Emily Posted March 17, 2009 Report Share Posted March 17, 2009 I have two potentially n00bish questions to ask: 1) can a driver for a 7-string guitar be built, using pretty much the same procedure, but only a wider magnet? Or are there some specifics? 2) if I were to place the driver INSIDE of the body so that it's not visible, would it still work? Because the build that I'm going for will be having a bridge pickup only; and I NEVER use neck pickups, nor find them aesthetically pleasing (opinions, opinions...), so I'd like to keep that area "clean" on my guitar. My apologies if these have already been answered, but I don't think it'd be feasible for me to go through all 295 pages of this thread to find the answers to these (atleast what I think) utterly stupid questions. Link to comment Share on other sites More sharing options...
psw Posted March 17, 2009 Author Report Share Posted March 17, 2009 Hi. I just want to pass on something that is working well for me,... in the area of the stand- alone driver. as in Pete's Telecaster. I have been winding the magnet itself. The neodymium ones . No steel,. no bobbins. just the magnet and the winding. It makes a very small package. . There are a couple tricks to know, but the procedure is actually very easy... If there is interest, I will elaborate. I haven't tried these drivers with a 386 amp, so I would be curious to to see how they compare in sound to Pete's thin style driver. But it seems to me that the principle is the same.. They do great in my setup. And they may have some advantages...:ease of construction, size , etc. Al Hi... I tried this on a number of occasions and again on the tele driver but with no success. I've discussed the drawbacks and limitations of neomagnets before. The temptation to use them is great, but there are a lot of problems with them for this application. I'm not sure from your post if you have made the driver and it is working well...or that you just were able to make such a driver. Onelastgoodbye/tim made such a driver without bobbins many years ago but apparently did not work for him and I have had similar problems. Certainly you can make such devices, but the proof is in how they work. I have even had trouble with ceramic magnet cored drivers for some reason...most likely related to the dimensions of the stock magnets I have been forced to use....however there may be something to the idea of the coil being substantially over one pole (the end of the magnetic field) rather than around both north and south equally in terms of pushing out magnetic energy. But...more details are always welcome... pete Link to comment Share on other sites More sharing options...
psw Posted March 17, 2009 Author Report Share Posted March 17, 2009 Welcome to PG and the sustainer thread Emily... My apologies if these have already been answered, but I don't think it'd be feasible for me to go through all 295 pages of this thread to find the answers to these (atleast what I think) utterly stupid questions. No, you have done the right thing...this thread is kind of a Q&A on the project and what people are up to and thinking about, reading it can make things more confusing. Do try reading the various tutorials and stuff linked in my signature and generally around the place though. I have two potentially n00bish questions to ask: 1) can a driver for a 7-string guitar be built, using pretty much the same procedure, but only a wider magnet? Or are there some specifics? 2) if I were to place the driver INSIDE of the body so that it's not visible, would it still work? Because the build that I'm going for will be having a bridge pickup only; and I NEVER use neck pickups, nor find them aesthetically pleasing (opinions, opinions...), so I'd like to keep that area "clean" on my guitar. 1) Yes. I believe there shouldn't be too much of a problem although we have yet to have someone actually go all the way and do it. The only potential problem is that the coil will be less because there will be less turns to make up the same resistance due to the extra length each turn will make. 2) No. While you can save yourself a lot of problems by only having the bridge pickup (bypass switching, etc) the driver needs to be extremely close, generally as close as possible to the strings. With care it can be made pretty small and inconspicuous and potentially coloured to match a scratchplate or the guitar colour or appear as an extension of the neck (visually) it does need to be there! Looking at the Blueteleful Telecaster thread may give you an idea of how small a driver with conventional construction could be. Epoxy is not advised by me in the first instance, but even with bobbins they can be made very small by hand. The whole thing could be molded in some kind of epoxy filler material and painted or coloured perhaps to disguise it and make it a little more attractive... On my tele, I chose to leave it clear...but I could have molded it to the shape of the next door neck pickup so it could have looked like an HB in there....i could have used coloured epoxy so that you wouldn't see the insides...but I thought this worked well for the guitar and to illustrate what was in the thing and how it was constructed. Anyway...start out with the tutorials and stuff and ask as you please... pete Link to comment Share on other sites More sharing options...
al s. Posted March 17, 2009 Report Share Posted March 17, 2009 (edited) Hi. Re: the drivers with the neodymium magnets. They work great. With the exception of a few dead spots on the fretboard they drive all the strings to feedback. I've experimented with different sized magnets. I've used these with success: http://www.magnet4less.com/product_info.ph...;products_id=33 1/8 th inch thick. can be placed farther from the strings .. about the same distance as a pickup http://www.kjmagnetics.com/proddetail.asp?prod=BX021 1/16 thick! must be closer to the strings AL Edited June 13, 2009 by al s. Link to comment Share on other sites More sharing options...
Truth_David Posted March 17, 2009 Report Share Posted March 17, 2009 I think CurtisA tried it as an experiment. I played around a bit with the idea. Thanks - how can I get in touch with Curtis - I haven't seen any recent posts from him? There are a number of problems...one is acoustic strings have windings that are non-magnetic...it relies on the steel cores to work. Another problem is the high harmonic output and characteristics of piezo pickup systems. Despite that the e-Bow does work, albeit picking up somewhat slowly, so I see no reason why the sustainer should not work at least as well.....another solution is simply to change the strings for steel or nickel - the tone might suffer a little, but it's roundabouts and swings. An up side is that the piezo system will already be preamped...the piezos are not magnetic, but there can still be some interference. The piezo system currently fitted to one of my guitars has no preamp, I am currently looking into a suitable preamp circuit for it which would provide at least a volume and tone control, but preferably something a little more versatile - except that I am not about to cut a slot out of the guitar to fit it. This is another reason to get the electronics off the guitar, but if the stereo phantom power idea is a no-go, I will have to find another solution. I predict some other problems with an acoustic guitar. With the electric we are dealing largely with the vibration of the strings, on an acoustic the top too is vibrating. As the strings are being driven, these too will be driving the top (and potentially vibrating the driver and pickup/s) and I suspect that the result could be a kind of "howl" like feedback at any decent volume. Perhaps I should add, just to be clear, that in all probability I will not be amplifying the acoustic, it really is unnecessary at the volume at which I am playing it presently - the e-Bow easily provides sufficient volume acoustically to provide the effect I am looking for, which is what I find so attractive about it (and that certainly does not squeal, although the strings do occasionally bang into the frets if I'm not really careful). If I really needed to, I see no reason why once I have the acoustic sustainer working, I should not fit steel strings and a GK hex p/up, then simply use my VG-99 to process the signal into whatever I need it to be - at volume. The downside of that is that one would need to be playing pretty loud when using any alternate virtual tuning not to hear the actual tuning of the strings - in that respect a solid body offers significant benefits over an acoustic (unless I were to grab a Variax acoustic, which would be far quieter, but then it would be useless for the acoustic sustainer when unamplified). So...not a lot of work done on this really, I suspect like bass sustainers the appeal is limited...but it certainly isn't an "easy way"... Well, I see no reason to be negative about it - where there's a will there's a way, so they say. So if there is anyone here who would like to add their input, two heads are better than one. I would like to hear from anyone interested in this concept please. On the tillman. This is a well tried decent pickup design...it could work in place of the fetzer but still requires a poweramp circuit to drive the driver. I believe that Tillman also recommends an LM386 circuit or similar, I don't remember now offhand. We have discussed remote power...there are even products about like the x-bat. However, the sustainer is a different beast to a low current preamp. Running high power alongside the signal and sharing the earth all along the cable may well cause problems. Certainly have the circuitry remote and running the driver leads up the lead poses significant problems. But even power in the lead may cause significant noise and pop issues. I started working on something, but the project wasn't completed. It was actually quite costly to make a stereo lead of any really length and not the most practical solution compared to accommodating a battery. I'd still like to see someone fully explore this aspect...there's a bit about on this thread for reference. If the battery needed to be fitted to an acoustic though, that might make things more difficult, although perhaps one could fit a battery within the sound hole or find a similar solution, but I don't relish the idea of having to loosen off the strings and dig around inside the sound hole every time the battery needs to be recharged. David L pete Link to comment Share on other sites More sharing options...
psw Posted March 17, 2009 Author Report Share Posted March 17, 2009 That's great AL The difference between the things I was experimenting with was that I could only get my hands on small discs. By using a bar but very thin, there would be much better properties and clearly work a lot better. The big mistake some have used have been far to large a magnet...I estimated 1/8" disc to have the magnetisim of a typical anico pole in a strat pickup, some often try to use much loarger and many of them which is way too strong! You have again proven the worth of the thin coil design and appear to have wound them extremely well...apparently confirming my results and that on the tele. I'm sure people would like more detail on how you wound and potted them, bobbins and such...and what kind of circuits you are using. Perhaps even some audio. I would seriously caution people against cutting or grinding neodyminium magnets, and magnets generally. Not only can this demagnetize things, the pieces and filings form tiny magnets that can fly off with magnetic repulsion especially if it breaks or is squeezed as say in a vice or hit say with a hammer. A pair of the small bar magnets though could well provide sufficient for a core without such processing...taking care about magnetic direction. But, well done...the secret really is in the use of the small bar shaped magnets and the quality of your winding... pete Link to comment Share on other sites More sharing options...
col Posted March 18, 2009 Report Share Posted March 18, 2009 Hi. Re: the drivers with the neodymium magnets. They work great. With the exception of a few dead spots on the fretboard they drive all the strings to feedback. I've experimented with different sized magnets. I've used these with success: http://www.magnet4less.com/product_info.ph...;products_id=33 1/8 th inch thick. can be placed farther from the strings .. about the same distance as a pickup http://www.kjmagnetics.com/proddetail.asp?prod=BX021 1/16 thick! very responsive. must be closer to the strings http://www.kjmagnetics.com/proddetail.asp?prod=BZ082 I cut this down to 1/8 x 1/8 x 3 inches. One piece. Easier to work with. That's a great source of magnets. I wish there was somewhere in the UK with such a good range and good prices. There are a few ideas I want to try out that need a very compact magnet, however after adding shipping and tax, I'm not sure if I can justify the expense just now. Link to comment Share on other sites More sharing options...
psw Posted March 18, 2009 Author Report Share Posted March 18, 2009 Sorry if i come off negative, we all have our own way of communicating...and experience with these things The ebow will work on an acoustic because it has a self contained driver and magnetic pickup...it will drive the steel strings. However, without the magnetic pickup it will not have quite the same effects as it can't draw on the neck pickups magnetism for instance. Thanks - how can I get in touch with Curtis - I haven't seen any recent posts from him? No, I haven't seen anything of curtisA since he was making a bilateral design and hoping to build it into the middle position. It has been a long time, but many people have come and gone over the years. You could try digging around to see the post where it was mentioned. Basically it was a passing comment on how he took the circuit and driver that worked for the electric in test mode and used an electroacoustic to drive it with some positive results...this is far from properly implementing it but does indicate that it should work. The phantom power has problems but not inconceivable that it should work. Mainly it is running the power all along the line of the signal and the resultant pops or noise when the power is drawn at different levels or turned off. On a very light always on preamp like the tillman, this isn't an issue. Putting the sustainer circuit off board and running the driver signals is definitely problematic...see my "sustain box" testing unit for instance which is just that really. Perhaps I should add, just to be clear, that in all probability I will not be amplifying the acoustic, it really is unnecessary at the volume at which I am playing it presently It really doesn't matter if it is amplified as the sustainer circuit is an amplifier. So there is a risk that a vibrating top may set up an oscillating feedback effect...this will not allow for drive. Basically we are talking about squeal, or possibley howl...even if the thing is not plugged in or you add a magnetic synth pickup, if these symptoms exist, even if they are not "heard" then it won't work. The likelihood is that on an acoustic you would perhaps "hear" it acoustically...but it would still interfere with the effect. But, that is not to say that it couldn't be done. A non-preamped piezo is really going to be setting you up for problems. At the very least you will need to match the impedance for the sustainer circuit so a preamp of some kind (at least something simple like a fetzer) is going to be essential. Further, the harmonic content of a piezo and its tendency to cause noise and high transients when not filtered is also going to create a lot of headaches. At least that is an informed opinion...I imagine that you can try it and find out for yourself of course. A lot of it is presumption until people do a lot more work in doing it in the real world. But it is not simply being negative, it is informed at least to some degree...the positives are how you will overcome these obstacles...so preamping, filtering and noise reduction of piezos are some of the strategies that I have mentioned and immediately come to mind. I see no reason why once I have the acoustic sustainer working, I should not fit steel strings and a GK hex p/up, then simply use my VG-99 to process the signal into whatever I need it to be - at volume. May be...although, the GK is a magnetic pickup and if there is distortions due to magnetic coupling in the system (ie "fizz") it may not be that happy with the signal that it is getting. And of course, an acoustic guitar at any volume is susceptible to natural feedback due to the vibrating top and so limited in the volumes that it can operate at. Anyway, if people choose to take my observations as negative, so be it...with all these things they need to be tried. When making comments about "easy way" I know some are seeking solutions or alternatives to what is possible. Maybe you want an acoustic guitar sustainer and maybe you can achieve that...but it doesn't appear to be the optimum instrument for a synth controller which seems to be the direction you are really headed. Why you then wouldn't be proceeding in the more tried and tested paths set before you to achieve this aim I can only presume, I suppose. Personally am a little wary about people adapting things into unknown territory until they have the basics down successful...either they are seeking something more than what the current state of play has to offer or they are seeking an "easier way"...but then maybe I am missing something. best thing is to probably try it...build a driver, make a circuit, hook it up and see what happens! pete Link to comment Share on other sites More sharing options...
Truth_David Posted March 18, 2009 Report Share Posted March 18, 2009 First of all, my comment wasn't directed at you psersonally, it was more a question of not wanting to have the idea written off, simply because no-one else seems interested in the idea. ...However, without the magnetic pickup it will not have quite the same effects as it can't draw on the neck pickups magnetism for instance.In other words there will be less powerful sustain? It was your test unit and the hi-tec designs in virtual format that got me interested in the idea - it seemed so elegant to me and would not tie us to a single instrument. I had already at that point envisioned having the Variax guts off-board, but the idea of the same thing geared toward a sustainer unit really captured my imagination, for similar reasons I think that once having heard the effect of an e-Bow on an acoustic, many who presently do not see the point might change their mind. There is something so organic to the sound thus produced that I see it as an entirely different beast from the electric guitar application. For one thing it does not produce distortion, and the sound is more natural, like a bowed string, almost like a viola or cello. It could add an entirely different dimension to the sound of an acoustic guitar. I agree with you completely regarding having a non-preamped piezo, in fact having a piezo fitted with no preamp, and thus neither volume control nor EQ is extremely limiting. In fact it was only by combining the piezo output with a Yamaha MS2 multi-effects processor that I heard what should be coming out of the guitar, but that still does not give me guitar mounted controls. As I say, I am not about to cut out a hole in my acoustic guitar for a preamp module, but perhaps something akin to your test unit which could later be combined with the necessary sustainer circuitry would be a possible direction. The enclosure could be fitted to the guitar strap, or possibly something could be made up along the lines of the Roland GK-3 mounting plate, which is screwed to the strap button.That would allow the unit to be mounted without it having to affect the acoustic sound of the guitar, as the enclosure need not then actually be in contact with the top of the guitar, although that would require a sturdy mounting plate. In such a case it would be less necessary to use phantom power, because the battery would be more easily accessible within the enclosure. Being able to then transfer the setup to an electric guitar would be the icing on the cake.... I just don't want to see this idea shot down in flames before it has really been tried . Again, after having followed this thread for some time I understand where you are coming from, and in many respects you are correct... I agree with your statement, but ultimately I also want to have the system working with my electric guitar, in order to overcome the limitations we have discussed. But it is paramount for me to be able to also use this totally separately with my acoustic guitar - I was looking as the GK application as a possible bonus, because I know that players like Al di Meola use such a setup with the VG-8 and VG-99. As to my reasons for not proceeding in the more tried and tested paths, for one thing, I have been advised that for an acoustic application the tried and tested approach is not likely to work, because :for that application, the best would be a preamp and a piezo-electric p/up that was capable of making the guitar vibrate, as a coil such as those proposed on the forum for an acoustic guitar would be insufficient, because the sounds produced by a sustainer are not the same as those produced by playing with a pick, but more like a violin, too continuous, with no emphasis on the attack produced by a plectrum. In any case, it would also be a question of trying it out as a replacement for a p/up with a microphone preamp, and the LM386 amplifier proposed by the forum, which is sufficient for a thin coil of 8 Ohms. Because the strings on an acoustic are also steel, it will also get them to vibrate, it will be enough just to try and see whether the sound is adequate , and if you like it, one could then add something more complicated with the ACG in order to reduce battery drain. Another approach would be to use the same circuit but substitute a piezo-electric p/up for the driver coil and try it out to see how it works in different positions on the guitar in order to determine where the notes vibrate the most strongly. Agreed, the best thing is try it, but right now I need to establish precisely what is needed, in the light of the above quote, so that I can acquire all the necessary parts and materials. David L pete Link to comment Share on other sites More sharing options...
psw Posted March 18, 2009 Author Report Share Posted March 18, 2009 (edited) Well, the answers are only going to be found through experimentation. The principle is sound, but the devil is in the details. With the "sustain box" things, this went no further (at least from my perspective) because of the multitude of practical problems which become apparent when you think it through with conventional guitars or unless significant (and unlikely) progress was made in the driver mechanism that avoided any detrimental magnetic interactions (most likely a physical impossibility). That's not being negative...obviously if I put on my 'speculative hat' and work in abstract ideals...eg, 'I'd like to see this as a stick on no modification portable device for any instrument'...'here's what I envision and how I am working towards that aim'..it all sounds and can "virtually" look great. However when you consider the physics and the wiring for bypassing, the enormous variation in instruments, different user exceptions, skill and abilities of the people having to make such a thing...and most importantly actually physically build these things...you will come to see the impracticability or likely impossibility of such a thing. But, maybe I have missed something. The ebow for instance is exactly that kind of self contained device. My telecaster gets as close as I have been able to make it...with more work, you could make things more compact perhaps, like Als drivers...but the installation issues are not addressed. But as I say, until someone or more likely yourself put in many hours of experimentation this kind of thing will get no closer...that is the truth I'm afraid. I personally have done more than enough work like this to know the pitfalls, but to survive the endurance and frustrations you have to be highly motivated and do the work required...at some point there may need to be an acknowledgment that some things are not possible...or that at least the possibility is outside of one's personal reach. That's not a reason not to pursue something, but it is a quest that requires setting out, a lot of hard travel and no guarantee of the destination. So, time to set out on the road to achieving your goals... pete Ummm....is that quote from me? Another approach would be to use the same circuit but substitute a piezo-electric p/up for the driver coil You won't make a piezo driver...at least in any way I have attempted or considered. The strings are driven by elctromagnetic energy...piezo's are not magnetic, so without direct contact with the strings (which has other significant problems) they are complete fancy. If that was me, I am very disappointed in myself if I said or meant that! Edited March 18, 2009 by psw Link to comment Share on other sites More sharing options...
al s. Posted March 19, 2009 Report Share Posted March 19, 2009 HI. There are some pic in the link of making a driver from a magnet. They will save a lot of explaining http://s651.photobucket.com/albums/uu234/alex1111115/ All that is necessary are two steel bars about 3/4 inch by 3 inches about 1/8 thick. Wrap the bars with aluminum foil ( to release the epoxy) *Then sandwich the magnet pieces between the bars.* The strength of the magnets will hold the whole sandwich together while it is wrapped. Finally, clamp the sandwich and if necessary massage the wire into a good shape before the epoxy dries. **This is the tricky part. The magnets must have a pole face against the steel. Check by holding a steel pin to see that it is attracted to the center of the face...not the side. Also important. the ends of the magnets must REPEL. Fortunately their attraction to the steel will hold them in place despite this repulsion. And most important. .. be sure the magnets are centered and in in line after they are sandwiched, before they are wrapped.. they tend to want to get crooked. I told you it was easy! Al Link to comment Share on other sites More sharing options...
psw Posted March 19, 2009 Author Report Share Posted March 19, 2009 This is very elaborate, i guess with a machine winding the epoxy doesn't set too fast. I used a similar technique for my bilateral driver with magnets inside... Hard to see, but two coils with internal magnets, metal between, and I arranged them so when they split apart, they were automatically wired in series... Instead of foil, i use stuff like pvc tape to stop everything sticking. Good to see how you pushed the sides in...a lot of people don't do this...which is why yours look so much neater than some. Well done...hope this inspires others! pete Link to comment Share on other sites More sharing options...
Truth_David Posted March 19, 2009 Report Share Posted March 19, 2009 With the "sustain box" things, this went no further (at least from my perspective) because of the multitude of practical problems which become apparent when you think it through with conventional guitars or unless significant (and unlikely) progress was made in the driver mechanism that avoided any detrimental magnetic interactions (most likely a physical impossibility). Perhaps that is the key - 'conventional guitars' .....the idea of using a guitar which only uses a hex p/ups and no mags should make all this bypass problem far simpler. I don't need it to work with a mag p/up because as I mentioned, apart from the acoustic I only use the VG-99 simulations now, I really have no use for mag p/ups, any more than I need to use a guitar amp. I am one of many who have found that the VG-99 modeling is really so accurate that it really can do more or less anything you are capable of programming. But once again, I beg to differ - it is not a synth, even though it can drive a midi synth. That's not being negative...obviously if I put on my 'speculative hat' and work in abstract ideals...eg, 'I'd like to see this as a stick on no modification portable device for any instrument'...'here's what I envision and how I am working towards that aim'..it all sounds and can "virtually" look great. I think that everyone acknowledges the work you have done on this project, but respectfully, I think from time to time it is necessary to use different approaches, looking at the problem from different perspectives. I realize that many have been tried and have failed, many claims have been made but not substantiated, such as our recent poster claiming to have combined an EMG81 with an EMG Select single coil as a driver. Perhaps he really did get that to work - who knows? What saddens me is that no-one else is even interested enough to provide a different perspective, leaving you to provide all the answers. However when you consider the physics and the wiring for bypassing, the enormous variation in instruments, different user exceptions, skill and abilities of the people having to make such a thing...and most importantly actually physically build these things...you will come to see the impracticability or likely impossibility of such a thing. I think that we need to acknowledge that zfrittz6's idea for switching using a micro switch with a standard 5 way switch was a stroke of genius, and it would have enabled us to avoid this problem entirely. But, maybe I have missed something. The ebow for instance is exactly that kind of self contained device. Yes, that is the point.....who would have thought it possible to produce such a device as a stand alone unit, and so compact? It took a man with the vision and the necessary technical and electronics skills to accomplish this goal. No doubt he had an idea of what he desired to create, then put those skills to use until he found a way to succeed. I feel that it is a shame that he stopped there, because I think that it has simply not reached its full potential. It does what it does well, but is limited, as we all know, otherwise we would not be trying to produce what is essentially an e-Bow for all the strings. Perhaps we should be looking into combining the necessary components in a similar way. After all, another point I would like to make is that it seems everyone here has been relying upon interaction with existing p/ups on the instrument, whereas the e-Bow needs nothing more than a set of metal strings on an instrument in order to do its work. I wonder whether anyone has tried somehow extending the magnetic field of an e-Bow like device, so as to make it affect all the strings at once? Perhaps another approach would be to have it mounted above rather than below the strings, and have it moveable, so that it could slide along the path of the strings in order to capture the nodes where the harmonics are richest, just as one can do with the e-Bow? I realize that this might sound far too simplistic, but perhaps it might get people thinking in new directions. I remember a US made guitar that had a single sliding p/up, I am getting it confused with the Travis Bean which came out about the same time (and I believe both had aluminium necks), that worked very well, because one could slide the p/ups beneath the strings until one found the optimum tone, so with a single guitar and a single p/ups there was a great deal of tonal variation possible. Perhaps that technology could also be applied to the driver? (obviously not if the guitar has a Strat or LP configuration). Or perhaps this idea could be used on a project guitar, in order to define where precisely the best position would be for the driver in relation to another p/up. My telecaster gets as close as I have been able to make it...with more work, you could make things more compact perhaps, like Als drivers...but the installation issues are not addressed. True, so Al, what's your take on the installation issues, what can you come up with? That's not a reason not to pursue something, but it is a quest that requires setting out, a lot of hard travel and no guarantee of the destination. So, time to set out on the road to achieving your goals... Well, with Quantum Mechanics breaking all the rules and laws of Physics as we thought we knew it, perhaps it really depends upon how we look at the problem. pete Ummm....is that quote from me? Another approach would be to use the same circuit but substitute a piezo-electric p/up for the driver coil What about the rest of the quote? - that is only the continuation of an observation, no more than thinking out loud, I would guess. But no that was from another friend of mine who was looking at the project from the standpoint of an electronics engineer. He saw it as being easier to develop a sustainer for an acoustic instrument because automatically it avoided the problem with wiring and having to bypass all but one of the p/ups, but he felt that a thin coil driver would not be appropriate. You won't make a piezo driver...at least in any way I have attempted or considered. The strings are driven by elctromagnetic energy...piezo's are not magnetic, so without direct contact with the strings (which has other significant problems) they are complete fancy. If that was me, I am very disappointed in myself if I said or meant that! No, it wasn't you....but thanks for clarifying that. David L Link to comment Share on other sites More sharing options...
psw Posted March 19, 2009 Author Report Share Posted March 19, 2009 But once again, I beg to differ - it is not a synth, even though it can drive a midi synth. I didn't say it was a synth in that quote...however in a previous post... Maybe you want an acoustic guitar sustainer and maybe you can achieve that...but it doesn't appear to be the optimum instrument for a synth controller which seems to be the direction you are really headed. the GK is often referred to as a synth controller...but if you just see yourself past that and back to basics... The point is that these things are small magnetic pickups...in fact, six individual ones...and my point was that it is just as susceptible to EMI effects. Additionally, these things may well adversely affect tracking and the A/D converters that the signal needs to go through for the digital processing. What you use the thing for doesn't change what it is! There is no need to try and convince anyone but yourself how good digital modeling is for you...it's irrelevant to this project. However when you consider the physics and the wiring for bypassing, the enormous variation in instruments, different user exceptions, skill and abilities of the people having to make such a thing...and most importantly actually physically build these things...you will come to see the impracticability or likely impossibility of such a thing. I think that we need to acknowledge that zfrittz6's idea for switching using a micro switch with a standard 5 way switch was a stroke of genius, and it would have enabled us to avoid this problem entirely. Hmmm...what ever happened to zfrittz6? I think you over estimate that because of the claims made for it. A 4p5t superswitch is the ideal way of using a selector. The additional micro switch is a neat idea that I have used for various things for a long time (there is even one on the tele and on several hex drivers over the years) however there were significant things overlooked that it didn't address...most likely that as I recall it was never done! Consider the switching I have had to implement with any multipickup guitar. I have explained the problem on other forums that have come up with different solutions and I have obviously spent countless hours on these things as I consider it to be the major problem and no one else is doing a lot of work on it. However, there is a solution, several...and I have discussed it! zfrittz6's idea was to use a micro switch at one selector position to turn power on to the sustainer circuit when the bridge pickup is selected. Sounds good...however, on any conventional strat or multipickup guitar, the grounds to all the pickups will still be connected and this is not an adequate switching circuit. I realize that many have been tried and have failed, many claims have been made but not substantiated, such as our recent poster claiming to have combined an EMG81 with an EMG Select single coil as a driver. Perhaps he really did get that to work - who knows? What saddens me is that no-one else is even interested enough to provide a different perspective, leaving you to provide all the answers. Well...maybe people are inhibited, maybe I have answered the question from my experience adequately, maybe people just don't know what to think. Maybe he got that kind of thing to work...but by any stretch it must be extremely inefficient due to impedance issues (which Micheal Brooks seemed to address on the original "infinite guitar" with a giant transformer). Spazzyone did very much the same thing a few years earlier with a lot of power and a rail pickup. I did, and I am sure many have over the years, considered the sustainer concept, got an old pickup and subjected it to a lot of power...cause it's a coil right, so you should get sustain! However...there are things that might give you the appearance that such things will work. There is a heavily distorted compression effect that can occur (that we call "fizz" in the mildest form and try and eliminate) that sounds like sustain. As long as the string is vibrating you get a massive volume as the driver and pickup couple as in a transformer. The ebow also exploits this as the driver is moved towards the pickup and feeds it's signal into the signal chain. However, this effect is not sustain and once the string stops vibrating it is most unattractive, the system tends to oscillate (squeal) when there is no signal...but all this is often ignored because the system is so loud that you often get infinite sustain from this distorted signal and volume directly from feedback via the amp. Often such things as I describe are mistaken for progress or even success, as much as anything because it is believed that it should work and something appears to be happening. But this is naive and often misrepresented...people have a right to feel skeptical, I know I got a lot of that before...it was only when people built things and I was able to post actual sound clips that people were convinced. It is notable that those that come and go have made claims but not really backed them up at all with audio or anything. Wouldn't it be great, we all stop making our own drivers, add a pot to a cheap EMG and you're done! Excellent! Lets all pretend that not lifting the ground and hots of nearby unused pickups are unnecessary and use a micro switch in the selector to turn it on. Brilliant! I've repeatedly given the advice that people should do this...honestly they should. It is only when people do these things that they learn. The micro switch idea could work with some clever additional wiring and limiting of selections, but the intention is just to avoid the aesthetic of a toggle switch really, and doesn't even fulfill all those functions as described. Running massive amounts of power into a mismatched coil will produce massive EMI...buy actually doing this it will become apparent and teach what I had to find out by doing exactly that (see the first post here)... Yes, that is the point.....who would have thought it possible to produce such a device (eBow) as a stand alone unit, and so compact? It took a man with the vision and the necessary technical and electronics skills to accomplish this goal. No doubt he had an idea of what he desired to create, then put those skills to use until he found a way to succeed. I feel that it is a shame that he stopped there, because I think that it has simply not reached its full potential. Well...have you read the patent? Have you seen from my research that there were sustainer devices proposed way back in the 1890's. The eBow is elegant, but very simple and does not do all that many people expect. The ebow patent spends most of it on a hex version. As I recall he suggests a masive amount of lead between the drivers and pickups...this is just alchemy...lead is not magnetic and completely impractical and would have no effect. Perhaps a massive piece of steel...but even then I doubt it. But, go ahead and try it...perhaps moog is doing something of that ilk, perhaps Hank will have success with his hex ideas. I wonder whether anyone has tried somehow extending the magnetic field of an e-Bow like device, so as to make it affect all the strings at once? Yes...it's called a sustainer! The fact is that the bigger the coils (pickup and driver) the bigger the EMI effects and as a result you need massive gap between the pickup and driver coils...at least 6 times as much...surprise, surprise...this is about the gap between the bridge pickup and neck driver! You wouldn't be able to move such a device along the strings, it would be impracticable in performance (how would you dampen the strings you don't want driven?) and having the driver above the strings makes the EMI spread worse. Well, with Quantum Mechanics breaking all the rules and laws of Physics as we thought we knew it, perhaps it really depends upon how we look at the problem. Perhaps...but Quantum mechanics does not change the general laws of physics, it looks deeper into it. It only works at the micro scale or on hypothetical alternate dimensions. There are hints of all kinds of things we don't know, QMs is one way of understanding such things. Gravity does not reverse because of these 'revelatory ideas', magnets still have two poles. I think you are thinking too much about this without doing the work that would be pushing you in the right directions. No matter the amount of speculation, this in no way is going to get you closer. You have been considering this project for a very long time and it is time to get some wire and wind some coils, build a circuit and have a go at it. pete Link to comment Share on other sites More sharing options...
psw Posted March 19, 2009 Author Report Share Posted March 19, 2009 Hmmm...double post... Ok...since you asked... What about the rest of the quote? As to my reasons for not proceeding in the more tried and tested paths, for one thing, I have been advised that for an acoustic application the tried and tested approach is not likely to work, because : QUOTE for that application, the best would be a preamp and a piezo-electric p/up that was capable of making the guitar vibrate, as a coil such as those proposed on the forum for an acoustic guitar would be insufficient, because the sounds produced by a sustainer are not the same as those produced by playing with a pick, but more like a violin, too continuous, with no emphasis on the attack produced by a plectrum. In any case, it would also be a question of trying it out as a replacement for a p/up with a microphone preamp, and the LM386 amplifier proposed by the forum, which is sufficient for a thin coil of 8 Ohms. Because the strings on an acoustic are also steel, it will also get them to vibrate, it will be enough just to try and see whether the sound is adequate , and if you like it, one could then add something more complicated with the ACG in order to reduce battery drain. Another approach would be to use the same circuit but substitute a piezo-electric p/up for the driver coil and try it out to see how it works in different positions on the guitar in order to determine where the notes vibrate the most strongly. Now this is grossly unfair use of quotes. Firstly to those reading it that might see it is some kind of gospel or attributable to me or someone else contributing here. By prefacing this unattributed quote with the word "because:" this qualifies that this comes from some kind of informed authority. Secondly it is unfair to the person that you are quoting who can't defend these comments. that is only the continuation of an observation, no more than thinking out loud, I would guess. Yes an ill informed naive ideas...nothing wrong with that...unless it is presented in the way you did and then use it as a reasoning to dismiss the experience and observations because you have this offhand opinion from an unknown source. Now I am answering someone who is through you. It is difficult to hold 5+ years of research and the many people who contributed here to catch out this kind of thing... ... Ok..so lets dissect the quote... for that application, the best would be a preamp and a piezo-electric p/up that was capable of making the guitar vibrate, as a coil such as those proposed on the forum for an acoustic guitar would be insufficient, because the sounds produced by a sustainer are not the same as those produced by playing with a pick, but more like a violin, too continuous, with no emphasis on the attack produced by a plectrum. This just makes no sense at all...this is just weird honestly... ...In any case, it would also be a question of trying it out as a replacement for a p/up with a microphone preamp, and the LM386 amplifier proposed by the forum, which is sufficient for a thin coil of 8 Ohms. Trying what out...a piezo driver? There are sooo many problems with this idea...and yes I explored the area a lot! The piezos don't have the mechanical strength to produce the vibrations required and against the significant tension of strings. However, there are huge mechanical problems to do with momentum and such that cause massive effective phase shifts...but mostly the inability to respond with the speed required. But as always...try it and see...either in the real world or the minds eye. ...Because the strings on an acoustic are also steel, it will also get them to vibrate, it will be enough just to try and see whether the sound is adequate Yes..well except for the conditioning of the signal and fighting the top vibrations that might cause howl at any volume...it could be made to work. In fact, preliminary tests show this to be true in principle. and if you like it, one could then add something more complicated with the ACG in order to reduce battery drain. Well...yes...the idea of using an AGC is also about control and response ass well of course... Another approach would be to use the same circuit but substitute a piezo-electric p/up for the driver coil and try it out to see how it works in different positions on the guitar in order to determine where the notes vibrate the most strongly. Yes...well...this is implying that you can work out the resonant frequency of the top which we all know has an extremely complex vibrational pattern that changes with each note and while the note is sounding. (if you think the nodes of the strings vibration are a concern...consider the complexity of an acoustic guitar's top as far as nodes!) But then, you are presupposing access to piezo crystal arrays that has the kind of potential power and physical capacity to move the top and the enormous pressures of the strings...and to do that with no losses, resonant peaks and troughs, and can miraculously overcome the powers of momentum once the top or strings are moving at thousands of vibrations per second. ... Now...I don't know why the person you quoted may be thinking that...but maybe it was simply "thinking out loud" without the benefit of deeper thought, reflection and experimentation...or maybe he just doesn't realize the issues at hand...or maybe he is just naive. You however, have used this to justify a completely different approach in the face of cohesive argument and informed evidence to the contrary.... As to my reasons for not proceeding in the more tried and tested paths, for one thing, I have been advised that for an acoustic application the tried and tested approach is not likely to work I don't even think that that is what was being said in the quote either.... Because the strings on an acoustic are also steel, it will also get them to vibrate, it will be enough just to try and see whether the sound is adequate See...reinforcing what I have been saying...try it and see! I guess what is missing from the "quote" is the question that the person was responding too...was he answering a question like, is there an alternative way of doing this, would piezos work for an acoustic guitar, etc... pete Link to comment Share on other sites More sharing options...
Hank McSpank Posted March 19, 2009 Report Share Posted March 19, 2009 (edited) zfrittz6's idea was to use a micro switch at one selector position to turn power on to the sustainer circuit when the bridge pickup is selected. Sounds good...however, on any conventional strat or multipickup guitar, the grounds to all the pickups will still be connected and this is not an adequate switching circuit. I'm a little puzzled over that statement ...perhaps you've tested the idea & had problems? In my experience ground is ground.... sure, the unused pickups will stilll have their ground connection 'starred' back to q common ground, but I'm puzzled as to why tsuch a mini switch would be a problem in practise? (ie if you have very good quality guitar cable & excellent star wiring in your guitar, the driver EMF shouldn't be discernible via the unused pickups' ground path. But, go ahead and try it...perhaps moog is doing something of that ilk, perhaps Hank will have success with his hex ideas. Well, I've been in radio silence wrt driver construction here, as I had to go off on a tangent to spec/design/build a hex coil 'automatic feed traversal' system. For this, I had to learn about basic PIC Programing (and for me, that was painful!) & then knock up a circuit to support the PIC (ie PIC -> stepper motor electronics etc). Anyway, my PIC program duly finished I tested it out roughly last night on a breadboard lash up - it seems to works! (ie I can now instruct the PIC .."after 60 turns of the main motor, then reverse the direction of the wire feed traversal helix motor" the idea being to have some form of flexibility & replicatability ...which is obviously important when you need six of them! I now just have to neaten the whole rats nest up & give my coil winder its first dry run (probably Sunday night now). At last, I'll then be ready to start experimenting with hex driver circuits (and hey, here in the UK the clocks go forward this weekend ...meaning it must be nearly warm enough to spend more than 30 minutes in my freezing loft!) Edited March 20, 2009 by Hank McSpank Link to comment Share on other sites More sharing options...
psw Posted March 20, 2009 Author Report Share Posted March 20, 2009 I'm a little puzzled over that statement ...perhaps you've tested the idea & had problems? Very few people seem to make multipickup sustainer guitars it would seem, so it is not important nor the problems that can and will occur be tackled. The pickups coil will act like an antenna and it is not just enough to de-select the pickups with the sustainer on...the EMI noise (fizz, or worse) will get into the ground through magnetic coupling. Lifting the ground and the hots are necessary. The most efficient way of doing this is to take out the entire selector and replace it with the bridge pickup direct to the controls. This means at least a dpdt to affect this function. You will also need a on off switch for the power...so a minimum of 3pdt...but often you may need to treat the middle and neck separately...and then, you will need some kind of switch to connect the bridge pickup regardless of the selection...so a 4pdt typically. Now, you could do that with a proper 4p5t super switch as one of the selections...but it is not enough to simply turn the thing on. It is this that convinced me to forgo experimentation in a remote "sustain box" because in reality the rewiring is so extensive, it may as well go inside the guitar. My coircuits have 10 wires coming out of them...you don't want to try and get a ribbon cable like that into the guitar from the outside. Instead I switched to what most people thought was a better idea and look anyway (even after seeing the realizations) by making the thing smaller and working on installation, compact drivers and other issues...as illustrated in the tele. ... As always...feel free to find another solution...but it pays not to make assumptions about these things till you try it. I discovered this when i did the sustainer strat. I now realize that a lot of the earlier work, most of my hex stuff may have failed as a result of not knowing this. It doesn't come up often because people often completely replace the neck pickup with a driver. I have particular problems also because I will often combine the neck pickup and the driver on the same magnets...but the middle pickup is also a problem, or if the driver is just next to a pickup. maybe i am failing to explain things well...i'm struggling...but consider that the ground is also connected to the driver coil as well as anything else connected to it. There is a transformer effect between nearby coils that creates a voltage, some of this will leak through. ... Well, I've been in radio silence wrt driver construction here, as I had to go off on a tangent to spec/design/build a hex coil 'automatic feed traversal' system. You sound like me...i hope you have considered that they might not work? I was up against a similar thing with my ultra thin coils...build a machine and test epoxies to make it in order to make it, to see if it works...hahaha. Fortunately for both al and me, the apparatus is fairly simple (my 1mm coreless coils were more difficult)..no pic technology...but I was working in that direction for a bit. A lot of my hex things were ridiculously difficult to make...some didn't work at all...none worked better than the ones I make now by conventional means. And, all the installation and other issues will still exist regardless... That is why I might have sounded a little too negative, but remember I dedicated an entire year on the things making at least one a week! There are a lot of issues yet to come...a successful hex driver is only partly there. Similar with Al's drivers...great stuff and working...but at least a way of installing it is pretty clear. Anyway...one step at a time...maybe when you get there you will find some alternative answers...but I doubt it will be "easy" or straight forward! pete Link to comment Share on other sites More sharing options...
Hank McSpank Posted March 20, 2009 Report Share Posted March 20, 2009 (edited) The pickups coil will act like an antenna and it is not just enough to de-select the pickups with the sustainer on...the EMI noise (fizz, or worse) will get into the ground through magnetic coupling. Lifting the ground and the hots are necessary. But you've not given a technical reason how ground can be anything else but ground? With your antenna analogy...it's the 'hot wire' that picks up any radiated signal ...not the ground (the ground is merely a reference). Like I say, if you have good grounding internally throughout the guitar & a good quality cable to the guitar...there's no way that ground can be anything but ground, so lifting the hot from the deselected pickups ought to be sufficient. (is it possible that when you tried some EMI was still being picked up by the active pickup & this was assumed that the deselected pickups were interfering with the setup?) i hope you have considered that they might not work? I was up against a similar thing with my ultra thin coils...build a machine and test epoxies to make it in order to make it, to see if it works...hahaha. Fortunately for both al and me, the apparatus is fairly simple (my 1mm coreless coils were more difficult)..no pic technology...but I was working in that direction for a bit. Of course, I've certainly considered that they might not work...but I don't consider the time/effort I've put into my coil winder as wasted. I now know how to write programs for PICs (& I've a whole load of other niggles needing a solution around the house that could easily be solved use a PIC!) A lot of my hex things were ridiculously difficult to make...some didn't work at all...none worked better than the ones I make now by conventional means. And, all the installation and other issues will still exist regardless... In between all of this, I'm about a 3rd of a way into a DIY CNC machine build (no hacksaws & CD cases this end!) - this bit of kit will be essential for making a decent bobbin (my 'mother' bobbin needs to hold six bobbin-ettes). I've always hankered after a CNC machine (every shed should have one!) so this has made me get off my backside & build one. The 'X' plane is finished...two more planes to go! (to get an idea, what a boon this will be from about 4m33secs in ...imagine that thing cutting out a bobbin from acrylic!) That is why I might have sounded a little too negative, but remember I dedicated an entire year on the things making at least one a week! There are a lot of issues yet to come...a successful hex driver is only partly there. Yes, the negativity does permetate through a bit! We're all coming at this with different skillsets & knowledgebases. I realise this is going to be a tough nut to crack. This is another reason why I've gone the way of an automatic pickup winder (& diy CNC) ie once finished, it'll piece of p1ss to knock up a new hex driver design. Since I'll be able to crank out drivers quickly/bobbins quickly, it's then just the law of averages wrt getting the right driver design! Edited March 20, 2009 by Hank McSpank Link to comment Share on other sites More sharing options...
psw Posted March 20, 2009 Author Report Share Posted March 20, 2009 (edited) I'm sorry...what can I say... Although I have very little and no formal electronics training...I have had years of first hand experience with this and helping others do the same and in every incidence the effects are true. Anyone who attempts this should test their drivers and circuits before installation by holding the driver above the fretboard. Even in this test mode with the bridge pickup selected only (but the grounds of other pickups connected) you will get distortion and noise and often oscillation if you venture towards these pickups too close, even though this will be the intended mounting place. Yet, by bypassing both ends of these coils and mounting the pickup, or in a single pickup guitar...such symptoms do not exist. There was some successful and interesting results by running a driver and a neck pickup in parallel...however, the switching chores are similar if not more complex (if there is a third pickup involved). So...perhaps I can't explain it...but it is in fact true...verified over and over in many installations and experiments, and in the efforts of others (though admittedly, those who attempt multipickup installations are rare) over a number of years now. I do hope, and have hoped that others would follow to find a work around or explain better these effects..but alas, although many knowledgeable people have come and gone over the years, the exploration of these things has been somewhat neglected and it has been left to me to describe the phenomena and more besides as best I can. But you've not given a technical reason how ground can be anything else but ground though? With your antenna analogy...it's the 'hot wire' that picks up any radiated signal ...not the ground (the ground is merely a reference). Like I say, if you have good grounding internally throughout the guitar & a good quality cable to the guitar...there's no way that ground can be anything but ground so lifting the hot from the deselected pickups ought to be sufficient. (is it possible that when you tried some EMI was still being picked up by the active pickup & this was assumed that the deselected pickups were interfering with the setup?) so...that addresses the first sentence...kind of. I am not sure what you mean about the ground being anything but a ground...the ground is the inverse of the hot, so they are two sides of the same coin in many ways in relation to this...or am i wrong thinking (its very late). As for guitar cables and shielding...this will only stop RFI interference really, not the kinds of EMI coming out of a driver at close quarters. Even the driver wires (an extention of the coils) can cause troubles...look at the sustainiac installation instructions....or the way I fed the leads through the trem cavity on the original sustainer strat to help with this effect. Let me try and cobble together a hypothesis and some things to consider. You say the ground is purely a reference...but I am not entirely sure...but maybe in this you are pointing towards a solution. In a typical circuit like the LM386...one end of the driver is connected to ground. With a hot lift as in a selector, the grounds are all connected throughout the guitar. So...there is a swing potential perhaps as the drivers AC signal is passed through these coils. As the hot is lifted, there can be no circuit, but all coils have capacitance and perhaps the noise is the charging and discharging of this. Although the hot's lifted physically...a close driver coil is creating a transformer effect in these nearby coils and some signals are swinging the ground reference, creating noise and current in the coils. Also consider the massive difference in impedance between a pickup and a driver...the sensitivity of the pickups are capable of greatly amplifying coupled magnetic signals... but...you can probably tell i am struggling here. What can I say...this is what I found time and again, no matter what I do...why, perhaps you could come up with an idea in technical terms. We are talking about getting a guitar and putting only a driver and bridge pickup in there for instance and getting that to work pretty well. Then adding back in successively one or more pickups with the hot lifted, with the coils shorted, with both hot and ground lifted...hb pickups, stacked pickups, SC pickups, dual coil drivers...stacked driver/pickups...stand alone drivers... Time and again I have tried to get people to focus or help in this final step...but to no avail. Few have seen fit to make multipickup installations and those that have had had similar experiences. It is one of the frustrations that people seem so engrossed in finding a different way, that they have lost sight of some of the practicalities or made assumptions. But really it is just that I'd like to get some help in some of these issues myself or the words to explain it. Remember, when I was doing a lot of this work, there was no one else doing it or hanging about writing long posts of technical information really. You might take some heart in the fact that it was not till later that I was able to discover and address these issues and so many of my hex driver ideas may well have worked had I completely removed these other pickups from the equation...but I did not anticipate it. Perhaps I should have, it would appear the commercial units suffer in similar ways and use complex electronic switching to get around it. I've certainly considered this might not work...but I don't consider the effort I've put into the coil winder as wasted. No it isn't...there is lots to discover. auto transversing winders have always fascinated but have always eluded me (not for drivers, but for pickups). I am sure there are heaps of PIC projects that will help. A CNC would be very cool...even a small one for bobbin making and such. Just thinking and inventing is a reward unto itself. I did get successful hex drivers working, I was able to substantially miniaturize them in the process. It would be great to see something come of it...even if I now have my doubts (separation and magnetic coupling between drivers being chief among them). If not drivers...perhaps hex pickups from the same machine...there is lots of potential there as well. Yes, the negativity does permetate through a bit! Yes...well all I can do is acknowledge it really. There are a lot of good reasons for my dour attitude at present. But I am trying hard not to just knock things...I really do care you know. I am just trying to warn people of the reefs they may encounter or reveal some fallacies that seem to exist from time to time. This thread is the appropriate place for exploring and reporting on these ideas, but I do get feedback from others who feel that it is a none working project still looking for answers when they try and approach this. It is not, a working DIY sustainer design has been in existence now for many years. It requires no machines nor advanced circuit building really...if you could make an effects box and rewire a guitar, this thing is not that hard. People have made the thing without even joining PG or my help...they occasionally send an email to thank me...so it can't be that hard, or there are a lot of geniuses out there in disguise. I am probably a bit slow on the uptake these days...but I am still at a loss at what you and david and others over the years are trying to achieve. I know that you have given some reasons...and perhaps there doesn't need to be a reason...obviously I thought enough about the hex concept to pursue it. To your credit and as you say, the law of averages is with you, you are getting down to the processes of making the thing and can see a road ahead as well as travelling some way along it. I'm still not entirely sure why you don't just make a test coil of a known design and see how that goes, if only for a reference. I probably made 40 hex designs, most of them unique before I abandoned that strategy. Al S went straight in to build upon that work with success and to me that seems more exiting at the moment. I'd still like to see it installed and how he addresses these problems...perhaps it would be better if someone else proves or disproves my findings or works out a better solution. pete reading that appalling post...antenna is the wrong word. I think the technical thing is that the magnetic coupling is generating a current in nearby coils that is held in it's capacitance. as the AC signals relax some signal or noise of this capacitance is released to the ground. Even that doesn't make sense....but perhaps that better explains my thinking in shorter form before sleep. The phenomena however I fumble to explain it is very real! Edited March 20, 2009 by psw Link to comment Share on other sites More sharing options...
Hank McSpank Posted March 20, 2009 Report Share Posted March 20, 2009 (edited) Let me try and cobble together a hypothesis and some things to consider. You say the ground is purely a reference...but I am not entirely sure...but maybe in this you are pointing towards a solution. In a typical circuit like the LM386...one end of the driver is connected to ground. With a hot lift as in a selector, the grounds are all connected throughout the guitar. So...there is a swing potential perhaps as the drivers AC signal is passed through these coils. No...the ground should stay clean...no matter what. As the hot is lifted, there can be no circuit, but all coils have capacitance and perhaps the noise is the charging and discharging of this. Although the hot's lifted physically...a close driver coil is creating a transformer effect in these nearby coils and some signals are swinging the ground reference, creating noise and current in the coils. Also consider the massive difference in impedance between a pickup and a driver...the sensitivity of the pickups are capable of greatly amplifying coupled magnetic signals... but...you can probably tell i am struggling here. What can I say...this is what I found time and again, no matter what I do...why, perhaps you could come up with an idea in technical terms. As much as you;'re struggling to explain, I'm struggling to see how any EMI can interfere with the guitar's ground path. A good ground should never deflect from what it is ....a reference point which isn't deviated from. We are talking about getting a guitar and putting only a driver and bridge pickup in there for instance and getting that to work pretty well. Then adding back in successively one or more pickups with the hot lifted, with the coils shorted, with both hot and ground lifted...hb pickups, stacked pickups, SC pickups, dual coil drivers...stacked driver/pickups...stand alone drivers... That reads like you're overcomplicating/fogging the issue Did you try out zfrittz6 idea to see how it performed? Like I say, I can't think of any reason why it wouldn't work. I mentioned earlier, that anyone adding a sustainer to their guitar should be able to keep their chosen original pickups. His idea is certainly elegant in its simplicity...& I'll be investigating this path (that'll be the final stages though!). Time and again I have tried to get people to focus or help in this final step...but to no avail. Few have seen fit to make multipickup installations and those that have had had similar experiences. It is one of the frustrations that people seem so engrossed in finding a different way, that they have lost sight of some of the practicalities or made assumptions. But really it is just that I'd like to get some help in some of these issues myself or the words to explain it. Remember, when I was doing a lot of this work, there was no one else doing it or hanging about writing long posts of technical information really. before I even lift a soldering iron, I want to ponder the issues time & time again...of course, there's a danger you can get yourself into a recurring loop, but it's much quicker to think through (again & again) designs, to foresee & address the problems in 'grey matter', than to have to react to them after just putting your Nike T Shirt on and "Just Do it" (because 'making stuff' is *real* time sump) I am probably a bit slow on the uptake these days...but I am still at a loss at what you and david and others over the years are trying to achieve. I know that you have given some reasons...and perhaps there doesn't need to be a reason...obviously I thought enough about the hex concept to pursue it. To your credit and as you say, the law of averages is with you, you are getting down to the processes of making the thing and can see a road ahead as well as travelling some way along it. I'm still not entirely sure why you don't just make a test coil of a known design and see how that goes, if only for a reference. I can't speak for David, but there's little point in me making a test coil of 'known design' & then trying to use it for a totally different setup (& I'm not sure there is a 'known design' for a one string driver?). That's a bit like saying "why not build a rowing boat - plenty of known designs out there"...but what if the designs out there aren't suitable for my journey? This thread has obviously evolved into the 'mother thread' for those who want a cheap (?!!), fun project towards building a mono sustainer (& as you've suggested, why reinvent the wheel if that's all a visiting dabbler seeks) - but surely the mother thread still has the capacity to dock mono sustainer 'offshoots'....or do you want to keep the thread 'pure' to those following your thin driver? PS As an aside, I recently bought an awful 'catalogue Strat copy' off Ebay (for me to hack the hell out of)...I was quite shocked at how much even awful Strat copy variants are getting bid up to on Ebay - so much for there being a credit crunch when a chipped, awful strat copy sells for £25+ postage! Edited March 20, 2009 by Hank McSpank Link to comment Share on other sites More sharing options...
col Posted March 20, 2009 Report Share Posted March 20, 2009 No...the ground should stay clean...no matter what. Here's a quick attempt at a possible explanation of what Pete is talking about. First, go here and read about why star grounds are used in valve amps. Now consider Petes 'piggy-back' driver design. A driver coil with relatively few turns in very close proximity to a pickup coil with thousands of turns. The two coils act as a transformer, the current in the driver coil inducing a current in the pickup coil (the pickup coil will develop a relatively high voltage). With the pickup coil connected only at the ground, any current induced will flow through the ground connection. Surely it's possible that, depending on the driver circuit, ground layout, quality of components and construction etc. this could add noise and potentially cause parasitic feedback? Think about the river analogy on that web page... cheers Col Link to comment Share on other sites More sharing options...
Hank McSpank Posted March 20, 2009 Report Share Posted March 20, 2009 (edited) No...the ground should stay clean...no matter what. Here's a quick attempt at a possible explanation of what Pete is talking about. First, go here and read about why star grounds are used in valve amps. Now consider Petes 'piggy-back' driver design. A driver coil with relatively few turns in very close proximity to a pickup coil with thousands of turns. The two coils act as a transformer, the current in the driver coil inducing a current in the pickup coil (the pickup coil will develop a relatively high voltage). With the pickup coil connected only at the ground, any current induced will flow through the ground connection. Surely it's possible that, depending on the driver circuit, ground layout, quality of components and construction etc. this could add noise and potentially cause parasitic feedback? Think about the river analogy on that web page... cheers Col Those are my bolds - it seems we're trying to conceptualize why a simple switching solution won't work! (& I thought we're all chasing simplicity?) I think Pete needs to clarify (or anybody come to that) ...has the switching idea that discussing, actually been tried out under test conditions? Because Pete pretty much disregarded this simple concept idea a couple of posts ago. (and zfrittz6 said it worked) The reason I'm labouring the point, is because it's an important issue. When choosing a sustaining device, a electric guitarist (or come to that a designer), has few options... 1. Remove the neck pickup (not good - you lose the pickup that was meant to be on the guitar!) 2. Buy a sustainer combined/integrated with the manafacturer's pickup (again not that great an option as your getting a pickup 'bundled' ...ie it's not your first choice) 3. Keep the Guitar's original pickups, then integrate a small sustainer driver & get 'creative' with the placement and/or switching! 'Creative' here being - simply disabling the sustainer when any pickup other than the bridge pickup is selected. Beautiful in its simplicity? Of course the compromise here is that you can only sustain notes sourced from the bridge pickup...but in my opinion, for most guitarists, this would likely be the lesser of all evils. We can all come up with plausible "what ifs", "mights" & "perhaps" theories (but presently, I'm not swaying - ground potential is ground potential :-) - & unless someone has tried this out under decent test conditions (proper earthing layout within the guitar, decent guitar cable etc), it would seem quite wrong to dismiss one of the few options open wrt keeping the original pickups on a sustainer bestowed guitar. Edited March 20, 2009 by Hank McSpank Link to comment Share on other sites More sharing options...
psw Posted March 20, 2009 Author Report Share Posted March 20, 2009 Thanks Col.... No...the ground should stay clean...no matter what. Here's a quick attempt at a possible explanation of what Pete is talking about. First, go here and read about why star grounds are used in valve amps. Now consider Petes 'piggy-back' driver design. A driver coil with relatively few turns in very close proximity to a pickup coil with thousands of turns. The two coils act as a transformer, the current in the driver coil inducing a current in the pickup coil (the pickup coil will develop a relatively high voltage). With the pickup coil connected only at the ground, any current induced will flow through the ground connection. Surely it's possible that, depending on the driver circuit, ground layout, quality of components and construction etc. this could add noise and potentially cause parasitic feedback? Think about the river analogy on that web page... cheers Col Basically this "transformer effect" is the root of the "problem" and others like "fizz" and "squeal" of course. Putting the coils on top of one another makes an obvious transformer, but the effect is still there is if is just "nearby" as in my tele and can be heard even in the middle pickup of a strat. As a further clue, the effect is markedly worse when the phase (harmonic switch) is reversed on one of the coils. That reads like you're overcomplicating/fogging the issue Did you try out zfrittz6 idea to see how it performed? I'm surprised at that...to me it suggests I tried every combination that I could come up with in a systematic way...not a small task. I've even confessed that though assuming that there should be no problem, I ignored that it was there and invalidating a lot of previous work that may well have "failed" because of these effects. zfrittz6 idea was to use a switch to turn it on when the bridge pickup is selected. So...to simulate that, all you need do is put the selector to the bridge and connect the power...so yes, of course that was done time and time again. Look at that "sustain box" idea...isn't that what was done there? I have no interest in fogging the idea or making it overcomplicated...quite the contrary. Obviously I have put perhaps excessive thought into this, it is no a "just do it" mentality...surely this thread shows that. However, you can't expect things to be known if you don't experience the evidence and address it in the real world. Correction, you can if you can draw on the experience of others...which is all that I am trying to do here. Look at my tele's wiring... Do you honestly think that I would put a 4pdt switch in there with all that complication if I didn't have to? And we are talking a very quiet guitar, SCn neck HB and bridge HB and a driver quite separate, not stacked as in some designs. That's a bit like saying "why not build a rowing boat - plenty of known designs out there"...but what if the designs out there aren't suitable for my journey? Because...before you build an ocean liner, it might be prudent to try and understand how a successful design works (as I did by reading all the patents, making single coil drivers, etc) and some of the basic common factors of things like displacement and the like, motion through the sea...the navigational obstacles and shallow waters it might be necessary for your liner to get through before it even does get out to sea. Perhaps not a rowing boat, but I would definitely make a scale model and float it in the tub before embarking on a years construction or more of a major project. My suggestion to try something basic like a coil to a circuit is just that...look at Als recent coils, not really that much of an investment to observe things that have had tens of thousands of words spent on them, and behind them countless hours of thought and real world experimentation. ... OK...here for the first time is one of many hex drivers. I applaud your attempt at this, but remember, I'm the guy who spent a fairly intensive year on these things...my designs don't display a just do it approach with all due respect...and behind many or most of these things is an investment in jigs or machines to build the things... On this you will see several features (by the way there are no magnets at this stage)... There are six individual drivers, an LED and a micro switch. One of the aims that I have so far not achieved was a momentary control...so that sustain could be added at will to individual notes and in this design it was built into the side of the driver itself. I can assure you that it was not through lack of thought, careful consideration and planning that I embarked on those endeavors. However, before this, I did test individual driver elements of the same design to ensure they worked. Similarly with the thin driver/pickup...I didn't "just do it"...I built a thin driver and tested it and found it to work...I then thought that it might be possible to combine the two and exactly duplicated it. I think it is important to note that the thin coil design did not come as a result of wanting to combine the pickup and driver but because it was the most effective design that I was able to come up with out of many. I mentioned earlier, that anyone adding a sustainer to their guitar should be able to keep their chosen original pickups. Yes...absolutely...but this was high on the list back in the page 30's and more besides. Unfortunately not all things were possible. For instance, you should be able to do this with no modification at all to the guitar...that would be nice (hence the sustain box ideas), or that the device should work with any pickup selection, not just the bridge pickup...I want that, or I could just touch the side of the driver or pickup ring at a hidden switch or touch pad and evoke singing sustainy feedback at will to any note at all...yeah! But, that is not likely to happen on a conventional guitar. I too built piezo bridges to run hex designs you know...this is a far more complicated proposition than most...and six individual ones at that. Hardly a likely scenario for just "anyone"! While we can't have everything perhaps...there is a lot that can be had. Many of the things on the "wish list" may well be possible in some imagined instrument for the purpose. One of the most obvious ones that would achieve most of this would be a variaxe where different pickups and sounds are modeled, where you really could have a micro switch by the bridge and just lean on that to evoke feedback at will. But you don't even need to go that far...a single pickup guitar like cols could have similar features and only miss out on not having multiple pickups, that sounds like an excellent instrument too! This thread has obviously evolved into the 'mother thread' for those who want a cheap (?!!), fun project towards building a mono sustainer (& as you've suggested, why reinvent the wheel if that's all a visiting dabbler seeks) - but surely the mother thread still has the capacity to dock mono sustainer 'offshoots'....or do you want to keep the thread 'pure' to those following your thin driver? No...not at all. But I would be doing people a disservice if I were not to point out that there were icebergs ahead, would I not? You also do the thin coil or other designs a disservice by suggesting that the thing is "mono"...you don't need to go down the hex road to sustain more than one note at a time and some of your assumptions are at this stage naive I am thinking. I have yet to hear how you are going to deal with the drivers interacting with one another to combine the hex thing into a "mono" driver anyway...but obviously I was convinced for a long time and you may well come up with an answer that meets your needs...but there does seem to be a lot of assumptions that have been overlooked that I shared as well. So...no, I am not just knocking ideas or innovation, nor is the "thin design" pure...it has stood the test of time and been further refined with success (thanks Al s) and does have a status as a benchmark for want of anyone coming up with a better idea to fit that role. I am just pointing out that, no matter if you build a rowing boat or an ocean liner...the perils of the sea remain the same! pete Link to comment Share on other sites More sharing options...
col Posted March 20, 2009 Report Share Posted March 20, 2009 No...the ground should stay clean...no matter what. Here's a quick attempt at a possible explanation of what Pete is talking about. First, go here and read about why star grounds are used in valve amps. Now consider Petes 'piggy-back' driver design. A driver coil with relatively few turns in very close proximity to a pickup coil with thousands of turns. The two coils act as a transformer, the current in the driver coil inducing a current in the pickup coil (the pickup coil will develop a relatively high voltage). With the pickup coil connected only at the ground, any current induced will flow through the ground connection. Surely it's possible that, depending on the driver circuit, ground layout, quality of components and construction etc. this could add noise and potentially cause parasitic feedback? Think about the river analogy on that web page... cheers Col Those are my bolds - it seems we're trying to come up with theories why a simple switching solution won't work! (& I thought we all sought simplicity?) Yes we are - the simple solutions that have been tried don't work, so it helps to think about why that might be. I think Pete needs to clarify (or anybody come to that) ...has the switching idea that discussing, actually been tried out under test conditions? Because on the face of it, Pete has pretty much disregarded this simple micro switch idea a couple of posts ago. well, that depends what you mean by test conditions - I don't think Pete was using a laboratory standard rig with scopes and meters, but he built it and it didn't work. I trust that he built it 'correctly' ie. all wiring was checked multiple times for errors, bad workmanship etc. We can all come up with plausible "what ifs", "mights" & "perhaps" theories - & presently, I'm not swaying - ground potential is ground potential :-) - & unless someone has tried this out under decent test conditions (proper earthing layout within the guitar, decent guitar cable etc), it would seem quite wrong to write off one of the few options available wrt keeping the original pickups on a sustainer bestowed guitar. ok - so ground potential is ground potential, a perfect 0 in a textbook. But in reality, thats not always the case, wires are wires and all have resistance capacitance and inductance. Ground potentials can drift, different parts of a circuit can have slightly different localized ground potentials, unwanted parasitic currents can flow. Personally, I've not tested the circuits Pete was using, but hey, if you think more work needs to be done developing that side of things, get to it - then tell us we were all wrong (or right) one way or the other, that's how things get done. FWIW, Pete spent loads of time (and posts) explaining the weird effects he was getting with his switching setup. The only thing that cured the feedback and oscillations was disconnecting both of the pickup connections. I'm suggesting a possible reason for the symptoms he described - I haven't had those problems because I'm not trying to piggy-back a pickup. The thread search facility works pretty well, so you should be able to find some relevant posts from way back when, with a little effort. Link to comment Share on other sites More sharing options...
psw Posted March 20, 2009 Author Report Share Posted March 20, 2009 Those are my bolds - it seems we're trying to come up with theories why a simple switching solution won't work! (& I thought we're all chasing simplicity?) Hmmm....I thought you were chasing the ultimate in complexity for improved polyphonic performance by using hex pickups and drivers !?!?!?! I think Pete needs to clarify (or anybody come to that) ...has the switching idea that discussing, actually been tried out under test conditions? Because Pete has pretty much disregarded this simple concept idea a couple of posts ago. (and zfrittz6 said it worked) YES I have...and more besides. I thought that my suggesting that I used a real guitar, all combinations of driver and pickup types that I had done that! The reason I'm labouring the point, is because it an important point. When choosing a sutainer, a guitarist (or come to that a designer), has only a few options... 1. Remove the neck pickup (not good - you lose the pickup that was meant to be on the guitar!) 2. Buy a sustainer combined/integrated with the manafacturer's pickup (again not great as your getting a pickup bundled ...ie not your first choice) 3. Keep the Guitar's original pickups, then integrate a small sustainer driver, getting 'creative' with the switching! No...I think there are more options than that...I'm not sure if the tele fits into three...but no mod to guitar or pickups and similar things have been done on other guitars with different pickups like strats. I have conceptualized a driver into a modified pickup ring for instance and numerous other schemes throughout this thread and done the work to see how this could be made possible. 'Creative' for eaxmple could be what we're debating here - simply disable the sustainer when any pickup other than the bridge pickup is selected. Beautiful in its simplicity. Of course the compromise here is that you can only sustain notes sourced from the bridge pickup...but in my opinion, for most guitarists, this would likely be the lesser of all evils. Hmmm...well, you can only sustain notes with the bridge pickup anyway. Yes...beautiful in it's simplicity and naivety. You can do this though by replacing the selector with a super switch, you could even incorporate the harmonic function in there too. Look at that hex design of mine above...beautiful but ultimately naive. How about this one... Hex design, ultra miniture...and it worked! Can you see how such a device could be incorporated into a pickup ring or stand alone as illustrated here being tested? We can all come up with plausible "what ifs", "mights" & "perhaps" theories - & presently, I'm not swaying - ground potential is ground potential :-) - & unless someone has tried this out under decent test conditions (proper earthing layout within the guitar, decent guitar cable etc), it would seem quite wrong to write off one of the few options available wrt keeping the original pickups on a sustainer bestowed guitar. I am not talking about theories and mights or perhaps...these effects are real, simple switching has not shown to work and huge swaths of this thread has been given over to it. There is nothing in zfrittz6's unqualified, untested and never built proposition that addressed the problems that were evident at the time and he disappeared soon after as quickly as he arrived. He had interesting ideas, but did they ultimately work. Nothing about this switching or mine precludes a choice of pickups (look at my tele, any pickups could have been used, I didn't even need to route out for the driver!) all it does is hide the switching. My uber-switching things was an attempt to do a similar thing (although the super switch could have handled it on it's own) but without the naivity of the idea that all you have to do is connect the power. It was this kind of thing that made much of zfrittz6's grand claims suspect (that along with circuit drawings that didn't work as I recall, amongst other things)...we never saw his drivers in a guitar, we never heard them, the circuits offered never worked or were corrected and the switching was never built. There have been many things on this thread that need to be taken with a grain of salt. David brought up another recently...the old EMG select makes a driver from a preamp and a pot...yes i did try this kind of thing, no it doesn't work, yes we know why it shouldn't work...no we saw no evidence that it might. At least spazzyone submitted a video of his experiments that demonstrated what he was getting out of it. I am not righting off zfrittz6 ideas out of some kind of jealousy that I didn't think of it or that I want it to be complicated...I am pointing out that this project is more complicated than it might at first seem. Blind faith that it isn't has caused countless people to fail. I'm sorry if it sounds offensive, or defensive...but really...I have done the work, spent the time and money and sacrificed a huge amount of time and I am not in the business of trying to make things overcomplicated for the sake of it! pete ps...thanks col Link to comment Share on other sites More sharing options...
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