onelastgoodbye

Finally, succes on the coreless bobbinless driver front! I've managed to build a 4 ohm coil; 2mm high 7mm wide; this time utilizing a temporary core out of hard rubber (kudos to psw). I can get the width down to 6 mm, but that's as small as it goes (which is really tiny btw). Still need to wind an inverse coil for a humbucking driver. The whole dual rail driver won't be more than 13-14 mm wide. The temporary rubber bobbin just made building the jig even easier than it was (at first it had an aluminium core which was a bit tricky), I hope other people are willing to give it a try now, I'll have some pictures and details up tomorrow.It's really not that hard and winding one coil doesn't take more than 5 minutes (hey, it's 5 minute epoxy so I had to be quick ) In return you get a nice clean coil that's as small as it can physically be, and as it's a coreless driver, it's now possible to experiment with various core materials without the need to wind new coils.

I just wound a coil using the latest incarnation of the jig. Broke the wire when removing the core..again. I still think I can make it work though.

That's (iron) wire through the core yeah. I've made a test model that uses the same dimensions as in the above animation (2 x 2 mm core, 5mm overall coil width). the bobbins are clamped by a bolt + nut, like shown somewhere in my previous posts. You just make 2 loops in the wire, slide those over the bolt and tighten with the nut. Might not seem so, but that arrangement can exert quite a bit of force. In any case, it clamps tighter than my first jig, so i wouldn't worry too much about it not being strong enough. You need a small drill bit for the holes (1mm diameter), but i don't think those are that hard to find? Now the epoxy thing, that should provided you let it fully dry. IMO, Even the 5 min stuff needs about 24 hours to properly cure. If you open the jig too soon, the coil gets damaged. I now also tape (electrician's vinyl tape or clear cling film) up the bobbin and sides to prevent the epoxy from sticking to the aluminium; It's just a slight mechanical stick, but better safe than sorry. the stick is more because of bad quality epoxy and the fact the aluminium isn't perfectly smooth. In other news, I've got my hands on some very elaborate FEA (finite element analysis) software. Sort of like femm on steroids. It can do fluid mechanics, forces, temperatures, magnetic field shape and change, EMI analysis on coils and pcb's, hysteresis losses, calculate cut-off frequency,....all in 3D from cad data. Basically, it could provide scientific proof or disproof of all our theories. Problem is...this stuf is REALLY complicated mad professor complicated. you could build a lot of drivers in the time it takes to get it to work, and as we're almost there anyway...it's probably not worth it. Kinda sad because i was looking forward to using it, but it really is over my head for now.

Just a quickie. I'll edit later. I know it's a picture rule violation, but it's only 25 kB

Well, lets see... - spazzyone took a generic dual rail pickup and put a 15 w p.a amp through it, which worked great as a driver with no EMI (even works in the mid position); So me and Col got inspired to build a humbucking driver. Same principles as the thin driver, this time using two 4 ohm coils in a classic humbucking config instead of 1 8 ohm coil. It has good efficiency and really good emi rejection. A lot of variants (sp?) have been proposed, but those have yet to be built. - psw and me developed some jigs for building bobbinless coils. The latest incarnation (psw's idea) is really simple, really cheap, and can produce bobbinless, coreless coils, so experiments with different core materials can be made. -and here comes the big one...col designed a great acg circuit which basically reduces power consumption and increases efficiency. It uses a "dynamic range inverter" that increases gain when input volume is low, and decreases gain when input volume is high. psw is working on modular circuits. -there's also lots of research and reverse engineering going on; the fernandes patents, the sustainiac application notes; some great pics of sustainiac internals which googlymoogly linked to; shielding cages; FEMM diagrams; etc.. One main problem remains (as far as circuit/driver design) to be solved: there is still crostalk between driver and pickup. A slight background distortion or fizz that is leaking into the pickup signal. The source of it is still unclear. Could be the driver + pickup acting as a transformer, could be bad shielding of driver and/ or circuit, could be common grounds, could be phase-related.

Another idea, based on the tri-blade concept as to concentrate the field upward, this time using internal neodymium mags as proposed by psw two posts up. I'm kinda curious how the field would look, so if anybody wants to have a go in FEMM.. from the emg catalog: "Coils are sometimes places side by side, or stacked, but in both cases each coil is treated independently by the preamp. Instead of having the coils in series or parallel with a single output, they are electronically summed so their attributes can be controlled individually. " ... Another benefit of the internal preamp is noise reduction. By integrating the preamp into the housing, all the elements of the pickup can be shielded. By matching the coils to a high degree the low frequency hum and buzz are virtually eliminated. In addition, each EMG is housed in a composite cover cap that eliminates all other forms of interference. Mmmm..It does look more like an smd preamp. I could have sworn I read something somewhere on a cage, but as there is indeed "reasonable doubt", I'll withdraw my testimony Also found this: from the sustainiac site, on the ga-2, which is their early model also used by fernandes,... www.sustainiac.com/ga-2%20troubleshoot.pdf Battery life depends on how often the unit is turned on, and also upon the setting of the STRING VIBRATION control. Typical battery consumption is 10ma in STANDBY, and 80 ma during a low note in FUNDAMENTAL mode, which is a maximum condition. 9v alkaline batteries are typically rated at 500 ma hours. Actual battery life is usually around 15-20 hours. Don’t use regular “dry cell” batteries. Use only alkaline. Also, Nicads have short life, and only produce about 7.5 volts each. If you want to use a “wall wart” supply, you must get a REGULATED SUPPLY of 15-20 volts. Voltage must be within these limits at all times.

for reference, here's a pick from the cage in an emg:

There's a thread somewhere on diystomboxes. com on installing a fernandes sustainer that said the transformer was to step up the battery supply voltage when they went from 18 v to 9 v. Can't seem to find it now though... mehh.. From the sustainiac site: (17) Q. What is a BILATERAL DRIVER AND WHY IS IT SO SPECIAL? A. The Bilateral Driver is the new Maniac Music development for the Stealth magnetic sustainer. This driver is a patented design that virtually eliminates magnetic crosstalk into the instrument pickups. When the sustainer is installed into an existing instrument as a retrofit, a special MAGNETIC BALANCE PLATE is moved back and forth carefully by the installer to the position that gives the best magnetic null. You can hear when the positionis best, because "grunge" that is radiated by the driver and sensed by the pickups goes away at the null position. Why is this important? It is a breakthrough, because now the gain can be turned up to a level never before possible with magnetic sustainers. This results in very robust sustainer performance. It also results in being able to use the Sustainiac Stealth sustainer with any bridge pickup. Even a single-coil bridge pickup. This is a first for magnetic sustainers. (18) Q. Since the STEALTH sustainer runs on a single 9-volt battery, is it as good as an 18-volt sustainer? A. This is another question that we are getting lately. This has been going around in email chat groups. The Sustainiac Stealth sustainers produce more intense sustained string vibrations than any other magnetic sustainer, including our old Sustainiac GA-2, which ran on 18 volts. There is an understandable lack of knowledge about sustainers out there, because they are still kind of "underground" devices. Here is how magnetic sustainers are designed to be intense: By putting less (not more, but less) turns on the driver coils, you transfer more energy into the driver from a given battery voltage. This lowers the impedance. More current is drawn from the battery. This results in stronger, more intense sustained string vibration. We tried this with our old Sustainiac GA-2 sustainer, but the single 9-volt battery wore out so fast (supplied high current) that we couldn’t use the design. So, we had to add turns back on to the driver, and get the energy we needed by adding another battery to make 18 volts. That is why some competitor’s sustainers use two 9v batteries. They all copy certain critical aspects of the GA-2. Here is one of the really cool things about the new Sustainiac Stealth: We always wanted to design a sustainer that was even more intense than the GA-2, and still have decent battery life. The only way we could think to do it was to add still more batteries. Here is how we solved the problem: We discovered how to design a digital power amplifier that was four (4!) times as efficient as a conventional power amplifier when driving a magnetic transducer. With this revolutionary design, we were actually able to double the amount of energy that we deliver to the Stealth driver, but with half the battery energy that we used before in the GA-2. It's true! The Sustainiac Stealth sustainer actually puts more energy into the driver (STRONGER SUSTAIN) than any other sustainer out there, even " 18-volt" sustainers. Compare the Stealth to anything else on the market, and put a current meter in series with the battery to verify these statements.

The mid-driver is probably already possible with the rail design. I didn't get EMI 'till I held it OVER the pickup and spazzy also had good results in the mid position. I'm holding off on building more drivers as I am currently Ruby-less and I'd like to do further testing with col's circuit when it's finished. I sort of consider the driver design itself to be in it's final stages, okay well maybe after the dreaded hiss issue is resolved. what i'm saying is that, sure, efficiency certainly still be improved, but driver-wise I think we're pretty darn close already, so maybe it's time we start looking at some problems that haven't been discussed as much, like implementation. Two things I would still like to tackle are a "side" driver, if only for experiments sake; and a rail driver with internal magnets, to get it as tiny as possible. The reason I'm so keen on internal magnets is because they allow for a very thin driver when combined with the bobbinless concept (which is very doable with the proposed jigs). a driver that's 2-3 mm thickcould be placed on the guitar without any need for routing or lowering pickups. you can put it on top of a pickup, on the pickup ring, between pickups, etc.. since the new jig facilitates the use of different cores, you could ultimately provide a kit where the end-user has the choice of using either the magnet core for a stand-alone driver, or an iron core for a pickup-driver combo. Two drivers in one package! (it's called modularity in design-terminology, psw ) Factoring in EMI-reduction, do-a-bility, efficiency, implementation, the rail driver is IMO our best bet so I'm gonna focus on that direction. btw, Jeez man, this thread is flying

A quick dirty test with psw's bobbinless, core-less, and...bolt-less driver jig: instead of the bolts, there's a metal wire looped through the holes were the bolts would go, and the bolt + nut pulls the wire ends together. I tried some old guitar stringsfor the wire, but they snapped.The wooden piece on top is to distribute the clamping force more evenly. I'd put a similar block in the bottom too. It clamps well, better than my original jig, it's dirt-cheap, and the real kicker is that you can use it for thin cores. right now the former blade is 3 x 3 mm, 2 x 2 should be possible. So there you go. Do you know kraft-paper (it's german too ) ? the brown stuff they use for packaging. Should do the trick. Or you could always use dollar bills . they're cotton-based rather than cellulose-based. Much stronger than regular paper. I believe bibles are usually made of that stuff as well. Are you looking at cad-based plugins? That would be right up my alley (starting my first job as cad-designer on Monday. yay). I see there's some really good plugins for proEngineer, like Ansys/Emag but I doubt I could easily obtain that. Tim

Here's some pics that should thoroughly explain my jig: the white bits are just plastic sheet, same thickness as the core, and notched so the core fits in there the bottom bobbin is pushed into the mounting block, the core slides into the bobbin >> here the top bobbin clamps onto the top 2 mm of the core ,then the coil can be wound >> here the side clamps are screwed into the mounting block and compress the coil. here's a shot of that (with the top bobbin removed >> here I like your jigamathingie, psw. One problem i've been having with mine is that the coil ever so slightly pushes the bobbins apart while winding, which creates a small gap between the face of the bobbin and the bottom side clamping pieces. Then, when everything is clamped together, some windings get stuck in that gap...not good! Your paper trick might come in handy there. I also have an idea to replace the screws in your design, simplifying it even more, will test that tomorrow. quite right! we called it a 'robust' design in school. Say Col, you're not an industrial designer by any chance? Tim

Some observations.. I think it was portuguese . Didn't he drive the thing off of a 3 v button cell? My German is decent at best, what i could make out is that they have had 2 or 3 successfull attempts with a crude 0.2 -0.3 mm coil and a 15 watt amp, also a little gem in there somewhere. there's some pics and soundclips if you click the link in post #39 on page 3. Tey're still pretty much in the dark as to how and why things work or don't work, I'm sure they'll appreciate all the help they can get. I don't know, the more I learn from the sustainiac and fernandes designs, the more it seems to stem from some serious guesswork and extensive experimenting rather than exact science. Furthermore, the build quality of the sustainiac doesn't seem to be super-top-notch. I have great respect for these guys, and there's nothing physically wrong with the driver (looks pretty old too), but it's probably not as sophisticated as we make it out to be. The circuitry, that's something else. So, the "bobbin" air gap is more of an "ease of production" thing, I think. Especially if they're machine winding. So much easier to pop the core in afterwards. Maybe the gap between the top of both cores is of more interest to us ( but I still wouldn't make too much of it). Now, the laminating... I have done this, like Spazzy, and it doen't seem to make a big difference. Also, with the thin cores we're using there's only so many laminates you can practically use. On the other hand, it is usually easier to source (and cut) steel sheet than solid cores of suitable material and dimensions; and the laminates give you more freedom in experimenting with various core widths; so there's no real reason NOT to do it. except for the fact that the material i'm using is some sort of hardened steel, hard as hell to saw through. If I didn't know any better i'd say it was stainless One thing I'm wondering is if they drive both coils with a separate signal? there's no difference in wire gauge...so any compensation must be electronic. Also, If they're running it as a pickup, would they be using the same preamp (surely they are gonna need a preamp to beef up the signal, no)?

double post

No we haven't seen this yet...thanks very much for posting! Tim

using the calculator, turns out a 4 ohm coil @ 0.2 mm wire could be as small as 59 x 5 x 2 mm, So a dual rail driver would be about 59 x 10 x 2 mm with internal magnets (if you can ever find those). Also note how much of a difference the wire gauge makes towards the size of the coil and # of turns required. 0.23 mm wire 0.2 mm wire

mmm...lights.... My only concern with stereo driving is that the 2 coils would have to be in parallel, which means each side of, say a stereo lm386, would only be driving a 4 ohm load... i think we established early on that the lm386 was most efficient on 8 ohms loads; So you'd need either bigger coils (not-so-thin-driver) or a different amp configuration. One question: is the magnetic output of the 2 coils the same, or is one inverted (right hand rule ). Anyway, this is something I've been pondering on for a while now... I don't think the two cores are necessarily working aginst eachother. Certainly at higher frequencies/harmonics, it seems quite possible that one core would be pushing the "peak" and the other core pulling the "valley" of the same wave, or even pushing the peak of the next wavelenght, depending on the answer to my question, thus summing their (electromagnetic) output. To that extent, maybe the rail driver is already a bit of your "wave-driver". Theoretically , that would also mean that spacing of the driver cores would have considerable effect on the frequency range of the driver itself. Now, i realize, your "throw"quote is more about the shape of the magnetic shield itself and the speed and ease at which it can change. Looking at the femm diagram of my own driver, I think it could really benefit from some sort of a center laminate of inverse polarity. N-S-N, like the Tumura side drivers. As it would really focus the field upward. But then it wouldn't be humbucking anymore I guess. Or not? Aww,... confusing . Any way we could easily impement the 3rd "active shielding" blade without going for a full-out side driver? And if somebody could please do a femm analysis of a side driver, that would be great !? Tim 10 pages in 2 weeks

*slaps forehead* ofcourse! gah I'm stupid. I used that stuff to laminate my fretboard worked my way through most of the patent..lots of useful info.Some insights and corrections to my previous posts: The screws hook up to a ground wire, not the coil wires. fig. 13 and fig. 14 are not exactly the same. the first driver (13) uses a permanent magnet as a core; the second driver (14-15) uses a combination of a smaller permanent magnet and a ferromagnetic material (iron or ferrite) as a core, which should be more efficient: Further, according to the seventh embodiment, a magnetic flux producing substance is formed by a combination of a permanent magnet and a ferromagnetic substance, and thereby, efficiency of the magnetic flux producing substance is significantly developed compared with a magnetic flux producing substance made of only a permanent magnet because the magnetic reluctance of the former is smaller than that of the latter while in operation. I think you're right about the active shield thing being the most valueable part: Further, according to embodiments from the sixth to the eleventh embodiment, the electromagnetic driver has three bar type pole pieces and two magnetic flux producing substances sandwiched between them, and only the polarity of a center bar type pole piece is different from that of other bar type pole pieces on both sides, and thereby, there are several advantages in that magnetic flux is concentrated on the center portion in the neighborhood of the strings, and thereby, said magnetic flux enables a string to be efficiently excited by little electric power and so the power consumption of the dry cell battery mounted on a guitar is reduced significantly. some other interesting stuff: airgaps below the coils to prevent the field from leaking into the trem cavity: Further, according to an electromagnetic driver of a device for sustaining the vibration of a string as shown in the eighth embodiment, a Tremolo device, a spring and a metal screw form a magnetic circuit and so-called magnetic feedback is produced by magnetic flux emitted from the bottom of the electromagnetic driver through said metal devices. Downward deflecting slits prevent the production of the magnetic feedback by properly distributing downward magnetic flux. mmm...did he just patent bobbinless drivers here? beat me to it Furthermore, there is a merit in that an electromagnetic driver of this embodiment is basically formed only by processing a bar type pole piece and a magnetic flux producing substance. Therefore, there is no need of plastic mold elements such as a bobbin in the electromagnetic driver and so various widths, lengths and shapes of the electromagnetic driver can be easily realized. Also, the production of the electromagnetic driver is completed by substantially fixing the magnetic flux producing substance on the bar type pole piece with a screw instead of assembling several parts, e.g., a permanent, a base plate and a cover, into a electromagnetic driver after a coil is wound around a bobbin. Therefore, the electromagnetic driver of this embodiment is very convenient for inexpensive mass production thereof. Accordingly the coil of the electromagnetic driver 17 uses a copper wire with a diameter of 0.3 mm larger than that of the electromagnetic pickup 8 and about 200 turns of the wire is wound, therefore the electromagnetic driver 17 has small electric resistance about 7 ohm and low power-loss characteristics. that explains the big coils...BIG difference between 0.2 and 0.3 wire...see page 103 of this thread . Col, you'll like this one... A driving current used to excite a string in such an excitation system is usually about 50 mA, and so the emission efficiency of driving magnetic energy is very important so as to prevent the necessity of frequently changing the dry cell battery.

that's exactly what I had in mind (only a lot smaller)! if you look at fig.14 and 15, which are the sectional view and top view of the same driver, you can see that the magnets (indicated by nr. 83) are sitting inside the coils, inbetween those two screws that are used to hold the whole thing together. Polarity of the magnets must be horizontal. Seems like those screws also function as a connection for the coil leads?

Afraid so.. the epoxy sort of sticks to the aluminium (which it shouldn't be doing, damn disobedient epoxy). It's just a little mechanical stick, but enough to break the windings at the core edges when i unclamp the jig. Probably neet to let it cure a little longer, or use a cheap release agent (vinyl tape, maybe shoe polish?) I got a bit carried away there. It got late yesterday night . I'm aware of the solenoid thing and how a coil with core inserted is dramatically more effecient than a coreless coil, yet somehow managed to forget that little fact (never was much of an engineer, i'm more like a mad professor ). Yeah I read about the polarities..I'm having a bit of trouble imagining how that configuration affects the magnetic field through the coils. Does one coil still 'see' north polarity, the other south (to take care of the humbucking)? right hand rule and all that stuff... One thing I should note is I was thinking more of a configuration like the q-tuner, with the magnets inside the coils (seems like that's what he's doing), so the coils wouldn't exactly be core-less. Not sure on how the magnets are polarised though. Vertically or horizontally? btw, I'm also pretty convinced our 'regular' rail driver is the way to go (hard enough to build as it is), but I figured these side coils might be worth exploring so thought i'd "throw it into the group" (is that a valid saying in english? it is in dutch ). If someone can shed some light on the polarity thing, I'd might just be able to make something really simple (construction wise) using the u-bar: winding two coils around the magnet and putting that in the u-bar. I'd like to try the u-bar for shielding purposes but I can oly put two coils in if they're on their sides. Anyway, as Primal said, efficiency is probably gonna be pretty bad with side coils anyway. Here's another brainteaser: I don't suppose anybody has ever tried bismuth as a shield?

wound another coil; had another short so I did a little research instead: http://www.q-tuner.com/index.shtml These pickups have intrigued me for a while, but I'm just now starting to understand what it's all about. I'm gonna try to build a driver in a similar configuration, not in the least because it looks so cool (I love a product that displays it's inner functionality). Here's a little bit of my train of thought ( if you don't like blabber, you've been warned ) looking at the FEMM diagram of my own coil a few posts back, it suddenly struck me that the inner windings of the coils (the windings that sit in between the core) sense a stronger magnetic field than the outer windings, and thus probably put out a stronger voltage when the field is disrupted. So why not place the whole coil in between the cores? mmm...and to make things more compact, in width (I've suddenly become a follower of the narrow driver theory) we could rotate the coils 90 degrees, you know, put them on their sides. Electromagnetically speaking, there's no reason why a coil should be wound around the core, or why a core should be physically connected to the magnet. For a current to be induced, the coil merely needs to sit in the magnetc FIELD of the magnet, parallel to the core (as in not perpendicular). mmm...didn't fernandez put their early drivers on their side (the coils, that is)? now why'd they do that? Ooo...(eureka!) it's probably to reduce electromagnetic interference with the pickup; just like why they mount amp transformers at straight angles to one another. Magnetic fields placed at 90 degrees have little to no influence to each other. Now, in the Fernandes sustainer's case, the fields of pickup and driver would still be orientated the same way, but atleast the coils of driver and pickup would not be, so the transformer effect would be minimal...i think..gah, need to find my engineering handbook..it's lying around here somewhere (yeah, I actually tried engineering some 7 years ago, we spent a whole semester on electromagnetics. can't remember crap of it though). So what do we have. 2 coils on their side each 2 mm thick. 2 blades each 2 mm thick (maybe we could get away with 1 mm). So that's a total width of 6 - 8 mm. Cool. 'height' of the coil would be about 5mm, if I adapt the jig maybe even less. Leaves us with the biggest hurdle, the magnets. I've got some u-channel iron bar here, bet there's some nifty neodymium mag configuration possibilities there..

Here you go: lousy big ass ceramic...

I would not use MDF for GUITAR speaker cabinets. while it is a decent material for regular speaker cabinets, as it's a good sound absorber, guitar cabinets are different from hifi speaker enclosures. Domestic speaker cabinets need to absorb and deaden the sound that is projected from the back of the speaker cone. that way the enclosure itself can not generate any unwanted noises and colour the 'ideal' sound that is projected from the front of the speaker cone. The ideal hifi enclosure is the one you can't hear. Guitar speaker cabinets however, are required to colour the sound.They derive their unique sound from being prone to resonant frequencies (big no-no for hifi cabinets), which basically means they vibrate along at certain frequencies; usually percieved as "boominess" or "wooomph". They are essentially very poorly designed enclosures (in terms of fidelity), but it's what our ears have historically grown to appreciate as "the guitar sound". MDF is usually only used for the front baffle in cheaper cabinets, higher-end stuff uses 3/4 birch (void-free) plywood all round. MDF is sawdust glued and pressed together and will deaden your sound severely, taking away from the "liveliness" which is essential in a good guitar cab. Same reason we don't use MDF for guitars. Another reason you don't want to use MDF, is because it has no structural strength at all. It's very easy to tear the corners and will not withstand heavy use. I have plans for a marshall 1960a slant cab. If you're interested, PM me and i'll put it up. Tim

I vote bottoms too. Your body has a general 'downward' movement going (top left to bottom right) which is nicely balanced by the 'upward' (bottom left to top right) movement of the headstock. tou might want to narrow the headstock just a tad so you can have straight string pull, which would make it look less cluttered. I kinda like how the bottom horn looks like a sword \m/

Heh. It makes for a cool effect though, my 10 watt amp was rattling the strings like mad today. But seriously, you wouldn't want the strings to bounce the fretboard no. That's why you don't want pump too many watts into the driver. The ruby is 1/2 -1 watt max and that's plenty enough. Exactly. It's not just a matter of using a y-cord. Well, you could, but then there's issues of loading, weaker signal, the driver signal leaking into the amplifier signal,...to solve these issues, the split signal needs to be pre-amped and buffered (or something like that ). yeah i'm a bit worried about the efficiency too. Like I said though, i have a crappy testing setup and a few loose connections so the performance was ...intermittant at best. Whenever it did work, It was pretty impressive though, the EMI rejection really cleaned up the signal. Ferocious little bugger too (okay that was probably the amp). I'm curious to see what results Col comes up with. Should give us a better idea of core thickness and spacing too. Mine are 2mm wide with 4mm between them (did i say it's tiny yet? ) Oh PSW, you seen this yet? http://www.vellemanusa.com/us/enu/product/view/?id=521723# Velleman is actually a belgian company. A former teacher of mine worked there. I'm intrigued by the low part count ...you should check ot the datasheet...it uses a TDA726A opamp, may be an alternative for the lm368?

I should note that I've been using laminated cores in most of my drivers, doesnt make a big difference. there's probably a rule somewhere for x number of laminations for y core width, but as the cores are so thin, you can only use 3-4 laminates maximum, so I think there's little benefit in that (EMI wise). I should also note, now the EMI is gone, there seems to be a lot less interference between strings; you can keep one note going without the constant dampening of the other strings.