psw

I was going to suggest an audio interface, but clearly you have one. Not familiar with that one, I have an edirol UA-25 that is preamped and limitered and even midi... But, perhaps your guitar isn't putting out enough gain...is this the kind of interface that takes instrument inputs, or designed for hooking up RCA plug things like a CD player? If so, it may well be loading the high impedance guitars so some kind of buffer will help or fix this mismatch. Most stompboxes, all Boss pedals for instance, have a buffer in them even when off...so if you plug into something like this, then from there to the interface, you will create a buffer and match the impedance expected by such interfaces. If you have some kind of compressor pedal, these can be useful anyway, takes out the peaks that can spike distortions. Digital distortion generally sounds pretty bad, it's not like running tape into the red to get a warm squashed effect...it becomes harsh and abrasive, so you want to keep digital recorded signals way out of the red. It's not clear what you are monitoring the computer with, headphones are generally good, but if listening to stuff with computer speakers, the tend not to cope too well with running an instrument like a guitar into them...guitar amps are of course quite different to plugging into a stereo system, they are built to deal with such signals...sometime the monitoring system just can't handle what it's trying to reproduce. It can drastically affect recordings if you don't hear what things really sound like...that's why monitoring systems for DAWS are so incredibly expensive. Decent headphones though generally give you a good idea of what is going on though. Good luck with it... pete

ArMelvin1 Sure...not sure how long it will take...have sought advice elsewhere, there certainly are ways to make these things work of course. I added a typical "buzzer" piezo element to the wood below the bridge...in the spring route. This is the same for either Kahler model, but potentially applicable even with fixed bridge installations. There are numerous circuits and installations about, typically for strats...here and elsewhere So...I put the piezo on the wood below the bridge as I anticipated adding it to the bridge itself might make a bit of spring noise. I found a smallish cheap preamp kit, so will be working with this as the basis...all piezos will need a powered buffer or preamp of some kind...this one I have used for the sustainer project and should fit the bill. I also anticipate, and in line with previous work on these things, that they wont sound that great on their own. So the plan is to have a mix only, probably with a preset volume on the piezo with an internal trim pot...and just pull a pot to add in the piezo to the body of the mags in any selection...give it an acoustic like percussive edge in mono... but we will have to see, perhaps the whole guitar may need to be pre-amped in order to effectively mix things...I hope not... So, this is my new project and direction. Not taking away from ansil's contribution though...there are a huge range of sounds available from most guitars and the tone controls are often neglected. If, like most, you don't use tone contrls at all, you may as well explore some of the "extremes" and see where they lead. Rmember a cap or resistor only cost a few cents...so, for a dolar ot two, you can get a fair amount to play with... For my project it is a bit ore complicated... Piezos require an active system, there really isn't a way around that. Electric guitars are not acoustic guitars, this is a given. However, there is a middle ground I believe. A simple piezo system should draw little power, if nthe whole guitar need not be preamped, it should last for months, if not, well it will still last a long time if un-plugged when not played and add the benefits of an active system. This project is a little unusual, it will feature coil taps and a few other tonal tricks to get the most out of it. I(t is for a particular musical project that requires a clean sound and some variation...so not your typical guitar. And as well as the electronics, there is quite a bit to do yet in the set up. It was intended to be a sister to the tele I built a while back, then put on hold for a long time. I now realize that I am incorporating a few behind the net bends into my arrangements and a locking nut may cause problems...so, beyond the electronic side of things, a bit of thought will have to go into the set up and some practical solutions... But for sure, I am really keen to have this thing work and a plan that can be replicated by others easily and relatively cheaply and to good effect...when the whole thing gets working, I should even be able to do a few sound clips. But, as I say, it is really to put a bit of a percussive acoustic edge to things....none of this stereo or full acoustic kind of aspirations that you might expect from a "ghost" of "fishman" kind of system...but I am hopeful that it will be effective and useful, cheap and low mod....

Again as has been mentioned many times, this is NOT TRUE. I'm afraid the criteria has and been repeated for many years... The so called "secret circuit" only appeared two years ago, not long before everything was closed down and before that I have used the CHAmp and PreCHAmp circuits and a whole raft of alternatives many photographed, some using chips that have since been recommended... A bit of "poisoning of the well" logic amongst others, I didn't recommend the F/R that has continuously been attributed to me...that would be outright plagarism to pass off these mash up circuits as ones own...yes, just like Hank did with his chip and tillman and most other things proposed...but then it is not that much different than many circuit I used and got results with for years...a buffered LM386 circuit...I stated that is what I was using, G-mike came up with the F/R solution, no one else bothered to come up with their own. Yes, but as you have stated since joining this forum, you have sought a completely different response than I have and your posted sound clips sound completely different in many ways...so each to their own... Many people clearly have built these things to spec with success on their terms and I have posted my results and what the thing sounds like. My criteria for "success" is not achieved by drivers so big that they prohibit a neck pickup, require a lot of room for circuitry, have to plug into an outboard power supply and a range of other ambitions discussed years before you guys turned up in the Hex era...so, in fact THIS IS TRUE. It is worth noting that the continued lurker HmcS had the same tone and ridiculous suggestions to promote elaborate hex systems and the like, only to settle for something remarkable the same as what I have been doing with the simpler things all along, and then trying to sell the things! When challenged about the piggy back driver thing...he builds one remarkably similar to the kinds of things I dhave for years, and originated in concept...oh, and that works too!!! I have suggested that any number of small amplifiers can fit the bill, that as far as cheap and easily obtainable the LM386 fits the bill and has shown to work over and again...but I am not going to endorse the F/R in it's present form or even promote my own circuit as "the solution" when there are clearly so much animosity and it is against my beliefs that there is even one "best circuit" or my circuits alone are the kind of things that work... So...now...out of nowhere, you say you have made an F/R with a 100uF output cap and preferably the mods I described for it, and a driver like mine that I am only too aware that someone like you could have done in 10 minutes with materials you are known to have on hand, able to test it with your own new inductance meter and get direct comparisons with your own work...yet you want to pressure me into some crazy dance about inductance figures? Are you suggesting that you were unable to get a response on all strings, that the thing does not work? No, it does not fit your understated goals and criteria. You have never considered it important that the guitar have any more than a bridge pickup, I've seen no work that even shows how to implement such systems. So...you don't like the response of these things, it's not to your taste? We'll each to their own really, there is no "correct" response to things...is there a perfect distortion pedal, if I promoted such a thing would anyone not eviscerate me for making such claims? There is obviously a misunderstanding on my question about the action and qualities of the load...not the load (simply in terms of inductance)...of single coil and dual coil and even hex coils...but your argument screws that to simply throw a few mocking 'unobtanium and uranus' shots...helping no one and again threatening any threads on this subject...clearly a good tutor there, well done col! I would expect that a two coil design with say two 16ohms of wires, many, many more turns...to have quite different resonant frequencies and interactions to a single coil driver...I spoke of the "load" as the driver the circuit is designed to drive, not just reduced to the things measurable on you inductance meter. So, it would appear that this new found measuring devices main purpose is to imply that because I don't have one or don't work in the McS approved manner (that ended up with a remarkably similar solution regardless) is largely to show up my inadequacies on technical terms and "hard data" and not to forward the project at all or actually produce something convincing in the time spent mocking me and the work so far on those grounds. Well, hope that this is the acceptable result of such expense and time on the project, for me it was to actually create these things, but this impetus seems to have long ago become a side line to this "main event"... I know, and common sense will show you, that magnets in close proximity will interact...they will attract and detract...so with electromagnetic fields...so the interaction of multiple drivers will generally result in a different thing...the question is whether such things as you put forward could be expected to have a difference... I've not added the McSeemian shouts...but the reality is that the typical posters have tended to not stick to the formulas and basic procedures for making any driver, they have attempted to pot coils in playdoh and run 20 watts into them to compensate...a huge amount of the original threads were trying to convince people that these things are not the way....spawning a host of latter day detractors who claimed that people generally had problems with the actual project...oh, i couldn't get the buffer transistor so I left it out, I had pickup wire so I used that...does it matter if I just tie the broken pieces together...come on col...these are the typical posters of late, are you seriously saying that suggesting that someone goes straight in to winding a dual coil driver without any explanation about wire gauge or coil values and how to wire them to the appropriate load is some how better than my specific instructions given for a working basic system? So...yes, typical posters do give the impression are lacking in some of the skill set and expertise to make this successful in it's basic form, let alone some glib...I'd make a dual coil driver but I won't tell you how, response for which I made that remark! I still stand by it also. It may be "quick" but I do spend a lot of time trying to encourage people to stick to something that has shown to "work" and for which they intended to embark. It may not meet your standard...but then, what is that standard and how do you know what you seek is what others want. Al S started a thread recently that seemed to seek a lot of what my systems typically aim for in response...almost the opposite of the pure fundamental sought by you. Neither are wrong...but as far as criteria goes, the reasons for dual coil systems in conventional applications was originally and primarily to address EMI problems...if a good compact single coil driver can adequately cope with it and meet the range of other criteria I ahve marked for my own success...then that is enough for me. I don't build to your criteria, I can't even assume what they are, but I have made mine clear and consistently worked to those aims. The single coil systems so far...and before that the ultra compact hex systems that were smaller...were the best ways I could come up with to achieve that. Also, I have made dozens and dozens of these, I have had them independently verified and even endorsed by an american custom maker on a spare no expense guitar having never met me...and it met the criteria sought there too. I sent a hex driver and explanations to LK who confirmed that the things worked and the principle that was suggest was breaking the "laws of physics" was in fact sound...but then I got this same language back then because the 5 LED's in some of them were assumed to be the things driving the damn strings. ... Ok...so you have some work in the works? Some amazing new driver and circuit are going to be presented that is going to blow me and everyone else away? I'm so looking forward to it...but I have not seen anything like this in a very long time. Those who suggested I was being unfair to Hank should have a good hard look at the end results for all teh hyperbole and abuse...no hex drivers, no innovations for all the scopes and measurements and a years of arguing and abuse of my work...he comes up with a single coil driver and a basic amp and a plagiarized tillman front end...couldn't even design an amp circuit from scratch, let alone purpose built for the thing...and yet, as one might expect from something based on a known design (copied even down to the 5 LED's from 2005!) it worked. And, when challenged about speaking about the piggy back driver that "couldn't work" he makes one in a day and it does work...however of course, the same argument put to me now, right here, and in much the same way...oh...but not to my unspecified criteria. Oh well...when I see something come of all this, when a full system is proposed by anyone else and fully disclosed...well then, I'll be a happy man. If it can not accommodate my important criteria (leaving the functioning of the host instrument in tact) I will probably still be desirable of a compromised system that gets the job done. Of course "fancy AGC's" and the like that I appreciate you have a huge investment in, are necessary to get the kind of response you apparently desire...but they are not necessary for infinite sustain on all strings, blooming harmonics, harmonics on all strings or any number of the things the systems without these can and do achieve and been independently verified again and again. Though I greatly admire your own work col in this area and always cite and deffer to you on such matters, or indeed the patents before you, your desires and biases for 'how these things should be', your apparent subscription to the old "perfect sustainer myth", your non consideration of peoples desire not to have extensive mods or loss of pickups or to desire something other than what you consider to be "acceptable" does not mean that those who have made a successful simple driver, yes even with the F/R, did not find what they created was not acceptable...TO THEM. I'm not sure where this new round of vitriol towards me is coming from, but I suspect more would be gained if you simply put these words into practice and blew us all away with your version of how things should be and acceptable to you, explain why, show how it is so good that it justifies the space required for the circuit or the loss of something like a neck pickup...and then spend countless hours coaxing the typical poster on the matter that playdoh is not acceptable, don't wire circuits together with winding wire, and defend yourself when they fail and blame the project of the guitar that these naive attempts are attached to...then come up with the big reveal...oh, so I rand 20 watts into it and it still didn't work. These are the "typical posters" for which I speak, and I ma not overly quick about it...I have spent years discussing the same things over and over again...yet exactly the same things are repeated adinfinitum. And then the myth that 'it doesn't work' is perpetuated in mocking tones without any qualification (are you suggesting that the thing did not sustain, or just not to you acceptable unstated criteria?) by people who should know better and frankly do know better than that col. So, time to put these theories into action, state clearly what you are aiming for, and present how you achieved the "ultimate sustainer" and watch as people line up and suggest they wanted or expected something different!!!

Interesting ideas there ansil...I am all for playing the wiring by ear and trying some unexpected values. I did an unusual kill switch a while ago, you could swithc in a cap of a specially selected value to provide and extreme passive tone switch...sounded a bit wha like rather than just killing the thing. ... I'm about to embark on my own LP project, not sure I want exactly this kind of thing...but it will have 4 push pulls on it, s who knows what it might turn into...hoping to perfect a piezo on the kahler... but I'm looking for options as I hope this to be a special guitar and replace my tele as my main guitar...sorry sustainer fans...no sustainer technology on this one! None of my guitars contain PCB's though

FF...where does the arrow from between the two coils go...perhaps you could explain what is being achieved here? I have found as others have reported to, that things like the zobel network are important. Tweaking the values though may well produce improved results. Originally, I had even used an LM386 with an output cap alone and got things working (the original single coil drivers and ansils sustainer mod are this basic) but I did find that if using the things at high gain, and in line with the data sheet for such applications, a cap between pins 1 and 8 and from 7 to ground does help...in the CHAmp thing I originally used, these were all 10uF and have had no reason to change from those values. Point taken FF, my only real query about the drivers is that is there a difference in the values of things such as the zobel with different output caps or indeed radically different loads...ie drivers. So, what may be expected to work with one type such as a dual coil system like yours or cols...may not be the same for single coil drivers such as the ones I typically use and is most commonly made. As is often the case, or my failure to communicate this, it was taken as an advocation of the single coil design over dual coil designs or personal bias. It seems to be a common theme that if I use a circuit I believe it is "best" or that the LM386 is the bees knees, or to ignore that some people are working with different criteria for their projects. In this regard, for years my criteria have been publically listed...these criteria are at least as important an influence on things for me. The LM386 has been at the forefront of circuits because it is so simple and cheap and available everywhere...and somewhat adaptable. This is not the case for other options often spending weeks obtaining a similar chip for $15 than say $2 at a local store for an LM386 here, parts for my more recent circuit ahve been increasingly difficult to obtain as well, and very tricky where I now live...though I dare say I'd still find an LM386 about. As the public project has advocated the use of such simple circuits that are obtainable to the average DIY'er the LM386 has persisted. Anyway...will be interesting if people were to try out this zobel mod on an existing simple sustainer and see if it makes for an improvement...

Yes...well it has been suggested before... I recently got an offer from another forum to do exactly that and am considering something of that kind of move after recent events. There are a whole heap of issues in this regard...the old way as this grew was to simply keep everything in one thread with satellite tutorials and threads on completed projects...hence the driver making, the general tutorial, the sounds thread....and a few scattered threads that took the best of what was happening in the big thread to other places. Attempts to suggest that people make their own threads about their own problems and questions seem to have fallen largely on deaf ears...though perhaps things are improving. SO, any thread, now that the general discussion thread is closed, becomes a general discussion thread or hijacked into ever growing discussions not related to what the topic was about. This of course makes all of this stuff impossible to search for. If anyone has been following things or read posts in the last year, they can hardly be unaware that all this has led to the closing, editing and removal of almost every sustainer thread, and a general 'had enough' attitude of PG towards any sustainer topic being mentioned. However, any google search for sustainers, particularly DIY work, always leads back to PG. Over the years many fledgling forums have approached me privately to take the discussion elsewhere due to the overwhelming subscription...I thought PG was it's natural home and community, but after recent times, one has to wonder. The main thread was absent from view completely for a good part of a year, causing a huge amount of people to either wonder why google was sending them to PG or contacting me directly...any comment on the situation risked and indeed closed threads. Some of the misleading material was closed I see and just dumped into the tutorial section as a "solution"... So, I don't know...separate threads might be a good idea...but since that tends not to be done as a rule with people taking onto existing ones, and the huge thread that was never intended to grow like that is so maligned...it tends to be that people or PG just wish the sustainer things would just go away, is difficult or unmoderated, and the whole thing seems to encourage a lot of aggressively held opinions sometimes deteriorating to personal abuse. As I am seen to have "started all this" I seem to be held up for responsibility. The same impression seems to be that since I started working on things and promote them for others to do the same, I should somehow put the work in to design circuits or acquire the tools and skills to 'prove' my work instead of others 'disproving' or better yet...simply improving things. Anyway...has been for some time in recent times a difficult subject and environment and I am not sure that anything much has changed there...people who have contributed to that situation, and of course myself, still are here and much I have reason to suspect is transferred between those that were a part of this through PM's. In the shorter term, I thought that if people started their own threads and presented their work...if there were that many threads of interest a section may well evolve from it. People seem reticent to do that, and the all in one option is now closed. Also, since people seem to have trouble finding the tutorials and attempt to read the sustainer thread (which was never the intention and not a good idea IMHO), a separate section may well get as lost as the reference section where such things live. I've no objection, but the idea has been rejected for some time byt the power that be and I don't sense any change. It was years before the sustainer thread was 'pinned' itself....coming and going in the general section as things transpired. If people would like to discuss a potential alternative 'home' they are welcome to contact me, perhaps there is a more appropriate place for such things than PG, though it would be regrettable and continuity would be lost...

No...I was not advocating one over the other or any direct comparison, just that the various types seemed to be quite different animals. It is not about the numbers and measurements that I have already conceded to you, but the action of the driver with multiple coils and magnetic polarities...ideas about "throw"...opposite magnetic rails tend to be attracted to each other for instance... But, I am not anti- multi coil devices...remember I'm the guy who spent a year pursuing six coils and 12 magnets and such. I advocate the present single coil design as a good entry level and working device, it does the job. I have not heard that a multicoil design that was significantly better running from a simple circuit, I have not heard of side by side tests with the same circuit and guitar...things that I have at least tried to do. Much of the original ad vocation of multicoil systems were to address EMI issues, however, it is possible to build single coil drivers that do not suffer badly from such effects. My experiments in such designs were in an attempt to use such qualities to push the boundaries further than what the single coils designs can't do...like a mid-position coil. To justify the size (and all that typically entails like guitar mods and or losing the neck pickup) of a multicoil driver, it would have to exhibit necessary qualities that the single coil lacks (not related to circuits, AGC and such) in order to meet the criteria of overall success that I demand for my work. The neck pickup is vital to much of the things I use my guitar for, often combined with the bridge pickup, and I just can not justify a dedicated guitar to produce this "effect"...the reality seems to be that this is less important to others active in the project at an advanced level. So, I cant see how I could commit myself to a dual coil system...add to this that they are at least twice the work to construct...and I would have to see and hear some significantly better performance over a single coil compact design under the same conditions. I do think though that they need to be developed further and a 'formula' presented as to how to build the things before I personally advocate them to the kinds of posters typical here. I understand you new directions, but I don't know exactly what you would be advocating for people to replicate your results, particularly with the skill set and expertise that seems evident. The idea of dual coil systems have been around for quite some time now after all, but I have yet to be convinced that it is "in fact" a better way to go at this point or that the costs are worth it to someone like me. But, looking forward to be proven wrong... I appreciate your efforts with your new found inductance meter, and that some valuable improvements like the subject of this thread will improve things for any style of driver, but I simply don't have nor am likely to engage in a number crunching war about it. That you have given measurements for the driver typical of what I and others make, I assume you have actually build one and measured it? But the real crunch comes with testing such devices side by side and objectively annotating the pros and cons...it might "work better" (not sure what the criteria for this is) and it could be skewed that way, but I have to consider a lot of other factors. I hear someone proposing huge digital circuits and six amps and plugging the guitar into a wall...and I just shudder...my criteria is quite the opposite, compact, low impact, no loss of pickups, cheap, replication, desirable, works... As for my circuits, I am sure that you can and have made far more sophisticated compressor circuits, but I have used elaborate limiter/compressor preamps for years and years as I was reminded by a recent old photo that predates me even having a digital camera (back then that technology was rare and there was no reliable picture hosting which accounts for a poor record of what was actually bing done. The pictorial for instance was the first thing I used the digital camera for). I know it is "compressing", I can hear it and I used established principles when it was designed. It is clear that presenting it will do nothing for anyone and only attract more criticism of my feeble attempts with a lot of hyperbole, or indeed, just modifying it and calling it their own. I find it remarkable that except for a few notable exceptions, for all the words and such, we are still talking about the LM386 and that no one really has come up with a better basic amp for people...obviously I am no0t the one to do that, especially as the competitive spirit is such...but also, that many people have made a huge deal of their expertise but in the end come up with virtually the exact same thing, also with faults, that has been around all along! So, I think after all these years, and present company partly excepted, it is time for some others to step up and prove their devices and advocate for their features in line with the pros and cons and costs involved...as a total project, not just a single pickup dedicated guitar with any amount of space for circuits and such...these are the things I have always had to design around.

For the tutorials, look at the electronics reference section. Also, search out primals LP project from years back...he would a driver onto one half of an HB with complete success. The other half could be used as a single coil neck pickup, but he reported the strength and sound was rather low, so didn't bother as I recall. Even made the circuit small enough to fit in an HB selector cavity! Some things are a little tricky to understand in your posts...the main thread is likely to confuse, it was an ongoing discussion that ranged widely over many years...check out the tutorials, the driver winding one shows the essentials say of potting and winding. I'm not sure what you are saying here...have you already wound driver coils? It sounds like you ahve measured the pickup coils, in which case, the wire is all wrong and you are likely reading 8.4K ohms...that's 8,400 ohms...vastly different from 8ohms. Few will have the correct wire on hand...for dual coil designs, I defer to cols specs...

Oh well...out stripped my technical terms and my ability to concentrate with the flu I've got. It does indeed "compress" and "limit" the signal, and was based on known designs for that purpose, hearing it with a speaker does show this effect. Not sure if you consider this AGC. Anyway, the thing is an improvement, but still nowhere near perfect. The last I heard of you system col it was an effect that seemed extremely "mild" and controlled, but that is possibly the effect you were after. I am sure that a lot more could be done and you are right of course, unless I up the output cap value I am not going to get a true bass response and so drive. I'm not that concerned about "fixing it" at this stage. I have not heard, nor quite understand, except by biasing the frequency response of the circuit through filters (much the same effect as my dirty output cap solution) where you have low end fundamentals with high end harmonic bloom...sounds cool though. Not sure about it being wrong that it improves high end response...that is the reason to change to lower values...the higher output caps did not produce adequate drive and quickness of response at any gain levels, it was not to even out response of over active low strings, though this is a positive side effect to a degree. Lower gains will make the fundamental sustain longer on the low strings before blooming. But yes, I have always described my circuits "AGC" as a very simple thing that is defeated anyway by high gains and until switched, it leaves the zobel as per a standard typical amp. This is of course why I am confident that this project can "work" with simple circuits and the LM386 circuits remarkably well. The LM386 is not the "greatest" thing to use, but with SMD's taking over and all kinds of quirks, it has been the best and most versatile that I tested...I am sure there is better 'fidelity' to be had if one has a mind to search them out. Quite a few have been doing this including me and still there seems not to be a match to replace it in this application or general small amp designs...witness things like the "noisy cricket" and the "gem", "Ruby" and any other number of 'designs' floating around that use it. You don't find an equivalent with any other chip in terms of usage. Anyway...looking forward to trying this tweak one day...my designs have always sought to be as small as possible...at around an inch square, I could make it a little bigger, but this compact size has always been important to my criteria, just like compact drivers and I personally am unlikely to go or have the ability to go to a vastly more complex or larger design. Will be interested to know what you guys come up with though. I do wonder though the influences of the drivers as well, both FF and cols are dual coil systems and I expect quite different from the simpler single coil drivers I have generally used. I noticed quite a bit of difference with things like both my bi-lateral and compact rail drivers...seemed to need to be extremely close to the strings in comparison and not to drive things as hard though the circuit and guitar remained identical.

Yes...reading these posts again... I didn't want to get into that whole discussion about why the harmonics are not then canceled out and a chain reaction of ever increasing harmonics are generated. There are a number of factors at play...the circuit may not be able to have the fidelity to produce much of a cancellation effect at such high frequencies, the higher harmonics will be progressively lower in the mix, the physical location of the source and driver might be a fairly big factor. I'm just glad that in general it does not. Perhaps, with an ideal situation you would produce a muting 'anti-sustainer' with the drive reversed...it was something of an amazement to find that the harmonics could be generated by connecting the signal, drive or magnets back to front!!! I do recall having problems with high harmonics...till I realized that the strings were vibrating, but the amp I was testing the thing on could not make sounds so high. As it is a harmonic on the very highest frets can be almost painfully high...think of the old EVH horse whiny kind of effect that was popular for a bit...holding such notes might set off the neighbors dogs! Some of the quirks of this device I'm actually grateful for myself...that it works at all is enough for most!

No...I do...just ignore the filter Basically you can hard wire the pickup directly to the circuit, with the buffer on there, it will not load anything down when it has no power. I can see this was not exactly clear in this switch diagram, so my apologies. I believe in more recent versions, I used the negative of the battery to switch the power and this allowed the use of the spare "pole" to switch out the circuit...it is essentially the same thing though. So...take wires directly from the pickup's hot and ground so that when the selector is switched out and the bridge pickup reconnected, the circuit is still/remains connected also. I can see the diagram is a bit confusing and the "poles" of the switch are in a different order. See if you can draw a bit of a plan and we can trouble shoot it if you like...take the switch as the guide maybe EDIT... Note the "preamp" is just the fetzer part of the F/R circuit...on my older designs the preamps were separate from the power amp sections...none of the guitars signal to the output goes "through" any electronics or preamps...the idea is to be able to switch between the normal guitar, and bridge pickup only, lift the grounds on any other pickups, and reconnect the bridge pickup and turn the power to the circuit on...as long as it does this function, it does the job. If you want an LED, wiring it to the circuit will make it light when the circuit powers up.

Thanks col Yes, as I say, I mucked around with output caps to get a good drive on all strings...100uF has been consistent, but with the symptoms of low end bloom described. I realize that this biases the circuit towards the treble response and so has trouble sustaining low end fundamentals in any mode (the harmonic mode produces another harmonic in the low end). I meant, does the output cap have an effect on the zobel calculations you present? Yes, my stuff does tend to be a compromise, hopefully towards a 'decent' outcome. I do see it as a 'feature' but am not hyping it up, just explaining the limitations of what it does and how such simple tweaking can even out the response across strings say...less active predominant low strings, powerful drive in the high strings that more matches things. The g and b strings can get lively, but not too excessively, you just need to learn to "play" the things differently...don't hit them so hard, use the power to good effect, dampen as necessary. But the real trade off was to work towards a decent out come that filled the other criteria I set for "success"...approachable DIY technology, adapatbility of design with low mods to the host instrument, smaller size...given the different guitars and applications I ahve applied it to and that the driver and circuit are both 1/4 of the sustainiac...I do see it as something of a success. Having to put up with this "feature" to have achieved it is fine by me. With much bigger caps, the high end can struggle (the source pickup can have a difference though to the high end response of course). ... "My Circuit" is not that "magical"...it really just takes the established blocks of the things I had been doing, so a basic buffered LM386 but when the output across the zobel network exceeds a certain level, it triggers a diodes threshold and turns off the input. Some capacitors slow down the rate at which the source signal is turned on. All of this then is attached to the zobel network effectively I suppose, but only when the thing automatically turns off for a bit. If the level of the strings still vibrating through momentum is still too high, the thing will remain off by recharging the caps for another cycle. If the "drive" control is set to a very high level, it would appear that this cycling is effectively defeated or too fast to have any appreciable effect, at lower levels more so. I had considered that perhaps a similar mechanism could be used to switch through different output caps or be frequency sensitive and therefore "fix the feature" of low string harmonic bloom in the fundamental mode...but it really doesn't bother me and may make such a circuit overly large for my criteria. But I am sure that we have discussed a lot of these detail at the time I was designing them, and certainly some of the circuits that influenced the design. It is nothing like as elegant a solution as the circuit you presented col, and in truth acts much like the more basic circuits most of the time. Oh...and I know I don't have the knowledge and equipment or the nature to model these things in my head, to 'tweak' the parameters towards a workable solution, I ran the things through a speaker so I could hear the cutting off of the AGC as a kind of tremolo like effect...I just took the values that seemed to give a good result when hooked to my driver design and made them fixed. The only onboard control is a trimmer to adjust overall gain to below squealing...on the tele interestingly enough, it can take the full gain. ... Yes, my guitars exhibit a very natural "loud guitar" kind of response...that also was the kind of organic sound I was looking for. Often, particularly the low strings, if they are humming along and everything is controlled, the device can sound a little 'sterile' for me...but a fortunate coincidence I suppose. I am not sure what "problems" you are referring to...distortion? I am sure that people who know about circuits, obviously far more than me, can derive the principles I came to on my latter circuit, maybe do a little better...the AGC thingy does seem to give a slightly better battery life and I suspect perhaps a little less distortion (at lower levels) for a similar effect as if it weren't there...but it is a very simple thing. Again, it is a credit to the LM386 how easy these things are to work on that you can do stuff like this, output caps, zobel networks and AGC's and such can be constructed to suit pretty easily even with 'doofus' methods like mine. Of course it would be easy to add a switch to alter the output caps and thereby create different responses perhaps...I have been avoiding these kinds of overly complicated controls for my own use. I suppose this is something of the nature of the Floyd Rose patents switchable caps phase correction circuitry that could be looked into for guidance on getting an even response. ... I am not sure how important it even is for people to drive the fundamentals either you know...clearly I am not overly fussed and people seem to be attracted to the harmonic and blooming harmonics feature or sounds. I can see how it might be important to some though, in a different musical context than the things I use it for (to simulate a very loud guitars response in most cases and create predictable harmonics) it could be important to me also. For others they may be seeking completely even fundamental polyphonic sustain of a chord, for me 'that might be nice' but it is also cool to hold a chord, play the higher strings, clean and natural without sustain and have the lower notes gradually morph into harmonics above the chord. I am not sure that you can have 'everything' that this technology can do in one system, or that it is necessarily worth the efforts for most peoples uses to aim for some of these more difficult responses. If a simple mod of the output cap provides a better string response and a 'feature' of multiple blooming harmonics in the lower strings, I am kind of content with that myself as a 'decent' solution.

You know...I can't remember...a lot of stuff in this guitar wasn't tried completely....an awful lot was, the whole guitar was virtually hollowed out and there were a lot of various mods I tried in set up and such. The piezo thing was working in test mode but never built into it...eventually I wore the guitar out and had to get another testing guitar. It may have been some kind of sustainer experiment by the look of it...but I really don't know, just realize it isn't in there. I just found it as an example of a guitar with a few wiring twists...I actually had to compromise the original wiring to make it work...the mid pickup mix control had to come out as I recall...just not enough switching for the sustainer or something. Sometimes there has to be compromises, even with carefully laid plans...still better to have a plan...I even colour coded the wires as I recall. The "sustainer strat" had a separate cavity routed into the back so I could tinker with it...all the sustainer stuff was kept clear of the guitars wiring, I even routed the driver leads through the trem cavity as these can put of EMI...also good to twist or braid these wires to limit the EMI potential...but maybe it was the cheap pickups...in the tele the circuit is hidden under the bridge HB and causes no problems. Anyway, I'd just study the switch diagram and see if you can work out the functions as they might appl to your guitar...maybe post something to be sure. Remember though, test everything first before drilling and committing to things

Good Tip Col...the zobel does seem to be important, some have tried to leave it off I checked what is in mine and it is a 10 ohm resistor and a 0.1uF cap...plus the 100uF cap that also bridges from pin 5 to the output...I wonder if the value of the outpuct cap has a difference as well... I admit I just used the values that were working from the old CHAmp kit days...fairly standard data sheet stuff...so no science in the choice other than it works. 10 ohm does seem very close to 8 ohms though but that is a bigger cap you are suggesting. I may attempt this next time I build this circuit to see what the change of sound is...might be a valuable tweak. Another reason to like playing with LM386's...sop tweakable. good work!

ok...I'll see what I can find...there may be stuff in the tutorial on my guitars...check out my tele also for some compact wiring much as I do now... Here's a bolck diagram of the original "sustainer strat"...with some extras I had in mind. This guitar was used for ages to try out all kinds of mods and wiring things plus the sustainer... It's worth doing a more complete plan like this...but still, again...build and test the thing before getting to carried away with installation and such... The harmonic switch is obvious...any phase switches on the bridge pickup can have the same effect, so on my tele there is a phase switch on the neck pickup, on the sustainer strat there were phase switches on all pickups...but all of this wiring was bypassed with the sustainer on/off switch below... This is still pretty much the way I tend to wire things up on a guitar with more than one pickup...or simply completely disconnect the selector and all pickups with such a switch. So...to the left the first two sets of poles work to "lift" the ground and hot of the middle and neck pickups and short them together with the wire bridge at in the top poles. The third set of poles disconnects the bridge hot from the selector (connected to the middle and lower poles) and connects it to the controls and the circuit...effectively the bridge pickup can be hard wired to the sustainer circuit, it will have no effect till it is powered up. The last set of poles simply connects the battery power. More recently I have tended to switch the ground of the battery (-) rather than the positive (+) as you can also use this spare pole as a ground lift. There are quite a few variations that you can come up with, however the basic functions need to be attended to. Lift the pickups and pretty much all the selector and things out of the circuit...that means grounds and hots, not just deselecting the hots like a selector would. Connect the bridge pickup to the controls...it needs to be auto selected regardless of selector position...when turned off the guitar will return to whatever position the selector is in. The signal to the circuit needs to before any controls. With a guitar with only a bridge pickup, which seems to be popular with sustainer people...col, FF, etc...all you need do is hard wire the circuit in, and all the switch needs to do is turn on the power...very easy. Generally a 4pdt switch will work to turn the thing on and take out the pickups and stuff...but seriously weird wiring is going to take a bit of work...you need to lift the grounds and some guitars will have ground loops all over the place to the shielding and such. You don not want to lift the bridge ground or the shielding, but the pickup coils will need isolation...so often there will need to be troubleshooting required. A plan like the one I drew up for the sustainer strat then is a must for just about any guitar and worth the effort in building it, and if modifying it later. ... You may also want to think about ergonomics...you do not want to accidentally switch this on...on my tele the switch is protected back between the drive and sustain control knobs, the drive control has a push pull switch to activate the harmonics. On the sustainer strat I used two toggles below... So, out of the way but easy to reach back and turn on or activate the harmonic switch. I tend to use a blue indicator light that is clear when off...lights are entirely optional...you do tend to know when the thing is on! hope that makes sense and helps...pete

I notice that these threads quickly get way off the question asked...as the original thread was too long and all in one place, that people could not find what they were looking for, perhaps this situation is even worse. The original poster her for instance has only ever made one post on this forum, the first in this 4 page thread...and while things are interesting and all, it is effectively hijacking the thread to tack on their own projects and questions and thoughts only loosely related to it. So, given how far this thread and the others have strayed and the criticism of the original thread...even the OP here mentions it "too lazy to read the 200+ page thread" perhaps it might be an idea for each person to start their own thread so at least it can be individually searched by subject or name. I thought I would put this out there for discussion, as all these threads current now do seem to be taking on a bit of a life of their own. The OP's may get scared off by the amount of information not related to their own concerns and it will be impossible for people to find relevant information in the future or to reference things answered in previous threads. At least the original thread was a one stop shop and all the information largely in one place with satellite tutorials. So, since it has come this far and a trend if forming that has caused a lot of problems in the last year due to thread hijacking and just general confusion, I think it might make things a lot easier if people were to start their own threads on aspects that they wish to address or talk about, or particularly on their own projects. Not to put people off contributing to a question at hand, but if people are serious about their own unique projects and interests, perhaps their own thread is the way to go. In this thread for instance, later parts are dominated by a completely different project of a similar type...till I looked, I had not completely realized that the OP was not that one...and now a lot of technical questions about a particularly specific and novel hex design which is quite a different proposal from the kinds of things that most are proposing. So, my suggestion is that each person start their own thread for questions related to their project or interests so that all the information related to it can be collected in one place and the project and questions are more clear. The alternative is the maligned open discussion sustainer thread thing, which these things are starting to resemble, or a mash of multiple big sustainer threads that are unrelated to the OP or the question asked or any particular project and where the OP is often left far behind. I notice that for instance, none of us answered the question about caps I don't think asked in the original post. Anyway...I think that it might be worth discussing this before things get out of hand down the road or just impossible for anyone to utilize effectively.

I think the important thing really is that the device can change states fast enough for the frequencies at hand. So, if it is "fast" enough for the high strings and harmonics, it will surely be so for the low strings as per FF's 'solution'. Again, experimentation is probably key to prove many assumptions. It is relatively easy to make a coil that alone will drive any string as hard as is possible, but to be able to get six of them working next to each other without adverse or quirky undesirable interactions might be more tricky. Also of course there are other factors...I was able to get that previously shown single string driver design working very close to active pickups, even cheap single coils on a strat copy... Bad photo I know, pre digital...also shown is the "sustainer box" and a 4 knob compressor limiter I was using for a while to test AGC ideas. It provided me sixth something of a false hope that one might work like this, but with six of them all kinds of effects occurred even with reverse polarities, etc. They were also very sensitive to alignment, though they worked any string bending would create unusual effects. My solution was to attempt to get ever closer to the bridge till it became something like a Hex midi pickup kind of thing. For instance, this might be able to be achieved with the 'driver engine' idea, where only one driver was actually activated at a time. I suppose I mention this because in reality, factors like EMI and 'fizz' or distortion effects are important to consider. It is not enough to just throw more power at things in general or that any driver is that localized and focused. My attempts to address these things involved a lot of elaborate shielding, my hope was that perhaps I could use metal in the bridge itself as a kind of magnetic sink or something. I guess some of this thinking was in line with the Ebow having substantial shielding around it's driver and pickup. It might be worth studying the eBow for the way it works...close driver and pickup, extremely close to the driven string, resting on adjacent strings to avoid activating them...and the patent is one of the few if only proposed hex system for such a thing (though there are flaws in the idea), it seem s remarkably like the kind of thing you are seeking McSeem. But the optimization thing is tricky with so many variables...I don't think there are any 'answers' without specifications of what is essentially required. So, single string drivers can not be in excess of 10mm and even at this size, generally will be touching one another. If winding to an 8 ohm resistance, depending on your circuit, that suggests to me a lot of wire, so by necessity you will need to go thinner wire I imagine...will such a driver provide enough EMF to move the strings...well, I suspect that something could be rigged up, but the thing I would and did do is to start constructing a few things with all the necessary factors in mind to see if you can create anything that does work, then tweak these things till they are optimized and after you overcome the other problems of interaction and EMI and harmonic and resonant quirks of such novel devices. The reality is that few if anyone has done a lot of work in this area to really know, even the "theory" is only really a hypothesis till put into some practice. I believe that it is possible to some degree, though I may not fully appreciate exactly what you are trying to aim for or expecting in response, but such a system of hex pickups, individual amps, digital compensating circuitry ideas, piezo source, etc...all these things are very novel and it is hard to know what exactly is proposed and where potential major obstacles might be hiding. It is so easy to make assumptions with these things, for instance, it might be easy to assume that if you use a piezo as a source there will be no EMI problems...possibly, but I found i did and the signal needed a bit more conditioning and of course, no other magnetic coils can be anywhere near these drivers.

I'm sorry if you feel I misrepresented you there col...I think I did get the point of your post. It showed that you could calculate things and used a 55mm driver as an example, and I accept your point about inductance meters, I looked into such things a little, not sure that I personally want to go to far down that road and have yet to find one accessible or affordable to me or that would reap the benefit. Reviews I read in regards to using them with pickups, particularly cheap ones, were not at all positive. But I may well not picked up on all that you were trying to communicate, I was trying to add the physical requirements of the application into the equation. My point was that, looking ahead on the hex driver question...the physical size of each coil is very important regardless of the way the physics of the things are calculated. There may have to be a trade off. I do know from experience but it was many years ago and I don't know the specs unless I posted them early in the thread, that a small coil, about 4mm deep on a 4mm ferrite bead and a total diameter of 10mm with a tiny neo-mag below it and wound with thin wire was remarkably efficient at driving any string with an LM386 type set up. However, the full power of the amp was being used solely to drive the thing. The complications arise if you were to build 6 of these things all close together in the manner that FF has clearly done. However, as is well known, I worked by trial and error and built upon successes as well as novel ideas. So, I did not calculate out an optimized coils or anything at such an early stage, I was more concerned to create something that would work and "fit" into the physical application. Just suggesting that perhaps, the "optimum coil" that could be calculated would exceed the space required. But a small point, as my experience and intuition suggests that a major problem might well be the interaction between such close magnetic coils and cores and fields. Perhaps I am over stating the problem, it remains to be seen what people can come up with if they were to go in that direction. I think FF's 'solution' is the more obvious answer or place to pursue things, far more economically put than I seem to be capable of. I am all for the calculating of things and working on that basis, don't get me wrong, but at some point these ideas need to be put into a real world application and cover all the bases. My belief still tends to be biased towards actually putting some things into practice before getting too far down the road of assumptions. A single string driver is a fairly easy thing to do, it can even be made to fit within the space for the application...this has been shown many times...not sure if they are 'optimal', I was going to tweak these things till they were or seek more advice if the more significant problems were overcome. ... Since it may be hard to find...here is an example of an early single string driver from the hex era using the so called balanced field approach... One of these were sent to Bill Love for independent evaluation along with it's workings... Here is an example of the same drivers put into a compact array of 6 in test on what became the sustainer strat with the pickup/driver... In addition to the novel magnetic array and tiny electromagnetic elements...these things were encased in a thin alloy shell that provided a mold for an epoxy iron shielding compound that held it all together. ... The point of posting this stuff is not to big note the work I have done, but that a lot of work has been done, some problems uncovered that need to be address, how far and in what directions I took it, and that to a large extent I "failed". It is intended to be instructional. The work was not lost though, aspects of it that were discussed lead to my work with the "thin coil" or compact drivers to lower EMI spread and allow for novel applications with more conventional simple designs...such as the 'stick on' compact driver say on my telecaster or the 'piggyback' things. What I found is that the Hex things could be vastly more complicated and exhibit more quirks than something like that proposed in the Ebow patent say, might suggest...and that is essentially where people are at with these things in the DIY realm...what quite the Moog guitar that inspires these adventures in more recent times, is still something of a mystery to most but it's promoters and designers. It is an interesting thing, but there is still no technical data or first hand independent reviews that I am aware of. It may well be that people are attracted to the idea of the thing, over the 'reality'...certainly a better job at it than I could have built, but exactly what it is and how well it works is a bit of an unknown commodity as far as I can tell so far. ... As for the actual topic of this post, a bit of a view of the OP's project shows some significant deviations and poor construction techniques that at least would need to be rectified before any reasonable assessment can be made. I think that most would agree that winding wire is not the best idea for hookup wire, shielded wire can be reasonably important, and I'm not sure, but I suspect that most people know of the risks of winding with superglue and it's innate problems as a potting agent. As so much of these threads are in an effort to fix such problems or address ideas outside the known working solutions, there has in recent times been a perception that there are "problems" with this project and a bit of a myth has arisen around it. It may well be that these "myths" are trying to drive solutions to problems that are not even there in one that works acceptably. My "attitude" in more recent times then is to react to this by pointing out what should be obvious, most of these "problems" relate directly to variations and naive constructions far outside the boundaries of the basic principles and the known working designs. The "problems" then, are not in the design, or the guitar it is fitted to...but these very things. Typically we even have yet another example of "it doesn't work properly, so I will just throw more power at it solution" and then wonder why that doesn't help any. The basic project is pretty easy and forgiving, so many variations have shown to work on very many different guitar types. What we hear about in this forum generally are the aberrations that give the project a bad name and false assumptions.

Thanks for the interest... The sustainiac model C acoustic sustainer (the one that shakes the neck of the guitar physically with a transducer on the headstock) has this feature so that you could patch in effects. Some are "interesting"...and there might be some potential...perhaps even being able to generate different harmonics...Col kind of did this with his 4-mode circuit that used filters. It's tricky because you are not just processing a sound, but trying to have that signal physically more a string in some novel way. A tremolo for instance, has very little or any effect...the momentum of the string will sustain it though the loss of drive. SOme effects that change the pitch and delay, may not strike a resonant frequency that relates to the string vibration...some will ping off random harmonics like my work with flangers. FF and others like me have used compressors effectively to even out the response...AGC (automatic gain control). Auto wah or auto volumes have some appeal...especially for these blooming harmonics perhaps. Distortions are ill advised...they can provide some compression, but they tend to add a bit of noise into the systems that are detrimental. They can work despite this, none of these circuits are particularly clean run this hard...but you will never get a string to actually physically vibrate in a square wave, no matter the signal driving it. All these things can be extremely effective on the actual guitar signal and a sustainer can add new life to things like ultra long sweeps given the length of the notes. I did a demo song "siren sea" that is about somewhere that uses a pitch shifter in the middle section for a harmonized line. So, it is a real time sample at another pitch with all the harmonics and harmonic bloom of the sustainer which is kind of organic and as I recall some chorus like modulation as well...the result was a synthy organ like sound that was harmonized. There was another one around that used a choppy tremolo effect on the guitar...as the sustainer morphed from it's fundamental to it's harmonics and then yet another harmonic...that I can do on the lower pitches of my systems...it created a kind of "baba o'reily' or 'won't get fooled again' era who like sequenced synth like sound, as if each trem pulse was a different timbre and pitch related to the original. SO, there is plenty to play with there...but less os on the drive signal itself I fear. It may be possible with a complete hex system to vary the amplitude to each driver or even to get better polyphony out of the things...but there are a lot of problems as described in another recent thread...driver interaction is one major one. Part of the problem is that generally, as conceived, all this would need to be in and power at the guitar itself...a tall order. The Moog guitar, perhaps promisise some of these kinds of things with it's on board step filtering and such...but little is truly known about this thing.

I don't think so, many of the problems seem to be exactly the same...or people go way outside the specifications of known working designs. Thanks for the pics... http://en.wikipedia.org/wiki/Cyanoacrylate Cyanoacrylate = super glue This kind of stuff is dangerous and not suitable to this application regardless of what others have suggested. It has no "filling" properties necessary for 'potting' coils...PVA types of wood glue have a lot of filling qualities and are safe and water based and reversible and don't dry instantly causing voids in the winding of coils with glue. Though I have used epoxies in recent times, I am experienced in their use, but even then went through quite a few formulas to get something that had the right qualities...hardware store 5minute epoxies don't do the job too well at all and certainly not for a beginner. It is hard to tell what the actual construction of the driver is, but are the bobbin plates metal? Where is the magnet...is the magnet the core, what size is this magnet? 32 ohm drivers are far beyond the specifications I deduced, I bow to Col's descriptions there, but thinner wire as col points out may not produce the power required. You have some very dodgy wiring there...I would not be using enameled winding wire to solder circuit modules to one another. It's hard to tell what you are using for a guitar lead there, but is that even shielded? All these things seem to be indicating a lot of places to pick up a lot of noise and so effect the performance of any circuit. You really should be taking a direct wire from the bridge pickup itself before the controls. On a guitar with this many mods and I can't really tell what in it...there are going to be a lot of problems I predict. My first testing guitar for these things had cheap low powered single coil pickups (as shown in the pictorial) and phase switches on each string...but for this to work all this needs to be bypassed really. It should work in testing mode, but I'd be running a shielded lead from the bridge pickup out the back trem cavity to test these things...all leads should be reasonably short and be shielded before the circuitry, a decent gauge of plastic insulated wire should be used to the driver and other components...especially with dealing with things like 20watts of power, you ahve to have wire that can effectively carry the current to the components like the driver. There are significant problems with varying from the design to this extent, and this is where things go wrong. I have built and test these things on numerous guitars from high end custom made guitars with name brand HB's, my telecaster, no name teles and various strats...even bass guitars. There are some quirks between guitars, but all have "worked" and with little or no mods required to the basic design. If you have 9's on the guitar or very light strings, this can cause a problem...my tele would probably be ok, but generally I use 10's anyway and this is the recommendation from the commercial units for good high string activation. ... The details of the Moog guitar and even it's performance other than in promotional material is yet to be established and so very much based on assumptions on hype. We can assume such a system to some degree..certainly hex with signal probably generated from the piezo bridge and individual amplification. It does however provide for a complete all on sustainer kind of thing...so effectively no longer "hex" and one wonders why you'd do this if the hex system was "all that" and more. The muting thing is very much up to conjecture. I would not be surprised if this was a sensor on each pickup that initiates a direct current into the coils with a low threshold signal compared tot he string played, resulting in the strings being pulled to a stop by a strange electromagnet action...but this is all guess work. I could find no patent or technical data or independent reviews that detail much. I built many hex designs...I felt they were innovative enough to keep 'secret'...I took a dramatically different approach than any that I saw proposed because none seemed to address particular problems I could foresee and experienced. Mainly, that these things interact. I settled on components that I could modify that dispelled with winding and developed a novel magnetic array of balanced fields. The "coils" weren't magnetized as such, but disturbed these fields around each string pulling them in a more orbital manner. Even with such miniaturization and successful testing on individual units...a hex array still interacted. There were something of a nightmare, but I was building at least one a week of different variations for over a year before abandoning the concept. One thing that wasn't built that did show promise was something I called a "drive engine". Basically working like the cylinders of a car, in my imagination. You have an amp circuit and a sequencing switch chip take the signal and very quickly sequence through say, pairs of drivers far apart, or indeed individually. So, at no time would all six be operating at a time and string momentum would carry the "sustain" through the sequence...as I say though, very fast. It was clearly beyond my ability to successfully build and troubleshoot the inevitable clock noises and such...but there might be something in this approach, and potentially only need one small amplifier, probably smaller than that required to drive all six strings. I think FF comments are equally valid...the appropriate power and perhaps circuit bias for each string is probably the go and certainly the most obvious starting point with a true hex system. My hex systems generally assumed a mono source and intended to work towards optimizing the natural power ratios with the drivers to create an even balance and better polyphony...or so was the hope. I just developed individual miniture drivers that worked on any string to start with and intended tweaking from there. But, I failed to create a system that provided the necessary independence and I think this really is the first step to overcome. So far, I have not seen the required solutions offered up. However, FF's comments seem to be enough if all you are seeking to address is getting strings to vibrate. The other thing...and relevant to the OP's problems...once outside of the known design parameters, thigs are very much up in the air. There amy be a way of detirmining things with formulas and I am not known to be any good at that at all, but when presented with such things, I have to consider if these proposals could physically be made to the size required to even prove them. So... I'm thinking...say you wanted this value for a single string driver...this calculation seems to be for a 55mm full coil...so, for a single string you would need say a 5mm coil and given string spacing of 10mm, then there is only 2.5mm to wind on...so how deep at theses things if you have to put that kind of wire (o.27) and what effect would this have...I mean the variables and practicalities are enormous with this kind of approach. I have wound hex coils a little like this, or as FF did, very rough, and made neat little single string drivers with thin wires and small cores that worked fine (I wound the original around a 4mm ferrite bead with spectacular results, see page 2) So it can be physically possible to make the kind of thing FF did of course, and for it to "work". If they can work as a true hex system is another matter I suspect. My feeling was some of the big picture problems meant that a far more innovative approach was necessary...things like the magnetic array thing, the drive engine and countless other flights of fancy. The ironic thing is that many of these things were based on "fears" about the effectiveness of a simple design, many assumptions that I sense are being repeated before me in this subject and that I once had, a drive to make something "better" and "novel" and, an ability that I ahd developed to make these hex systems without winding coils and significantly smaller and with less EMI than anything else I had conceived of. They were even smaller than the smallest simple designs I had created till the newer wafer coils...but I don't know that these would work without the core of the host pickup. So...unfortunately, I couldn't guess as to what is "optimal"...it is still not entirely sure what you are trying to do...but I would start by using FF's assertion that if it work on the high e notes, it will work on all, and altering the power could provide "balance". Regardless of anything you might do, there will for sure required a whole lot of experimentation...as I say, I built well over 50 drivers in my "hex era" on these things. There should be plenty of pics about...I could refind them from photobucket, but there are a lot of them.

Hi Ansil...I know what you mean...but I still recall some interesting discussions early on about some stompbox like alteratives to infinite sustain, and while I tried and tried but couldn't get the effect that I was seeking with the infamous sustainer mod tutorial (I just got screaming feedback) it was the search that led me to PG when looking into these things...so, perhaps you contributed more than you think! ... As I imagine it should No, rarely do the harmonics sound as the fundamental on any of these systems and I wouldn't expect them too. In playing the things I try and think a bit like a trumpet player say that only has three valves and the ability to "blow" different harmonics to get the various pitches and registers. Still, it is a beautiful effect to have these other notes bloom out of the original...and generally they "work" as these harmonics are a part of the original sound of the vibrating string. ... This sine wave philosophy has been very contentious in the last year, so I realize I am getting into dangerous waters to even comment. It was one of the last straws that broke the back of the main thread, spawning many of these related conversations that would have continued there...again, IMHO. However, it is a matter of "ideals" and "preferences" if this is the effect that is sought in my opinion. The "sustainer" is simply another means to sound the instrument, like a pick or a bow on a violin. It has never been my goal to have a device that turns into a sine wave and made my opinion clear that it is the bits of the sound that are not a "pure sound wave" that give it character and so called "tone". One could look at the vibrating string as a collection of vibrating modes...fundamental and harmonics, and these exist even if swamped by a harmonic and can easily be revealed by dampening at nodal or anti-nodal points along the length of the string, well after sounded...proving that these other modes of vibration still exist within a give note long after the initial strike of the string. So, to have a sustainer that continues to excite these harmonic nodes, or even bloom them in preference to the fundamental vibration, is a beautiful thing and the subject of this thread no less. There seems to be some confusion, perhaps all on my side, that you are talking about harmonics that sound the same note as the fundamental, and that is what you felt incredulous about being possible in your theory. As harmonics can be generated consistently with known sustainer systems, several on the market, it is obvious to anyone that it is indeed possible to make harmonics and for these to "bloom" out of the original fundamental. Octave or similar harmonics may indeed be unlikely with such a technology as is currently envisaged, but then if that is what you meant it might be an idea to clearly state that. But as I say, i am a little confused... "the" corresponding harmonic? Do you mean the octave or note of the original pitch. It can happen, but is rare, generally it is a higher order harmonic...my low "E" string will sound the note B and octave+5 higher than the original...the blooming effect is that for a while, both notes are apparent as the harmonic tone gradually takes over. Getting octaves only to sound would be difficult. I did try things like bridging diodes and active half wave rectifiers and such, didn't go so far as an actual pitch shifter as I didn't have one at the time of these toyings, but with little success as far as getting specific harmonics to sound...but there may be something in that kind of approach. As always, at test rig to prove the theory or make it work is necessary if that is what is aimed for...talking about it wont really help a great deal till a concept is put into some kind of practical application or test...IMHO.

I assume by "knots" you mean the nodes and anti nodes of the string. The theory that "you will inevitably have certain harmonics at certain positions that are impossible to sustain" does not mean there are dead spots...simply that different harmonics are sustained or driven. You won't get all 2nd order harmonics but this will change in a somewhat predictable nature across the board. In practice, most drivers are big enough to span the 'point" at which vibrations cross and can drive the strings appropriately regardless. If you consider a guitars pickup, these do not prohibit harmonics being heard or dead spots because they are far bigger than these so called "knots". Not sure the extent of "digital processing" that are a must, but the patents and current devices use various ways of effecting phase compensation for their drivers...FR is perhaps the easiest to understand from memory and an old patent now. However, the kind of drivers and designs typically work very well without any phase shifting as they were intended to do. In my work, it was the late Lovecraft (bill love) on this forum that encouraged me to concentrate efforts on the driver to avoid the necessity of phase compensation. I don't believe any of the DIY sustainers (except perhaps dizzy's from another forum) have used phase compensation. I did quite a bit of work on so called "acoustic sustainers" like the sustainiac model C and many variations. The transducer is magnetic and sits on the neck and requires a fair amount of power to shake the guitar neck. It too can suffer from different resonances in the instrument and the system. Piezo ideas have thus far failed on my side and seem very unlikely to work. Also, driving on a node is perhaps not the best idea...this is kind of a fundamental still point...two certain nodes are the bridge and the nut. It would also appear to be some EMI like noise that can get through piezo systems with these types of devices, I am not entirely sure what is going on there. There are also a lot of lagging phase problems with anything mechanical...say my experiments shaking a strats fulcrum trem...there are significant momentum forces to overcome with such mechanical systems. Plus, they tend to make a racket and are not as efficient as applying the forces directly to the strings themselves. ... A few interesting harmonic effects that any sustainer can do and is kind of unique If in a strong normal mode and you ping a harmonic (say 12 frets above the fretted note) it will morph back to the lower fundamental with the drive...so a reverse harmonic of sorts. If the intensity is adjusted way down, below infinite sustain, as a note fades out naturally, the tail end will sound as a harmonic as it fades...great for adding a unique if subtle detail. If you play a note, switch to harmonic mode while sustaining, it will rise to a harmonic, if you switch back to harmonic mode, often you will get still another higher harmonic, eventually it will return to the fundamental...a bit like a sustainer version of pinch picking harmonics along the length of a string. A chord can have added harmonic extensions from harmonic drive on the predominate lower strings...a harmonic on my guitar on the lower strings tends to sound higher than the notes on the high e in the same chord. There are some really weird "psycho-acoustic" kinds of effects you can get. I was playing with some of these last night...using a delay on the guitar and a tremolo arm, you can generate the appearance of two harmonics both rising and falling while 'pitch bending' in this way...tricky thing to do, but very cool. ... An effect of the driving of a string with a sustainer allows for the shaping of the envelope. It is possible to pick lightly or just fret an not and it be driven "from nothing", increase in drive and so volume, then can be cut short with muting...the result there can simulate in that instance a 'backwards guitar". There are lots of other effects possible with these devices, the "problems" often exist in the ability of the player to treat it almost as another instrument, damping is incredibly important...it is possible with careful damping to lower the envelope then allow it to return for instance. ... I'm sorry to sound negative about the digital stuff, but we have heard these ambitions before and have led to nothing, at least so far. Same with many of these 'issues'. FF uses a compressor on the signal to effect an AGC, but that's pretty much the standard way of producing AGC. The certainly is a lot that can be done with digital stuff with this project, but it would need to be tuned very carefully and probably specifically for any system and guitar. The processing itself takes time and any digital processing must have to compensate for it's own lag in responding compared to the direct analogue approach. It could work, but it will be tricky and the benefits are a little obscure to me in a comparative approach. The only way to really convince people of these ideas is to put them in practice. However, last time, over a year it morphed from a hex system to a mono/digital thing (using pics) to a basic amp and design very typical of what has been working for years...without any acknowledgment or disclosure. So...I am wary of the "theoretical" discussions where the practical work is not done. Also, still not absolutely sure that I appreciate what is being searched for that a conventional simple sustainer can do. I can see where Col is going to a large extent and am confident that something will come of it. Still...I'd love to be proved corrected. So far, in all the years and people coming and going, it has remarkably come back to very similar simple ideas that have persisted. In my own work at least...and I have tried everything from hex designs to piezos to "acoustic" versions, mid drivers, bridge drivers, mini ebows...the more conventional designs seem to have come out consistently more effective on many levels. ... Oh...I just saw your last post Al... Pitch shifting was something I was considering...but not sure that this is worht the effort...it can easily produce and with more control to use things like the whammy pedal on the guitar itself...a different kind of effect, but certainly works. Not entirely sure, but I think you would get that "reverse harmonic" effect...hard to tell without trying...but a lot of electronics and power hungry to put inside a guitar don't you think? Another thing to consider is an auto-volume pedal like a boss "slow gear" to bring the drive in later in the form of the note...this would produce a "blooming" effect. I'm not entirely sure though...it is this morphing to a harmonic that you are interested in? This will occur naturally if you lower the drive intensity a bit so that it takes a little more time for the sustainer to work it's 'magic' on the picked note. You can also use the drive control much as you would a volume swell to bring in the sustain and the harmonic effect which can be cool. It's still a lot to be thinking of while trying to play the darn thing though. ... I may have mentioned it before, and before I hit the road for a while...I ahve been considering making a taping instrument that is driven by a sustainer or even hex (or however many strings required) system. The idea is to damp it at the nut end like a 'stick' and use the sustainer to generate notes and swells just by tapping notes with both hands upon the strings. It sounds like a really cool potential for the technology...but potentially very difficult to play I imagine! I kind of envisage it like a lap steel or even pedal steel kind of thing, so potentially you could use your feet for controls and have less reservations about it being remote powered or overly compact in circuitry. Just a bit of imagining...

Phase shifting was something I worried about very early on and a lot of emphasis is put into the patents concerning this aspect. The use of filters to select for tiny delays is commonly used, the floyd rose sustainer patent has some easier to understand ideas on how they auto-selected filters with frequency. I don't think such a delay chip is the way to go, we are looking at very tiny delays given the speeds a which strings vibrate...capacitors provide a far more effective way to go I might suggest, but these concerns seem to be the things that some are concerned about with the idea of digital processing. My perspective was to create a driver design that was "fast enough" to work on the range of the guitar to avoid these phase concerns, rather than having a driver that needs compensation to get a good response over the range of the guitar. I believe that various simple designs have achieved that. It would seem that the driver designs of commercial units and some other proposals require such compensation circuits. One problem is that the the drivers inductance will change with frequency and the guitar is not a monophonic instrument. So, if you play a chord, how will such compensation circuits handle such a signal? Perhaps the answer is hex designs, six amps and compensating circuits, etc...but really, this level of complexity...what is the pay off when a simple solution will work? So, one way to consider the reversing of the driver leads. One might on the surface think that by reversing the process of string driving you would create an anti sustainer...and it is possible in special circumstances to observe such an effect. However, I look at it as stopping the main fundamental frequency and so leaving the next strongest harmonic in the series (very often the fifth above) to be driven...creating the harmonic effect. A bit like stopping the string at a modal point, leaving behind the harmonic behind it. ... The desire for "harmonic blooming" can easily be created as well as several novel harmonic effects with the conventional sustainer and the reversing of the driver leads. Having too much control that is hit and miss in performance would seem to be asking for problems...it needs to have some automation I'd suggest to be useful. It needs to be understood that while the harmonics are predictable, they are not usually octaves. So, in playing, the note that sounds or blooms out of the initial note will not be the same pitch. However, it tends to sound musical since it is a part of the original notes harmonics. There is also the fact that in western music we use a tempered scale...the harmonic note created will be from the natural harmonic series. So, there can be some thinking about the notes fretted and the notes produced when playing or composing for the thing. ... My circuits are typically tuned to create an effect I like that is essentially a "compromise" in many ways. I like that organic bloom thing, especially in the lower range and am happy for these bass notes to evolve into others and keep things simple and responsive all over the guitar. I know Col for instance was very concerned that in the fundamental mode that low notes should ring as sounded. Adding more switches to alter caps could easilly achieve this, having a complex circuitry of frequency analysis that switches in delaying caps is a way that FR describes. Others may take in digital means. However, everything in the chain, especially things like digital processing, causes delays and phase shifts....even the driver itself...so, how much compensation are you going to do, who has the knowledge and equipment to truly calculate this out in the real world? What is the pay off for such complexities compared to simple solutions? ... There are things to explore and there may well be many things that surprise me, but given that the expertise in circuit design has failed to even address the standard circuit issue, even as they complain about the F/R solution offered up, or the mods to my specs suggested...seems to indicate that we are not there yet. My experiments with things like flangers and delays in the early days were to explore these areas and i didn't find them that great. I have an old tycobrahe pedal flanger that can do static auto and pedal sweeps for instance...I got bird like chirps as the pitch shifting struck off various natural harmonics...I imagine this kind of thing would be the effect and not entirely useful. My suggestion to anyone wishing to explore these things is to make a simple known working design to a standard that works and see if that fits the bill, or where it needs improving for your musical preferences. To me, time and again people seem to be reaching for solutions to problems that don't seem to be there, or going straight into complexities beyond their abilities (and mine) in anticipation of solving problems not there, or for marginal or unspecified gains. There are limits to this stuff as well...it might be nice to imagine holding a chord and all the notes to come out evenly as an octave above...but I suspect such things are close to pipe dreams and similar or more controllable effects can be had with digital modeling with current technology on any guitar. You might thing adding more controls that are performance sensitive is a good idea...but you may need another player to operate these controls while you attempt to actually make music...no? ... So delays...I'd be looking at caps...even with a drastic change from say 220uF to 100uF on the output cap only effects harmonics on the very low end of the guitar. On bass guitars, I tried running caps at 470UF and higher and still getting harmonics. I don't think it is a predictable as you might imagine or as global to effect all the strings...the instrument could become so sensitive to such adjustments as to loose the predictability that is necessary, though it could produce a range of "effects". Anyway...just a few thoughts...but you may well be surprised about how well simple approaches can work, and how adding any complexity can grow exponentially, and easily to the point of not working effectively at all. It's a very fine balancing act as I and many other have found out.

Hey Al Well, the question needs to be asked, and tested. There might be a bit of an effect, but unlikely enough...perhaps with hex designs a little more...but then there are other problems. Thanks for a great reply though...obviously I used the same thoughts when I did things like this. I confess that since moving a year ago, I have done no further construction on these things, though having moved again, it may well be possibly that I will explore a few areas and still have some projects to complete. However, far more than was ever posted by me, believe it or not, was tried. I have literally made hundreds of variations on all kinds of devices over the years...some I didn't report on because in retrospect they were a bit stupid, trying showed me why...so it goes. It can be frustrating when I see some dogmatically suggest things that I have experienced to be a bit of a dead alley without trying it and so revealing the things I have missed...or demonstrating where I went wrong, which of course would be even better! ... AGC can really help...it's a tricky thing, it could be come a little too sanitized in overall response for my tastes, it really depends on the effect you are after, certainly the commercial systems are a bit more evolved and go in this direction...there is a lot more that can be done. Col really got a handle on this a showed a circuit with several modes and a lot of AGC, and it got something of the effect he was after, but it lacked some of the dynamic range that I seek in my devices. These things are a little a matter of taste. It will be interesting to see how a bi-lateral driver with separately atuned coils for the string sets might further address these things. ... Early on i had a fair hope in processing the signal that drives the strings in the hope of vibrating the strings in novel ways. Some were interesting, some had little effect and some seemed to have little effect at all. Far more effective to process the actual guitar than the trouble it was worth. A flanger can have an interesting effect by sweeping through harmonics and making bird chirping like effects...not sure how musically useful these things are. However, a radical tone control will have fairly dramatic effects...such as an equalizer. As I mentioned above and before, I tweak my circuits with adjusting the output cap so they have less of a bass response than you might want with a speaker...this tones down the lower strings a bit and ensures a powerful high string response...so in effect, evening the response of all the strings. So, there are some myths about string response though they are not as even as if this were combined with some good AGC. If you play with distortion or a compressor on the guitar...this itself produces a pretty good evening out of things, so there are solutions even with a highly dynamic system like mine, as long as all strings are being driven well. A side effect though is that notes below C on the g string, 5th fret blom to harmonics, generally a 5th above in the fundumental mode. I quite like this effect, I can moderate it a bit by turning down the intensity...but it is a by product of the circuit tweaking. I could have added a switch I suppose to switch in different output caps. An alternative might be some kind of active tone control as you suggest. The effect of using such an equalizer would be to accentuate different harmonics in a strings vibrations and therefore create different harmonic effects. However, if adjusted to produce a nice even bass fundamental, you might lose high string response. But then, does this even matter if this is the kind of effects you are after. A wha like device has some really interesting effects...to the drive circuit, or simply on the guitar itself with a sustainer. The "Sustainiac" equiped guitar I have played, had such a control on it and was very effective...it was an older model and I am not sure they offer this anymore. But as far as string response evening, radical tone shaping may not be the way to go...for an effect, yes. Remember that behind the lowest fundamental frequency that a string vibrates are all these harmonics and driving different frequencies generally brings these out. What you might fix in the higher strings, you may lose in the lower. This is exactly the kind of compromise I am happy to live with in most of my designs...I actually like the effect, and the harmonic function creates yet another harmonic sound to those in the 'normal' mode. ... For me the "sustainer" is not so much about the ability to sustain a string for as long as you want. What interests me is that it is a way to excite a string....just like picking it. It is a way to play with the envelope of sounds and to manipulate a sound while being sounded and to produce harmonic effects that are organic. It is also an extremely powerful kind of sound and a really different 'feel' to the instrument. However, it does require learning to play the thing, especially a system with a lot of dynamic range like the kind I favour. I was using it a lot last night in fact...it really can be a cool device when you are in the mood...but the guitar itself is pretty cool, so you wouldn't want to build anything that might take away from that in the pursuit of sustain. ... So...yes, a bit of an equalizer can be an interesting effect, but how much you are going to want to put into a guitar and power and all the rest of the problems associated with playing such a thing...well, that's up to the builder. My goals were always to try and make the things effective and as simple an small as I could, to leave the host guitar in tact as far as possible...then work out how to use it in an effective musical sense...still working on that last one...adding a graphic equalizer into the guitar seems to go against that for me. But, it will only work well, with a decent sustaining system...it won't fix problems inherent in the designs or construction and there are limits to what such things can do.

It is a good option...the thing with a lot of these LM386 amps, and there is a lot of them about, they can move a fair amount of air if you hook them up to a proper speaker...use a 3" computer speaker and it ain't going to sound too good. This also shows the limitations..."blues crunch" is not necessarily the signal that you want to drive the strings, but potentially it might be cleaner than the F/R. I think the only way to get really clean headroom is to use remote power...the LM386 can run fairly clean with adequate power or tamed down...on the other hand...Col's proposal to increase efficiency in the driver design might make getting a cleaner signal and less problems easier as well for the same or less power. Unlike with speakers, you don't hear a driver, so it is difficult to tell what the signal coming out truly is other than by the effects it has. My feeling has always been that a little amp like the LM386 is perfectly adequate enough power to have the desired effect, as long as there is enough efficiency in the driver design. If there isn't, adding more power may often just be adding more to the problems that are in the system, not the circuit. Hence, most of my attention remains on the driver side of the equation and resist the idea that the "magic" is in the circuitry with this project. But, why not use a variation on this idea, similar mash ups tend to be what most have proposed and this is certainly better than some I have seen lately...tillman for instance with a different amp chip...it really is much of a muchness. I'd probably prefer this kind of thing to a F/R myself...no bias trimmer for a start, easier tranny to locate over here at least, still potentially very compact. But, there are far more knowledgeable people than me on circuit design, I'm just disappointed that none have come forward with an equally good standard amp proposal to this one or the F/R after all these years for a small battery powered amp.