a place where there is flexibility and highly susceptible to vibrations and can effect the way a string vibrates. More so than at the other end of a solid body guitar, trems also have these kinds of effects. But, you know I resist endorsing hard and fast rules as there is still some subjectivity in things. Some people actually like the noise associated with single coils and that this is 'part of their sound' for instance, I can't say that that is "wrong" (though I love a really super quiet guitar these days).

How a string vibrates is complex but some of this complexity is stripped away by things like simple magnetic pickups.

The sustainer in harmonic mode gives an interesting perspective as you can hear how the string driven at this point will produce different harmonics (say an octave+5th or 3rd or other subdivision) and kind of predictable and be ever higher, but then revert back to those of the first series from the open fret at the twelfth fret.

Another thing that I had been discussing elsewhere is that the harmonic series is of course at odds with equal temperament tuning and the guitar worse than some instruments. A sound high in higher order harmonics will produce tones within a note that are 'out of tune' with the note being played. It is even worse with chords and combinations of notes. I am kind of resistant to things like 'pure tone" and the mojo surrounding some of this kind of thing...

I think the main thing about the neck pickup is that generally it is in a position that will sense overwhelmingly the fundamental far outweighing the subtle harmonics underneath it, despite any cancellation effects. Locating the pickup closer to the bridge will lessen this effect, creating perhaps more higher harmonic content (not necessarily because of cancellation effects, but because the fundamental is less overwhelming to them). So, more distance between the bridge and the neck pickup will have this effect more. I don't know that the 24th fret is a sweet spot, perhaps the 22nd is even more, or the 20th, remember a lot of jazz guitars had less frets and had their pickups located in this kind of region for good effect.

The danger is that such conjecture is used as a marketing tool as if conclusive and that is something I try to resist.

There are a lot of factors that can go into things, pickups themselves can be fascinating. I'm glad you did an experiment to see that in a PAF say, one coil may be remarkably different to another and really skew results. But one of the 'smoothest' pickups I've had is a tele chrome covered skinny single coil...designed for this kind of 'jazz' like response and built deep and thin and has particular qualities unlike other types. A P-90 has an unusual magnetic array that is extremely wide as another example despite being a single coil. HB's will ahve different response from either coil generally, the screws being quite different from the core in the slug coil for a start and are often designed now so that one coil and the other mix to a great cohesive sound. Some old PAF's had this kind of magic because of the imperfections of the day and may have contributed to the mojo thing. Now we get mojo in aging of magnets and all manner of things. My natural tendency in such things is to ask more difficult questions to test such claims for validity, but there is only so far an amateur can go.

Anyway...I appreciate the effort, it is time consuming I know...

I think though for this discussion, though I agree that things are more complex than they seem in some areas, that things like pickup qualities or picking style is a little outside of what the OP is getting at. The assumption is of course, that all things being equal, for example being picked in the same way, the placement of the neck pickup has a "sweet spot" that relates to the harmonic series in the strings vibrational mode.

I do believe that there are far too many variables, different pickups with unknown qualites for instance being used on the test rig....but there are a few concerns...

But, what I am having trouble getting my head around is how these diagrams relate to fretting on any string. To me it looks as if even fretted on the 5th fret, the '4 wave harmonic' is going to condense up and be somewhat opposite to the open string. This is pretty much as I would expect, that when a note is fretted, the string length changes and so then all the harmonics must move along with it...however, the neck pickup, where ever it is positioned is stationary, therefore, it would seem obvious that as soon as you start fretting notes, the relative position of the pickup in relation to the string length and all the harmonics must move. It was brought up last time this conjecture was put forward but I don't see a convincing explanation of why it wouldn't do what seems obvious as the string shortens with fretting.

One of the problems is that it is a hypothesis that is put forward and a lot of drawings (that themselves are not really real world) that appear designed to support the conjecture...however these kind of obvious 'challenges' to the notion are not really "tested" and shown not to matter.

I believe that there is perhaps a preferential kind of positioning but it relates to other factors such as the distance between pickups and pickup types for instance.

One thing is that an HB format has a very wide 'window' and sampling a fair bit of string, it may well be that things cancel out if the node is exactly centered between two coils (though it isn't proven as such)...but with such a wide aperture, any deviation from centre could have quite dramatic results with this line of thinking as the string is shortened by fretting.

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An interesting thing is the way a pickup does sense a string and whether such things could be designed to pickup up more complex vibrations than it does in it's current format, making it more sensitive to picking technique and revealing more of the complexity, much as acoustic instruments typically do.

Not quite following that...but you know, may well be confused and it's after midnight. These simple divisions of open, 5th and 12th frets can be a bit deceptive.

However, on the fifth, all these wave forms move along and condense to smaller wave forms...so some nodes somewhere for instance, at some fret is going to to cancel that isn't going to be on a different fret...is that not so?

Not explaining it too well...but if you condense the 4 wave purple "open" wave from the 5th fret, surely the pickup will be more in line with the middle of the wave, not the nodal point...and so forth for other waves...so quite different than the open string...yet we don't hear 'radical' changes in tone as other factors are likely to be more influential perhaps.

Everybody's favorite game : 'I'm drunk on Friday night, but can I still operate a scanner ? '

Here. (PSW's looks better)

Hahaha...well nothing new under the sun...however...they didn't kill a plastic tortoise Like I did...

Since we are talking cool little ideas, I came across an idea in Adrian Legg's old "customizing your electric guitar" book the other day that had slipped by me. One of his guitars had active electronics in it, so he installed a "mercury switch" in it that sense when the guitar is 'upright'. So, when he is done playing, he puts it on a guitar stand and the battery is disconnected and the guitar is "off"...saving power and no noise from the thing sitting there plugged in with an amp on. (I suppose there is a jack switch as well so it is off when unplugged in it's case)...

Pretty cool idea, I always thought there must be a sensible use for the things maybe one day I'll try that as well...

Anyone else come up with or have come across little ideas that make a difference?

The nut on my input jack comes loose all the time. It drives me nuts. I never thought to just put a washer or a nylon nut there. Thanks for the ideas!

Yeah...I know, most plumbing supplies or hardware stores sell o'rings and they work a treat...for a vintage look you could install it behind the plate and you wouldn't know it's there.

Used to be that when you'd buy a 3/16" thick Wilkinson roller nut, it would come with a truss rod cover with 4 rollers just like you positioned them, except on the Wilkinson, the rollers were a little closer to the nut. Can't find a pic online, but there's a pic in the 90's StewMac catalogs.

I was not aware of that, though it is an obvious solution to the problem. I did see a New Zealand makers guitar, one of it's features (besides wood that is apparently 1,000's of years old) is a fender-ish head but with the 3 higher tuners at an eccentric angle and small rollers to guide them over and retain a straight string pull and double as string trees. Didn't use ball ends but I suspect they would work as well. I've sat on this idea as something to try, but not needed to do it till this guitar.

The placement of the rollers the way they are is purely an aesthetic thing, they could be right up close to the nut, but I like the way this arrangement arranged the strings and cleared the tuners still more.

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Having played the guitar a bit since this mod, and quite a bit before the mod, the tuning is now extremely stable with trem use, so that is a success...

However, I do think there is quite a noticeable difference in adding this quite big slab of metal firmly fixed up there...it is 3mm thick plus perhaps 1mm of plastic on top of it and adds a bit of stiffness and mass to the head and this vulnerable neck scarf join.

Such things have been offered before...

fathead

• More Sustain

• More Overtones

• More Balance

FATHEAD works on the principal that by increasing the mass of a guitar’s headstock increases the duration of string sustain. The FATHEAD effectively triples the mass at the headstock which dramatically increases sustain, extends tonal range and eliminates all “dead spots” common to most guitars and bass guitars.

FATHEAD lets the string ring out louder, longer and with better balance.

FATHEAD was invented and patented by Aspen Pittman, owner and designer of the famous Groove Tube Amplifiers.

This doesn't go as far as that perhaps, or at least I'm not pushing the claims...but it does seem to affect the sustain and overtones...I played this guitar a few weeks without the plate and a few hours since. I wouldn't want to overstate the effect of my 'plate' but I do think it adds strength to the join being located at the top rather than underneath. Also, it is very stiff but being aluminium very light so not risking making the guitar head heavy...the rollers may well be like string trees on a fender and dampen vibrations behind the nut (you will notice that with locking staggered tuners and no string trees, on an LSR and fender head they still needed to put in tiny rubber dampers behind the rollers to stop these on strings with a fair bit of length behind the nut)...

The end results are...

• that it covers the truss rod adjustment
  
• Is decorative
  
• Fixes the tuning stability with the rollers and trem
  
• provides reinforcement to the vulnerable neck scarf
  
• the nut is supported but a substantial still mass of metal
  
• It's light weight but stiff
  
• Adds mass and stiffness where needed and so exhibits a bit more sustain and overtone balance, much like a stiffer neck or adding mass to a headstock does...
  

The only 'down side' is that behind the nut bends are more difficult because the plate is quite thick and you need to push the string much higher than just behind the nut...I actually do use behind the nut bends a bit for harmonics, but I guess that's what tele's are for

One reason I have an interest in this and perhaps observe some of these things from a different way is because such aspects have always been of importance and observable from the sustainer project....consider this...

As on my guitar here, the driver is as far away from the source pickup at the bridge and drives the string electromagnetically.

The phase of a string where it is sourced and where it is driven is of concern of course and there is a lot to the ideas.

Further though, if you reverse the drive signal, it will dampen the fundamental and drive the next strongest harmonic (although there may well be more to that also)...

What you find is that as you shorten the string by fretting, different notes will produce different notes in the harmonic series derived from that note...indicating that things change as you fret the string...

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PAF HB's will often be intentionally wound with one coil louder than the other. At the very least the qualities of a slug coil and screw coil are generally different because of the inductance and resonances that are different between coils. I suppose a test would be to reverse the pickup and see if the better sounding coil is the louder one or the one in the position designated as "sweet"...

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I think you have a hypothesis but for really getting any conclusive data to make a theory from it and not simply set out to prove mojo with still more...you'd need to plug your test guitar into an oscilloscope and spectrum analyzer (you can get free software versions) and put the time in to really learn to understand what you are seeing there.

The drawings of waves is all very well, but they are not accurate, only to illustrate a point, in the end they are not "real" but made up.

I found that the tillman thing to be surprising in that there were things about the wave form I expected to change as the string was shortened in much the same way as things changed when the pickup was moved, yet there seemed to be something 'not quite right' going on there either. As you say, and I didn't read it all, it too may not be accurate but demonstrate the principle from theories of vibrational movement of a string. Obviously a real string is very complex.

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(Quoting the webpage)

"Now consider the 4th harmonic which has nodes at the 5th fret, the 12th fret and the neck pickup - there is no 4th harmonic vibration over the neck pickup. This strong difference in harmonic levels plays a major part in the unique character, or timbre of this pickup.

A way to prove this is to play this harmonic by damping an open string above the 5th fret (making sure not to pluck the harmonic at its nodes over the 12th fret or neck pickup). You will hear almost nothing from the neck pickup, but a strong note if you switch to the middle or bridge pickups"

Yes, but one can surely see that this applies only to the open string, shorten the string (by fretting another note) and everything moves to the right while the pickup remains stationary. At the 12th fret it will hit the next node to the left as it moves up perhaps. Therefore, the notes played in the 5th-7th fret area may well have the opposite qualities to the open string...no?

Similarly, and it was pointed out years ago on this forum to me by someone, if you fret the very highest frets of a guitar, you are up real close to the neck pickup and it will be offering up similar qualities as the bridge pickup situated always near the end point of the string down by the bridge. So, you see, as you fret surely everything changes? If so, there can't really be a particular "sweet spot" except in relation to the length of a string which is ever changing.

This, as before, is still the thing to be answered, no amount of making up of hypothetical harmonic lines of open strings is really going to be convincing, neither will physically moving a pickup around a string on a real guitar. What needs to be done is to set out to disprove the theory as hard as you can to see if it holds up...and so find some surprising results that perhaps we haven't seen. So, you quote tillman about the 4th harmonic not being sounded, and this is "sweeter" to you...ok, does that still hold true for any fretted note, at what stage is this no longer true? These are the kinds of test that really show rigor and will be convincing of the theory, not just the stuff that supports and idea that you believe to be so.

Thanks, I intend to do a thread on this guitar, it is becoming my main guitar after the tele but still needing some tweaks...

I modded the kahler with this thumb screw that will lock it to fixed with a couple of twists...

You can see the tortoiseshell theme in the pickups so the truss rod thing is in keeping with the "look"

It has some innovative electronics hidden in it too, 22 pickup selections with 4 push pull knobs but the guitar looks very business like.

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The ability to lock the bridge and avoid the locking nut opens up a whole new avenue to explore...but I'll keep that under the hat like this idea until it is shown to actually work...

btw the thumb screw idea only works really with this stud style version as the flat mount the hybrid locking screw is too close to the body...shame as it is so much better than the allen key grub screw that is used

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To replicate this approach, I used rivets as the axles...here is a pic...

All ball ends are a little different...the rivet things were a great idea as they look neat and there is a bit of a pinch just below where the roller would be at the 'head' of the rivet pin to hold the rivet on. This will ensure a tight fit in the hole and locks tight in the aluminium. The bass is kind of think, but the added mass does make quite a bit of difference and adds strength and looks good. I quite like the 'flow' of the shape with the way the headstock curves out.

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I have tried to work on details for my guitars, here's an idea I don't think I have shared before that works a treat...

A suitable "O-ring" provides a really neat non-slip washer to avoid any possibility of the jack socket coming loose and even provides a tiny bit of 'spring' to it...looks cool too!

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The idea these days for me is to try and come up with lots of little details to make up a superior whole rather than get embroiled in years of development of one 'super' idea...I think it is paying off much better these days!

It's not all words and typing you know...just occasionally I actually work on the darn things...

In fact, this worked out so well...I'm already thinking of a and even collection parts for a sister to this one...we'll see how the future Kahler mods thing goes.

I'm still trying to get my head around Tillmans app and what I am seeing there, interesting stuff but I'd have to investigate more, perhaps ask some questions regarding this. As Tillman has done much of this work it seems, you didn't think to contact him with your own questions to try and 'disprove' you idea (which along with a methodical approach, is the scientific approach to ensure as objective conclusion)...

Playing with it there seems very little change in the frequency spectrum with moving the neck pickup position or fretting notes...hmmm...which leads me to think that perhaps I am misunderstanding something, or misinterpreting what the applet is showing me.

I notice that in your diagrams recently produced show a nodal point of 8mm...how did you derive at this figure?

I don't recall which coil was "coil B"...I have had splits on my LP you decades and my new guitar and like the "inner coil" but not because it is necessarily "sweet", I just like that sound. More important, and where position matters a lot, is the the combination of coils...this can be demonstrated in Tillmans other applet...and this is where some real 'magic' can be had. I almost always play in the combined pickup combinations to get the kind of sound I generally require. I play very clean as a rule so I need some complexity, I also use a lot of harmonics and require the neck pickup for the "body" and the high end of the bridge pickup for harmonics...but just generally, you get moe flexibility with combining multiple pickups, so this is perhaps where there might be a "sweet' spot, at least to my ears and on a particular guitar.

But, as Till man suggests, there are other factors at least as important...the window size, the resonances of the guitar, the qualities of the pickups...so many variables that effect things and likely more important in total than the asspect that you have been working on for a long time.

Thanks...

I did think of a roller nut but rejected it for a couple of reasons...

One...like the LSR on my tele (which would be even better than traditional rollers, but again not suitable for this guitar) a "roller nut" would have to be moved forward in the nut slot so that the 'axle' was in the right place...so a permanent mod cutting into the fretboard so a gamble...what if it 'didn't work'?

Two...the "ball end rollers" would need to be modified...the lower strings would sit "proud" of the rollers (though these could be filled in a drill perhaps to a V to match) while the higher strings would be 'sloppy' and I wasn't sure if I could cut 'slots' in them without going right through to the axle or severely weakening them. How did you manage to avoid these problems? (any pics?)

Three...a teflon or graphite nut is pretty darn slippery and looks a bit more "traditional"...not sure that a roller nut on a single axle is going to be any "better" really...but it's the 'side pressure' that's the real killer (try pulling the strings in like my rollers do and you will get an idea of the tension put on the side of the slots of any nut with splayed out tuners like this...)

Still...they do work really well in this application and I might be tempted to use them in a nut or other application next time...hmmm

Well...I seem to have succeeded with this idea...

The guitar is a LP project I'm working on with a Kahler trem...

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"The Problem"...

The Gibson style head pulls back at a fair angle (also a weak spot) and the strings also pull quite a bit to either side with the inner strings.

"The Solution"...

Firstly, Sperzel locking tuners in satin chrome (matches the knobs)

A big truss rod cover made from 3mm aluminium and coated in some thin tortoiseshell (the tortoise and satin chrome is a bit of theme on this guitar)

I built rollers out of the ball ends of some old strings and the shafts of some rivets...these will press fit into the holes...potentially the plate adds mass (and so sustain, etc), supports the nut and adds strength to the thinnest part of the neck.

Here are the parts and roughed out plate...

Anyway...the nut is a new white Tusq XL and is teflon impregnated. The tuning has been fairly stable (especially considering the nut is still not glued in while I'm tinkering with the setup and action) but certainly not 'good enough' and no comparison to my LSR tele...however, this 'solution' is a significant improvement.

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So...the basic idea is that these very smooth running rollers take off the side pressure from the nut meaning that it only needs to deal with the straight pull...much like a fender, the lean back eliminates any need for 'trees' of course, but do put on a little more 'pressure' on the nut...

Mostly though, I like to add something unique to my projects and find some solutions...particularly if they look good and in this case I think it also adds a little bit of "bling" to another wise 'plain jane' head. The 'decoration' is a thin stainless steel bit of jewelry that I found and filed off the chain attachment and stuck on with double sided tape. A guitar just looks odd when the head is "blank"

This "solution" may also be helpful even if a trem is not used on any guitar that has side pressure on the nut slots, this is the prime place that 'hangups' occur when tuning or even bending strings.

Designers might consider the use of ball ends as string rollers (say for a DIY roller bridge idea) or for more 'outrageous' headstock ideas that have some more radical splaying out of strings from the nut.

Thanks Ansil...

Well I am interested and will need to do something with this LP to get a better tone for my purposes I suspect, at least with these high powered pickups. They can sound a little boxy and certainly overpowered though split well. I did a full on 4 p-p wiring scheme on it, so it will be a bit tricky to 'mod' further, but am considering adding in some components to tame these pickups a bit more.

I use the middle position most of the time and that is where the 'magic' happens quite a bit...with a bit of fiddling between teh treble bleed and tones and combination of splits and such, it gets some of the effect you are describing but to find it can take a bit of fiddling about...

I am thinking of doing another with different pickups on it down the line though and hope to get a bit more of this kind of 'sound' for the fingerpicking jazzy stuff I'm doing these days...so who know, perhaps I'll give it a go there.

cheers

As I said earlier, I'd be aiming to test the electronics or at least wiring it up outside of the guitar before committing to things, especially when it comes to 'sustainers'. It is not a magnetic sensing device there but en electromagnetic output device...like a transformer, nearby coils can't help but have currents induced in them by the driver.

Even the close magnetic field of another pickup nearby could have a detrimental effect on the device, and especially the sustainiac 'bi-lateral' type drivers. This is one of the reasons in my own sustainer drivers I ahve not pursued these things more fully. I have played a sustainiac guitar and was suitably impressed though and the neck pickup doesn't sound too bad, much like single coil strat pickup.

There are more 'sounds' to explore as well compared to those you have gone for. With working on my latest guitar I was suitably impressed with the humbucker in "local parallel" (local as in parallel with itself) giving a noiseless single coil type sound. My guitar also has "global series" in it which is interesting...this puts all 4 coils in two humbuckers into one huge HB and gives a thick tone that is a little "jazzy" perhaps and slightly louder as you might expect. The interesting thing is when you combine this setting with things like phase between pickup...notching out some of that "thickness" or running the bridge in parallel while being globally in series...so many variations are possible.

But one also has to be practical really I think, I know I have been overly guilty of far too many options and still do, but you don't want things to be or look to fiddly IMHO. Although my new guitar has 22 different options from 2 HB's all are hidden in push pull pots. My tele has a sustainer and a phase switch...the 'drive knob' hides the harmonic option and the volume the phase in 'hidden' push pull functions.

Yes, 'local phase' tends to be very disappointing and nothing like say the bridge and middle phase thing. In fact, on my phasocaster strat (which also had the first DIY sustainer of mine) I had phase switches for each pickup in relation to the other, this had the effect of reversing the quacky notched sound of the strats 2 and 4 positions to be more HB like...so it was kind of counter intuitive in a way but worked well. When I eventually put in the sustainer to it, one of the controls could not be used as before which was a middle pickup mixer control though the phase switches could be overrided...so there are limits to the switching capabilities that are practical and the guitars sustainers can be used with.

I've not wired up a sustainiac nor know the options possible, it seems a lot more adaptable than a fernandes system though...it is very different from my systems that typically were designed to allow a lot more flexibility as far as wiring and pickup choices and such...but that's not to say that theere wouldn't be a way, but it is going to take a lot of nutting out.

If you draw up a schematic or have a clear idea of what you want to do, this is perhaps more of a job for the guys over at the Guitar Nuts 2 forum....their main aim is creative wiring mods...

Hmmm

You know it wouldn't be hard to test the components to find out the values, including the pots and coils with the right equipment and know how.

What you seem to be suggesting though is that the publicly posted scheme featuring two HB's and component values is not in fact the scheme that produces this result?

you can't drop this one i did into a hum bucker setup it just won't work the same.

Yet this seems to be exactly what you presented in the initial post is it not?

The Torres engineering pots with lrc circuits claim much the same thing, a strat like quack or acoustic like response...even the acoustic simulators that are quite convincing are simply analog filters...but are quite a bit dependent on the pickups and guitar they are in for the response you can get.

Sorry to be a bit 'skeptical' but it does put one of trying things when all manner of other contingencies are not stated. One reason I did not look more closely into this which occurred as you can see just prior to the wiring of my LP is that it seemed a bit 'fiddly' for practical use...far better had the filters been set up as an adjustable thing that could be switched in to produce the 'effect' than the balance of pots and the reliance of unspecified pickup qualities in the circuit for example. However, it does one's reputation no good at all to present things that will not produce the results or results that are substandard by presenting specific diagrams that in the light of these comments, would seem to be false?

It would be great if you could get a sound clip of the thing...I'll need to study a little more how it functions and if my scheme could perhaps be modified a bit perhaps.

These things are hard to get credit or reward from, but good luck with it and good forethought as well. Have you seen torres engineering's little transformer and tone circuit on a pot to give a more strat like 'out of phase' sound...they produce something of a similar effect in a way

Hmmm....well, sustainiac warn that very complicated wiring schemes and such may not be possible with the sustainiac, so you need to take this into account.

With the sustainer you need to have only the bridge working and it probably won't like it being 'messed with' as a signal source (such as putting it out of phase or in parallel) when it is being used as the source signal.

Also, nearby coils such as neck and middle pickups can have currents generated in them from the electromagnetic energy coming out of them from the driver. In my own sustainer designs at the very least (but I'd suspect not much difference from the sustainiac) this has meant lifting both grounds and hots of all other pickups completely from the circuit.

The easiest way to try and deal with this I've found is to find a point in the wiring scheme, generally after the selector and before the controls, where you can insert the sustainer on/off switch. In mine (which are different considerably as the whole thing is off and the driver not used as an active pickup as in the sustainiac stealth versions at least, when switched on) I use a 4pdt to switch out everything, this will usually be done with two poles hot and ground, and reconnect the bridge pickup directly, and witch the power on. However, I don't know what the sustainiacs requirements are as it may preamp the entire guitar and at least the neck pickup when not in sustainer mode.

So, yes a very tricky scheme to solve there, best to draw everything out extensively and get a feel for all the connections on the sustainer to work out the function there. It could even be that not everything is possible with such wiring schemes and I have read much to that effect on their site, or that such things would cost a considerable amount for them to install if possible.

Best of luck...

Oh, phasing an HB 'locally' sounds quite a bit different from spaced separate pickups. If you have the guitar made, you might consider wiring everything up on a bit of board so everything hangs out of the guitar and you can play with and modify options...it is so much easier than trying to work inside the guitar and you won't have to commit to any hole drilling or anything till you know what works. You should end up with a 'harness" that you can wire straight into the guitar....

Here's a recent guitar I have been working on, an LP with 22 sound combinations from 4 p-p pots and a standard selector....