onelastgoodbye

yes I have, but haven't been able to test it yet as my guitar is currently 'under construction'. I have aquired a bunch of 2 x 2 neodymium magnets as well, so i can get cracking at a side driver. Still have to figure how the configuration of the magnets will be as they have pretty weird magnetic behaviour, and they're probably too strong right under the strings; maybe 2 per string with N-N facing eachother and the string in the middle?

Whwn the driver is engaged, the pickup that acts as a sensor has to be as far away from the driver as posssible to avoid interference and massive feedback ( squeeeeel). When the driver is disengaged, it doesn't matter and you can still use any pickup you want. so yes, on that Les Paul the neck pickup is disabled when the driver is in use. The reason why the driver is usually placed close to the neck is because it's easier to excite the strings in that position (the strings have more 'play'). Ideally, you'd put the driver in the twelfth fret position on the neck... Now, the dual coil driver (the humbucking driver) can be placed fairly close to the sensing pickup (so you could use it in the mid position with the bridge pickup as a sensor, or in the neck position with the middle pickup as a sensor); because it's a lot more resistant to feedback and EMI. However, you still get a slight distortion in the signal, which is audible, especially on clean sounds. think of it as a clean sound with a fuzz box added. If you only use distorted sounds, it might not bother you that much. the theory is that the driver and pickup are effectively acting as a transformer, up until now we still haven`t been able to adress that issue. your theory about the tall coils....mmm...maybe. I (think) you'd might find the opposite to be true, but my knowledge of how a magnet's shape affects it's field lines is too limited to give a definite answer. One thing I'd like to add though is that the coil in itself does not have a real magnetic field. it's the magnet and the core that create and shape the magnetic field. The coil creates an electromagnetic field which 'piggybacks' onto the magnetic field of the magnet. Again, how the shape of the coil, magnet, etc...affects the final electromagnetic field is very much open to discussion. We've always had best results with fairly flat coils. I do believe the best way to avoid emi is to use 'no more electromagnetic field than needed' by using a physically small magnetic field and positioning the coils as close to the strings as possible. Positioning the coils close to the strings is easier when you have flat coils (they can lay on top of the pickups). As for the small magnetic field, either you use tiny neodymiums as the core of the driver, or you use the big ceramic pickup magnet that's already below your pickup coil (as explained in psw's sustainer driver pictorial). because it's below the pickup (2-3 cm from the strings), it's magnetic strength in the area of the strings is relatively small. on the coil wire diameter; I have built drivers with 0.3 mm wire and although it does work, it's not nearly as efficient as the 0.2 mm wire, plus the coil gets substantially larger. You should really use 0.2 or 0.25 mm. Required length for an 8 ohm driver is only about 12 m for the 0.2 mm wire.

Just got these in the mail...found them in Austria through a colleague from work. I'll have a go at zfrittz's circuit over the weekend. Maybe I'll have time to do some more visualisations as well. Busy, busy, busy . Tim

starts from here http://projectguitar.ibforums.com/index.ph...st&p=167113. All my images are also in this folder. You can see a prototype box in the subfolder proto_box.

Something for the next 100 pages; I was thinking about a patch-through box that simply plugs into the guitar jack, with all the circuitry, battery, basic controls and a jack to plug the guitar chord in. I *think* that a dual driver could work in the mid position without any fancy switching config, just switch to the bridge pickup and turn on the sustainer..I have a one-pickup guitar though, so maybe I'm being too optimistic there...maybe a 6-way toggle switch instead of a 5-way, with option 6 being the sustainer. Anyone have any idea on a simple way to incorporate these? On the circuitry front, I've got dibs on 2 tda7284's so hopefully I can get cracking on that ACG Driver-wise I've found a supplier of 2x2x2 mm neodymiums; would make for the perfect Creditcard Driver™

love the electronics cavity !

not really when using the driver (unless it's at full power); this is a cheap plyood guitar with baaaad action though, so whenever I'm normally strumming or picking the strings hit all over the place. I tend to think of it as fret slapping ahum...'technique' that I have incorporated into my... 'style' why is it I get all warm and fuzzy inside when a new opamp pops up? that one looks pretty promising...with all the new ideas and to do's popping up we'll have another few pages ahead of us. I have another box concept brewing to address the whole battery/implementation thing as well...this thread needs some more fancy renders .

I'm using full power as well, volume is only halfway though. Was playing the sustainer this weekend, it's so friggin cool! what I love most about it, is the ferocity it has. There's surprisingly much power for such a little thing,keeping in mind it has loose cores and the coils could be potted better (the epoxy hasn't fully hardened). One thing I've noticed is that there's no real harmonic or fundamental mode...everything eventually shifts into harmonics, only in fundamental mode (or in what I suppose is fundamental mode) it just takes a bit longer. Everything below the twelfth fret shows more resilience to shiffting,too. The fact the driver sort of has a mind of it's own might seem a disadvantage, but I find it really adds to the natural feel of it, as this behavior is what I would expect from natural sustain or feedback. I got the same phenomenon on my single coil drivers as well, so it could just be that my setup lends itself to favoring harmonics. the unpredictability factor also tends to make you improvise more, which is a big plus imo. Now if I ever get round to that acg circuit...and the internal magnets...and epoxy shielding..

complete driver the (lousy) pics of my rail driver, as promised. The lighting makes it look as if there are loose windings, but actually looks very clean in reality. this should give you a better idea look on the far right @Donut Man I've been using the little gem circuit with my emg and it sustains quite happily...the little gem is basically of the ruby without a preamp section; emg's have an internal preamp section, so 'technically' you don't need that, just a poweramp. @PSW good to have you back, I'll shoot you a mail one of these days. Tim

There's probably a considerable loss of efficiency for just that reason, but I'm not gonna glue the cores down yet, as having (re)movable cores allows me to experiment with a few things: By sliding the (laminated iron) cores up and down the coils, I've found that the distance of the cores to the strings has far greater effect on it's efficiency than the distance of the coils to the strings. If the cores are further away from the strings, there's a definite loss in power. If the cores stay in the same position, but the coils are moved back, there's little to no difference. Some furter testing is needed to verify how the proximity of the magnet to the strings comes into play." Thanks for finding that post for me, Col. I didn't realize I haven't posted pics of my rail driver. Expect some tonight as I'm at work right now. Bassicaly it's the dual coil version of my realy thin driver. works really well with the little gem, it would make a killing with an acg circuit. I have been trying to find a tda7824, but no luck...looks like I,ll go for the Col-pressor after all; but it might take a few weeks. I have done some experimenting to see how the proximity of the magnet comes into play; the thing is the magnet (and it's field) is so big in relation to the size of the coil, there's no real discernable performance difference between putting it, say 1mm or 10mm from the strings. It's a ceramic bar magnet from a single coil. If anything, the magnet is way too big, and I suppose there's some efficiency to be gained (and emi reduction) by using less powerful, tiny internal magnets (though I'm not sure if rare earth magnets that close to the string are a good idea, strenght-wise). You probably only need a small saturated field, anything more is overkill. That explains why it doesn't help much if I stick more magnets underneath the driver, as the field is already saturated.

the dual rail driver does work in the mid position, you know... it's a little hot and on the verge of feedback, but nowhere near as 'screamy' as what I experienced with my single coil drivers. I'm wondering how the magnet configuration is on those lace pickups....might interfere with the 'classic' approach of putting a driver coil on top and using the pickup's magnet. Tim

Yep, is the way to go IMHO, only trouble is that with this kinda set-up it's impossible to have angle headstock. Why not? you can always 'pivot' around the slanted line of the nut. Sure, it's not the standard way of doing things as the headstock wil be angled in 2 directions when looking from above, but an 8-string isn't too standard anyway. On the q-tuners, the hardest part of building these yourself would be the floating coils. I have made a few of these for a sustainer driver (look for jiggamathingie and core-less coils in the sustainer thread). It is really tricky to remove the temporary core without damaging the inner windings of the coil. And this was with 0,2 mm wire, which is a lot thicker than what you would use for a pickup. One possible way around this is using a perspex core with the magnet mounted on/inside it, then wind the coil applying epoxy/polyester/polyurethane while winding (you'll temporary 'bobbins' to block off the top and bottom as well),let cure, remove the bobbins, then cast the epoxy casing around it. The cheapest way to get single string bridges is probably to get some graphtech wilkinson saddles and make a base for it, like blackmachine does.

I was under the impression that hex piezo systems like the graphtech ghost system and rpland pickup put out six midi signals, not analog ones, which would make the implementation much harder?

OK...this thread has gotten so big I can just reference to other pages @ Radiotrib Click here and here for the humbucking version of your idea. It's a cool concept and definately has a lot of potential. You're right about the flux thing. sadly enough, the coils are in the least favorable orientation for an efficient manipulation of the fixed magnetic field...perpendicular to it. Basically the shape of the permanent magnetic field is very good, but the coils (which are supposed to induce variations in this field via their own electromagnetic field) don't have much "pull" on it. Well, something like that. Please prove us all wrong..this thread started out as 'ideas for a sustaining device' so anything goes, really. There's a good free 2d field modeling tool called FEMM which has been used a lot quite a bit throughout the thread. i have ANSYS Multiphysics (3d analysis tool) as well, but it's waaay too difficult for me. @ Samuel McBrian- Brian So you want to manually switch each individual driver on and off while playing depending on which string you are? What I meant with the six amps is that you'd need those for OPTIMAL performance...just six separate coils won't make a big difference versus one big coil, because your feeding them with the same signal. For optimal efficiency you'd want each driver to be 'tuned' for it's corresponding string. You could do this by using less or more wire, different gauge, different magnet, etc.. for even better performance you want to feed each driver with it's own 'tuned' signal, which means you need six dedicated amps...then ofcourse you need to feed those with six separate input signals. You can't just use a simple crossover circuit to split those signals from the pickup signal, as a lot of the notes (thus frequencies) on the six strings overlap. So it would be easier to use six separate sensors. Don't let this hold you back though, I would love to see a return of the hexaphonic driver! greetz, Tim

@ Samuel McBrian-Brian Hello and welcome...Col posted a link to an online coil calculator some time ago, can't find the link right now....I measure the length of wire needed before I start winding and a 4 ohm coil (half of a humbucking driver) comes to precisely 6 m with 0.2 mm wire 32 (awg). It seems the winding of the coil adds some resistance to the ohmage of the wire itself (because the overlapping influence eachother I guess). So don't use those calculations as an absolute measurement. The resistance isn't all THAT important anyway, I doubt you'll "notice much difference between say, 7.5 and 8 ohms. What really matters as far as driver efficiency is concerned, is how well the coil is potted, and the wire gauge. So far it's always been either 0.2 or 0.25 mm wire, but you'll find the 0.2 makes for a much smaller coil than the 0.25. About the six coils, only psw has experimented with that and it was quite tricky to control EMI, let alone build those tiny things. You,d also need six separate amps to take full advantage of them, which means lots more power drain and emi to control. So the hex drivers are 'on hold' basically. @ Radiotrib your idea about the coils on their side is similar to what fernandes originally used in ther sustainer guitars. The patent is on ... page 100-ish. We call 'em side drivers here. I want to build one myself if i find the time. Basically, they should offer superior EMI resistance because of the way the magnets are positioned, but it has been stated that efficiency might be poor as the coils are on their side. Check out q-tuner for some cool pickups that use the same idea. Nederlands bedrijf trouwens . @ Zfrittz Could you post some pics of your new super-thin driver? I'm interested in how you built it. Any test reports?

they need to face the same way. Doesn't matter which side it is, but they either have to be all N up or all S up. Otherwise their electromagnetic fields cancel out (err...I think), which is mabe why you only get good response on the ead strings. Also, what did you use for potting?

They will all work, but it seems some of these are purely power-amp modules, you'll need a preamp module for best results.A preamp is used to ''condition'' the signal from the pickup, so it can drive the poweramp more efficiently. A preamp is usually only a few capacitors and resistors though, so you can easily add them if necessary ( they could already be there, but I'm not much of an electronics guru, so you might want to wait for others to chime in). The mini tube amp circuit is nice, but a little too much power than needed. the driver needs about 0.5 watts/ 1 watt max. You won't damage anything by using (a little) more power, but the batteries will probably drain faster. Thruth David The kinman pickups have been mentioned before, they are indeed very interesting designs. The sustainer driver *could *might *maybe *possibly* be used to cancel hum from a single coil, but I imagine it won't be that easy. Surely Kinman themselves have invested a few years in perfecting the design...maybe we should make a ''to do'' list . If you want to go for the kinman pickups, by all means do so, it should be possible to mount a thin driver on top. My latest driver is only 2mm thick and would be able to just slide over the pole pieces, so that would solve your pickup height worries, and it looks pretty neat too. Are you in Spain? I might be able to send you one; or I could write up some detailed instructions for Zfrittz to build one. Let me know. Using the piezos to drive the sustainer would actually solve some of the problems with switching and emi we're experiencing, as they are non-magnetic and thus can't be influenced by the driver's magnetic field; so you might want to consider that. oh, and the build thread is here http://projectguitar.ibforums.com/index.php?showtopic=16984 greetz, Tim

Ok you probably know this already, but it might be of use for someone else reading this With CAD systems, there's two main types of modeling: 'surface modeling' and 'solid modeling'. Surface modeling is where you design a shape by defining it's outer surfaces by curves; solid modeling is were you basically start from a solid block and add or take away pieces. Most programs make a distinction between these two techniques, or only use one of them (well). It seems you're trying to do this with 'solid' modeling, wich won't work. Any freeform or surface that is bent in 2 directions has to be made with a 'surface modeling' technique, like railsweep, network surface, etc.. I'm not really familiar with solidworks, but I believe it also does surface modeling. Surface modeling can be a bit tricky (cnc is the easy part) as you have to define the curves that make up the surface and then make sure surfaces match up. This is a model of a js I did, mainly with railsweep. If you'd like, I can draw the curves on. doing a LP would be totally different though. Tim

I have too agree with you here. There's lots of dead ends and misleading stuff in here, not to mention all the circle-thinking and repetitive ideas. Let's stick to some idiot-proof and uniform tutorials for now. Maybe a small knowledge database with links to the patents and external stuff so people can get brainstorming if they feel like it; but this main thread is like a big brainstorm in itself, so it'd be better to summarize it's (succesful) results rather than the whole thread. Sure things like the box were nice and all, but if it's of no use in the end, it's of no use right? It would be easier to take the topic to it's own site as there'd be more options for filling in the content, but there's this *special link* between PG and the sustainer thread, it would seem a bit wrong to take it off-site after all this time. Plus you'd have a hard time generating the same amount of traffic PG does with your own site. Tim

I can do an in-depth tutorial of coil winding (bobbin/no bobbin/cor/no core/blocked-up sides,...etc). It's what seems to scare people the most, so I guess it would come in handy. Maybe we could make a section with all the different (succesfull) driver designs to date, being : the single thin driver the dual rail the bilateral driver the dual rail-bilateral driver? the side driver? the hex designs? ansils piezo-driver? with a picture of each, and then a short description with the pro's and cons (which I'm guessing will mostly be "produce-ability" versus efficiency and emi rejection) We could do the same for the electronic circuits: the little gem the ruby the fetzer-ruby the champ? col's circuit zfrittz's circuit It's probably a good idea to have a short intro section as to what a driver is and how it works...the core, the coil, the magnet, and how the y affect each other. Plus maybe a concise report of the major hurdles to overcome in driver design...emi, crosstalk between pickup and driver, switching... I'd like too see these sections pinned and closed, so they don't get cluttered with questions and answers..the questions could be asked in their own, proper thread. oh, and pete should be a mod so he can update when needed btw my little driver rocks...cool to see al that power from such a small tidbit. It holds up pretty well in the mid-ish position too. I still need to build an acg-circuit, but all the stores are closed this time of year so I can't get the parts... 2 cents from a page 32 vet Tim

Oh man, that's bad news. He was such a great asset to the sustainer project and the electronics forum. A real wise man too, with a wonderful feel for the English language. I loved how he could make his point come across with just a few words. A true moderator. Farewell, friend Tim

See I told you guys it'd be finished by page 150 I've finally been able to test my super-thin rail driver with a new lm386 (fried the previous one) and it works a treat. Good performance on all notes, and the humbucking feature really makes it a lot more controllable than my previous single coil drivers. I'm using the little gem amp, fed by the (internally preamped) signal from an emg. The 386 is at max gain (200) with the volume halfway. Will try and see how far I can get that gain down in the next days or so. The fuzz is still clearly there, I'm now pretty sure that it's the signal from the little gem bleeding through. Bear in mind this is an active pickup and I'm not using a separate preamp, so there's probably lots of issues with loading and batteries etc. Plus you can hear the driver generating the exact same sound (effectively working as a speaker) when I turn it's volume up. My cores just slide into the coils and are thus not permanently fixed (yet), so the coils are actually moving up and down under influence of the EMF. There's probably a considerable loss of efficiency for just that reason, but I'm not gonna glue the cores down yet, as having (re)movable cores allows me to experiment with a few things: By sliding the (laminated iron) cores up and down the coils, I've found that the distance of the cores to the strings has far greater effect on it's efficiency than the distance of the coils to the strings. If the cores are further away from the strings, there's a definite loss in power. If the cores stay in the same position, but the coils are moved back, there's little to no difference. Some furter testing is needed to verify how the proximity of the magnet to the strings comes into play. Now this is interesting... I can use the driver in the mid position AND it seems to work a lot better here, much much stronger signal. At least as long as there's a note going. When the strings are muted, the driver is much more prone to squaling. Psw referred to this back in hex driver-time, I think, but it's as if the driver signal is piggy-backing on the microphonic feedback between the driver and the pickup, and so, beefs up the signal. Maybe something that can be used? I need to get rid of the little gem coming through first, though, so I'm gonna build col's circuit once I get the parts saturday-ish (grrr...electronics stores) and see what gives. Say Col, seems you've made a bobbinless driver too, how'd that go? Tim (not posting but always lurking)

A quickie from me ... Considering the install space issue, I don't recall we ever seriously considered a strapmount box for the circuit and battery? More like a feedthrough box were you'd take the signal from the guitar jack, run it to the box with a short lead, split the signal in the box, then run your regular chord out from the box to the amp. The poweramp would be next to the driver, so there's no real issue with running a longer (driver) signal cable to the box, since it's a low impedance signal (and if possible a coax/shielded wire). A mini switch on the driver could take care of powering up the driver. I suppose there's still a problem with switching out the pickups though. Maybe a combined driver/pickup could work completely independent from the guitar's pickups. The ebow does it, and psw's latest fiddlings with the rail pickup seem to suggest the same thing. mmm...it's like, in an ebow, it's driver coil and pickup coil seem to cancel eachother out completely as far as their combined magnetic influence on the guitar's pickups is conserned?? Somehow that makes sens, then again it doesn't... Tim psw..i'll shoot you a mail in a couple of hours

My collection I now have a humbucking driver with 2 matched coils at 4.3 ohms each. 2 mm high, 14 mm wide, 56 mm long. There's a little bit of 'spring effect' to the coils; with good quality epoxy and a slightly longer core the width can get down to 12 mm. I'd like to try internal magnets but I'm afraid even the smallest neodymiums will be to powerful, given they'll be so close to the strings? Some sort of soft ferrite or low power bar magnet would probably be ideal but it's impossible to get in these sizes. Maybe the magnetic sheet would work if cut properly..

update.. What you see is the same jig from the animation a few pages back, albeit in a less fancy form. I wanted to keep things as diy as possible; this is about as easy as it gets (scraps of wood and LOTS of tape). The jig itself is the thing indicated in red. The blocks of wood on top are only there to clear the bolt in order to make the clamping (in the vise) easier. After I've wound the driver (which is sitting between the two shiny l-profiles in the pic, notice the epoxy oozing out in the middle) I put the jig in a big vise to prevent the core from pushing the bobbins apart (the bolt and wire arrangement, seen here only provides sufficient clamping force for the winding process itself, but when you slide the side clamps in, you need something bigger, hence the vise). There's a little procedure for this: First, the side clamps (the aluminium l-profiles) are slid in (just a tad, they aren't compressing the windings yet) to space the bobbins correctly. Then, the vise gets tightened. After that, the side clamps are pushed in all the way ( I used screws) Finally, the vise is tightened some more and you wait till the epoxy sets. The winding and clamping take about 5 min total. You have to be pretty fast though, If you've never done this I wouldn't use the 5 min epoxy stuff (more like 15 minute stuff) because you have to get those clamps on before it sets. Now you can pry the thing apart. This is the hardest part. The trick is to use low-stick tape on all parts that get epoxy on them (the bobbins, the side clamps, the core). That way, if you pull the jig open (gently!), the tape will let go sooner than the epoxy, because it sticks less than the epoxy. I used vinyl tape prior to this, but it wouldn't let go..resulting in a gooey mess and broken windings. Here you can see the jig with the top bobbin removed. Notice the yellow tape on the side clamps. The yellow stuff left and right of the coil is epoxy squeeze out.The black thing is the rubber core (cut it frome some hard rubber sheet) If you look closely, you can also the two screws that clamp the sides. My wire reel is on the left. 5 € for about 10 drivers worth. Here is the jig with the side clamps removed. Note the layer of yellow low stick tape on the bobbin. The screw holes are clearly visible too. Here everything is removed (it's essentially the bottom bobbin. There's an indexing pin for the core in the middle, and two small holes for the clamping wire to go through. The grey stuff is heavy duty tape. You can add more layers of tape to control the width of the bobbin, and thus, the width of the driver. The finished product . Maybe i should make this a pic too? Damn picture rules. I'm sure psw 'll quote it . Tim