psw Posted October 1, 2008 Author Report Share Posted October 1, 2008 No, no...it is not rude! The above is a drawing of the sustainer in the blueteleful telecaster...there is some more discussion at this thread Warmstrat proposed project Now...to explain this a little more for you and anyone else interested... The main switch there has 12 connections...the middle 4 connect to the top or the bottom depending on the switch postion...the upper bank is normal guitar with the pickups going to the selector. With the middle bank connected to the lower 4 connections the sustainer is on...from left to right... The first two connects the middle pickup to nothing...note that unlike a selector it lifts both the + & - ends of the pickup coil so it is completely removed. With a more complex guitar, you would need to perhaps lift the entire selector and exchange it with the bridge pickup, thereby removing all the pickups but this can be tricky The third set connects the -ve power of the battery to the guitar's ground and in doing so the circuit ground, so turning the circuit on (orange -ve signal input) The last set connects the bridge hot directly to the volume control... When the switch is turned off, the guitar returns to whatever the selector is set to... ... Notice that the circuit is my "fireDrive" design...the 1K drive control is unique to this circuit, a F/R often uses a 10K control...depends on the circuit. Also shown is the harmonic switch...a simple phase control switch but being on the driver wires it does not effect the guitar when the sustainer is off. ... There are other ways and variations, this is what worked with the bluetelecaster guitar however. ... It is important to consider these things...but also important to build a circuit and driver and test your work on a guitar before thinking about installing it. I know it looks and is easy but a lot of people have failed for various reasons and designing a guitar around it before you have been able to successfully build and have the thing working in testing is asking for trouble. This design is very simple in principle but as you can see from the size of this thread, the subtleties of the project are frequently underestimated. The driver is often underestimated...the quality of the coil, specifications and design are fairly crucial to success and often you may need to make a test coil to learn from the initial mistakes. ... Hopefully, I will be able to offer a few limited premade circuits in the near future but as yet I don't know the cost as my circuit uses a few tricky components and is of course hand made... I am heading for a personal financial crunch which may force me to consider these things, possibly even making some coils...but as always...the success is going to be in the hands of the person actually installing the thing and planning the project and there are some situations where the device is just not going to be suitable... ... So...any more questions? pete Link to comment Share on other sites More sharing options...
megadog Posted October 2, 2008 Report Share Posted October 2, 2008 (edited) Ok cool that helps so much. So here is an example of the circuit wiring for the setup i want to use from stewmac. Stewmac Wiring diagram Or the alternative 2 vol and 2 tone option...Stewmac wiring diagram 2 I'm still stumped in terms of exact wiring and I know I'm being repetitive but could you show me the setup in relation to one of these circuits it doesn't matter which one. Just understand better with visuals. Sound a bit kiddy but it's just how I am. Edited October 2, 2008 by megadog Link to comment Share on other sites More sharing options...
psw Posted October 2, 2008 Author Report Share Posted October 2, 2008 Maybe...diagrams take more time....you wnat to be sure you can actually get the device to work first...also, this is a DIY thing, not a pete works it all out for you! Anyway...the 2+2 control layout is probably ovekill if you add the sustain control as well plus a pair of switches for the sustainer...I am not even sure that that would be possible to do... As for the master volume and tone...it is exactly as per the above diagram...two pickups, neck is switched out, bridge connected... I'd like to here more about the circuit you are proposing and how you intend to make, test and install the driver. It is important that you have a very good understanding of what you are getting into and able to work out solutions...I can help, but not do it for you...no offence... pete Link to comment Share on other sites More sharing options...
megadog Posted October 2, 2008 Report Share Posted October 2, 2008 Thank for that. I knew the second circuit was way to complex to do this too and i fully accept your point about the DIY thing. It's just i tried to combine the two circuits and i can't get it. This is a really idiotic question but with the multiple connection points on the 4pdt switch do i need to divide the wires from the pickups? Please note I am a practical guy not the like the electronic whizzes here. I really need some help. I feel like such an idiot asking these questions. Anyway thanks for helping so far its most appreciated. Link to comment Share on other sites More sharing options...
psw Posted October 2, 2008 Author Report Share Posted October 2, 2008 I am not sure about the "dividing wires" thing... I am sorry to sound a little negative...but while working out if it is possible to install this device is important and understanding the principle and what is required also necessary for success...very many people have had difficulty with this project which many would consider "advanced" (although in many ways it is quite simple)... It is very important, and I still do it with every one...to assume nothing and test these things (drivers and circuits) that they are working successfully with a real guitar by holding the driver over the strings above the neck before you get bogged down in the switching and installation part of the project. Perhaps some others could speak to the "problems" they have encountered... There have been many people who have given up despite any amount of help while others have had some success but struggled to make it better. Many though have succeeded with very little experience on the first go. For me it was a long evolutionary process for which I hope to save others... Perhaps you need to take stock of your resources and skills and materials...you will need a reasonable soldering iron and proficiency in using it, a multimeter...and a working guitar to test the thing on. You will also need the ability to fabricate a driver and some ingenuity in making the bobbin and coil of the driver or adapting things to your needs... Maybe we should talk more to your project aspirations...I don't think the 4 knob thing is going to be easy or practical as I said...I do know a 2 knob works. Now, the first stage is to build a circuit and test that this works as an amplifier with a small speaker with a guitar plugged into it and it is a design that will not load the pickup signal. The next stage is to build a driver and test this with the circuit on a real guitar...if you get past those to stages, working out exactly how to tun the thing on will come...some compromises may be required... So...maybe others could add a little light to my shade and confirm my suggestions or make some of their own... pete Link to comment Share on other sites More sharing options...
dibsmjf Posted October 2, 2008 Report Share Posted October 2, 2008 Hello, thought I'd add some of my experiences with this project so far... I originally wanted to add a sustainer to my main guitar, which is a H-S-H and thus a bit more complicated than Pete's Tele. To add to Pete's list of requirements, you need not only a working guitar, but also a guitar which you don't mind taking a bit of abuse and probably a few modifications. My Ibanez is my pride and joy, and so no work gets done on it without soft padding on the desk, masking the paintwork off and very careful soldering. If you're in a similar situation, this isn't the best situation for experimentation, as is required with this project. As a result I'm using a recently donated Epiphone SG, which I don't mind knocking lumps out of, dropping blobs of solder on and generally abusing. Continuing with the SG, when I got it all the electrics were basically shot, so new jack, pots, wiring and switch were needed, to keep things simple I decided to change from the standard SG two volume and two tone setup to a master volume and tone. This not only simplifies the wiring somewhat, it also frees up two control holes, which saves drilling all over the shop. A major part of the sustainer setup is the harmonic mode switch, essentially swapping the phase of the driver coil to get harmonic instead of fundamental sustain. Typically this has been done between the sustainer amp and the driver, but an equally valid way of doing it is between the bridge pickup and the switches. This has an added bonus, in that when the sustainer is off you have the bridge and neck pickups out of phase with each other. I know Pete is always banging on about keeping it simple to begin with, this switching would be part of the simple sustainer anyway, it's just a different place for it which opens up another non-sustainer possibility. In my SG I've got this hooked up to the push/pull tone pot. Next up, I fancied adding coil splitting for the two humbuckers, mainly because I had a spare push/pull pot kicking around... This was made slightly harder because the standard Epi pickups are only 2 conductor, however you can adapt them for coil splitting by removing the tape round the coils, and splicing a wire into the link connecting the two coils together. When this wire is connected to ground by the push/pull pot, it grounds the first coil leaving just the other for a single coil-ish sound. For the bridge this is relatively simple, just grounding through the pot body to the main shielding ground, but the neck pickup needs another wire running back to the 4PDT. This is necessary so all the connections to the neck pickup are removed when the sustainer is on. I've got a very rough schematic of all this lot drawn up, when I finish it off and if it works I'll smarten it up and post it, someone might find it useful, I certainly found figuring out how to get the sustainer integrated into the guitar one of the harder bits to figure out. Link to comment Share on other sites More sharing options...
megadog Posted October 3, 2008 Report Share Posted October 3, 2008 Guys thank you so much for that and no its not negative at all. I understand is a very complex process and i fully get what your saying. Your right. The first step is to build up the circuit for the pickups and also to build the sustain system ( driver, preamp and circuit).then to incorporate the two together. I really appreciate all you've said and am only really annoyed at myself that I can't understand everything. So i guess from here i should really focus on gathering as much information as well as all the necessary components for the build/testing piece. Thanks for being so helpful to a complete stranger. You guys rock. Link to comment Share on other sites More sharing options...
psw Posted October 3, 2008 Author Report Share Posted October 3, 2008 That's ok... the thing really isn't that "complex" but it is tricky and some of the problems tht will happen need to be overcome on a case by case basis...a lot of plans can be made but end up being revised... I've got a very rough schematic of all this lot drawn up, when I finish it off and if it works I'll smarten it up and post it, someone might find it useful, I certainly found figuring out how to get the sustainer integrated into the guitar one of the harder bits to figure out. Seeing how others have approached and solved their own problems is really what this thread is about...thanks for giving me a hand there...dibsmjf As a result I'm using a recently donated Epiphone SG, which I don't mind knocking lumps out of, dropping blobs of solder on and generally abusing. There is no need to "risk" a guitar like that...it is likely possible that no "lumps" are required to be removed either...but it depends on the guitar and the ingenuity....the battery has to go somewhere though, and it needs to be accessible! Building the circuit and a driver all you need do is solder a pair of wires from the bridge pickup to the circuit, use the battery to turn it on and reverse the wires to the driver to get a harmonic effect...holding it above the strings well away from the neck pickup. Once shown to be working...you may choose to make a better driver, or transplant your first effort (rarely as good as a second attempt ) into the guitar and think about switching and stuff. True, it is a good idea to see if it is even possible to start with...but the details can be worked out later with a lot of guitars. The guitar nuts project has a very complex wiring scheme and three pickups yet seems to be possible. The problem with the 4 knob scheme is not only too many knobs, but at first glance the neck pickup will be connected via a common ground...with a bit of work, you may be able to get the grounds from the neck and bridge pickups separated...but a lot of logic required that I don't quite have the patience for lately...it would be interesting if someone can work it out... ... Generally, as much soldering as possible outside a guitar is preferable...on something complex you can mount the controls on a cardboard template then implant the assembly once tested into a tight cavity...this ensures ease of building, good solder joins, no melted wires, good light to work with and ease of changing or fixing things. On a guitar like a strat the scratchplate allows you to do this...in fact it was leo's idea (along with bolt on necks and any number of useful innovations) to design it like this for ease of manufacture! anyway... something to think about...going back a few pages might give you a few more general ideas, see where others have first joined and how their project progressed and I have answered common questions... pete Link to comment Share on other sites More sharing options...
megadog Posted October 3, 2008 Report Share Posted October 3, 2008 I was just wondering if anyone could suggest a good circuit diagram for the preamp system. Sorry to be a bug. Link to comment Share on other sites More sharing options...
psw Posted October 3, 2008 Author Report Share Posted October 3, 2008 The fetzer in the fetzer/ruby circuit is the preamp...have a look at recent pages, risingforce as I recall posted something in response to my suggested modifications to this circuit a few pages back... Link to comment Share on other sites More sharing options...
megadog Posted October 3, 2008 Report Share Posted October 3, 2008 Cool thanks. Link to comment Share on other sites More sharing options...
psw Posted October 3, 2008 Author Report Share Posted October 3, 2008 Ok...with the F/R...have a look a page back or so about my mods and risingforce's attempt to do a layout of them for the F/R...perhaps it needs another name! The signal goes from the bridge pickup to the input of the circuit and then onto the switching and controls. Not through the circuit, but both attached to the input of the circuit, only the driver goes to the output. There are variations to get the same effective wiring and it would appear that you have got that bit right! Ok pete, but what is disturbing me is that the original bridge signal is splitted in 2 parts and go to the F/R input AND the guitar controls (I consider this wiring in "paralel"). Have a look at my scheme (Based on a typical wiring diagram from SD) : In this case : is the signal of the bridge pickup divided ? Most likely however, you haven't said what kind of circuit you are using and the kind of thing you are describing sounds like "loading effects". If the circuit you are using expects a line signal, and you send a guitar into it, the "impedance" will be all wrong. An MP3 player might work, or computer, because these have preamps in them to boost the signal to the correct impedance, a normal guitar does not. Worse, if you try and share the signal between the circuit and another amp like a guitar amp...the tone and everything suffers greatly and the performance of the sustainer effected too. It might work a bit, but not as well as you might hope. In the F/R, the fetzer transistor stage allows for a huge range of signals preventing the signal from getting "loaded down" and optimising the signal for the "poweramp LM386" stage (which does most of the work). So, if it is working 'kind of', this may be so, but it will work even better without the loss of tone with a proper circuit. So, extremely well done and it sounds as if you have taken all my recent advice and taken it in stages and prepared to redo the driver if necessary...congratulations. You pointed it ! I used a little guitar amp to do the job, but i know that I have to make the F/R soon (I'm waiting for some components right now) for improving my tests; When I told you that I have larsen and EMI, I had only the bridge pickup and the center single coil on the guitar. Neck pickup has been replaced by the driver. BTW, I plan to wind a special pickup like yours, which will have a typical 0.063mm (AWG42) wiring for the passive pickup stage, and a special stage above with 0.2mm wire for the driver, but it'll be another story ! Best regards Strib Perhaps people need to go back and look around this area for circuit ideas...this was around 262 or something...I couldn't find risingforces version, but it looks like scrib used it at this point (there may be more from scrib in the tutorial if I remember copying it there with an alternate circuit)... Also...please use and support the DIY layout creator software Link...there is a tutorial there at this link....but also a FR and the fabulous free software that will allow you to post ideas and send them to me in which I could modify them till we get something that works... I am sorry that I personally can't afford as much time and energy as I once did on developing and tidying up these things...but maybe together we can get something a little more concise... hope that helps a little...I know more reading... pete ps...clicking on the little pink arrow on the above quote takes you to that part of the thread directly... Link to comment Share on other sites More sharing options...
Desjay Posted October 7, 2008 Report Share Posted October 7, 2008 (edited) How's everybody doing? I'm new here, but I've been following this thread with a lot of interest, PSW, I've read 100+ pages of this thread, and man, I've got to say I feel like I've known you for a lifetime Anyway, PSW, you got me thinking (which, to some people who know me, is pretty dangerous) And I hope it's OK for me to post a different branching of the sustainer idea I've been working on in my head, and hope this won't be taken as a deconstruction of everything that's been covered so far. My idea, keeps obsessing me back to the original patent drawings of the E-Bow, along with some promising info from someone's website, that has participated in this thread, on his website he actually tears apart an Ebow, (kind of wish he had a heat gun to try and remove all that epoxy or whatever is covering the entire circuit board ) Anyways, he did take some good photos of the magnet/coil assemblies inside the Ebow and dammit, if they didn't almost look exactly like the size of those hearing aid/camera batteries So, I'm not sure how accurate patent drawing need to be, the patent itself was issued in 1975? IIRC, and the circuit looked like a basic 741 op-amp circuit to me, (I also don't know if the lm386 was out yet, and internet searches couldn't give me a year for the lm386) So, I decided to think my plan through with an op-amp My idea focuses on the OTHER part of the patent, the polyphonic Ebow, I found a place that sells any shape of magnet and any size here (this is the Ceramic Magnet selection page, they also have every other type also) http://www.magnetsource.com/Solutions_Page...SCSceramic.html Every diameter and height etc..... So I figure I could get the round ones, maybe .5 dia, and .25 height (maybe more) Glue some plastic discs on each end and wind up these mini-coils Kind of like a (I believe it was) Dan Armstrong Pickup, that had an individual Coil for each string (Someone correct me on that if I'm wrong) Now looking at the Ebow, the Driver and the other coil are in-line with the string they sit over and are probably .5 inch apart, so I'm thinking, why not replicate this 6 times, and put them under each string, inside a housing like a humbucker housing or Music Man housing or those other big honking pickups that go on a bass? Now....if the proximity of the driver and coil in the Ebow ALLOW the use of Op-Amps (not sure), then why not go with an LM324 Quad op-amp, and one more Dual op-amp from the same family, to save space? Then you would end up with a row of drivers and then a row of the other coils D D D D D D O O O O O O like that, each with their own circuit to drive each pair of driver and coil, which would/SHOULD allow polyphonic string feedbackage My OTHER thought, because PSW experimented with this already and mentioned the problem of once you bend the string, you move it out of the magnetic field, is 2 options 1. Maybe putting the assembly closer to the bridge where string bending won't be as extreme as it would be, if the units were placed near the neck....OR 2. instead of going with ROUND drivers and Coils, try Rectangular ones that "overlap" like this: Drivers and string number: .1..2..3..4..5..6 ___ ___ ___ ... ___ ___ ___ ___ ___ ___ ... ___ ___ ___ Same with the coils (Ignore the periods, I'm just using them to show the offset of the coils, the BB formats the stuff so they line up) So, the elongated coils and drivers that overlap will maybe keep the string ringing. now PSW you've also done quite a bit of research in the magnetism area, and I can't honestly say, if overlapping the drivers and coils would interfere with each other horribly or not, but maybe if they are staggered about .5 inches it might help? If someone would like to let me know if this branch is feasible by all means let me know, if anyone wants to completely blow it out of the water, well, again, let me know. I just feel there's an approachable solution to the (obviously unmarketable) device because EBOW already has it patented, and I honestly don't see why something like this couldn't be implemented. Power-wise I'm not sure, seeing as I use a Roland GK3 I've been hoping I could just tap off the 7 volts coming from that. (This would probably be easiest to implement on a guitar with a pickguard and the "Swimming pool" pickup routing) Edited October 7, 2008 by Desjay Link to comment Share on other sites More sharing options...
psw Posted October 7, 2008 Author Report Share Posted October 7, 2008 If someone would like to let me know if this branch is feasible by all means let me know, if anyone wants to completely blow it out of the water, well, again, let me know. OK...Bang...sunk! welcome to the sustainer thread! Link to comment Share on other sites More sharing options...
psw Posted October 7, 2008 Author Report Share Posted October 7, 2008 Actually...I was doing a fair bit in this direction...but there are many aspects of your proposal that simply won't work...here are some reasons why... The ebow uses a LM386...you can't use an op-amp like a 741 because it is not designed to drive a speaker...it will boost a signal like a preamp...but not drive a load... Making 6x8 ohm drivers may take more space than you assume...remember that with the formula that makes my design works (0.2mm wire) it takes a much larger coil than would fit into the 10mm allowable between the strings (that said, I did find a way with the hex drivers...but they have other problems)... BTW...Paul M from DIY guitarist and member here bought that ebow and you can see the details at his site... The separation required to stop oscillation is a lot more than would fit into a HB housing. You may think that the ebow coils almost fits in there...but it is only one...having 6 that close would generate EMI that would inevitably leak into the other pickups and drivers. Hex coil pickups have been made by many...typically they are wired in series and have HB qualities...however...a pickup coil of only 10mm would not have the power of a normal pickup coil and be very low impedance...it would therefore require a fair amount of active boost (that is where your op-amps could come in handy)... Six drivers would require, six amps...and so up to six times the power to run it... In order to have true independence...you would need a hex pickup to run it and separation similar to the bridge neck combination...so no benefit there...disregarding that the drivers would all be magnetically coupled anyway! The ebow patent is getting pretty old now...this may explain the moog guitar... ...they use substantial circuitry and remote power from a box on the floor to the mains (so I am led to believe)! My OTHER thought, because PSW experimented with this already and mentioned the problem of once you bend the string, you move it out of the magnetic field, is 2 options 1. Maybe putting the assembly closer to the bridge where string bending won't be as extreme as it would be, if the units were placed near the neck....OR 2. instead of going with ROUND drivers and Coils, try Rectangular ones that "overlap" like this: The rail thing isn't necessary...there may be a little drop out but with my new wafer coils on strat pickups...it is hardly noticeable...string bending often will bend a string over the next pole anyway...but it is not as focused as all that. My hex designs were extremely focused to try and address the cross talk issues between the 6 drivers...however, because of this they had some bizarre symptoms if out of alignment...the solution was to attempt to mount it in the bridge...but there are problems there and they were not so focused that they could be used with the bridge pickup...potentially the neck pup only...but I abandoned this around that stage... like that, each with their own circuit to drive each pair of driver and coil, which would/SHOULD allow polyphonic string feedbackage Some people worry excessively about this. I should make it clear...the sustainer with a single coil is polyphonic! Generally it favors the low strings but there is no problem playing chords (as you can here in the sound clip linked in red below)... This can have some musical advantages anyway...however the response could be more even ideally...but the lengths required to get there may be a little extreme. The effect people want in this regard is more the kind of thing that can be had already with sampler and synth technology. Remember...this device has the effect that a super loud amp has, with the correct positioning and complete control...without the volume or the distortion...this is what it does! Now...if you actually do play a loud guitar...the feedback effect is exactly the same...it tends to favor the lower notes, etc... Santana has exploited the effect more conspicuously than most...to that end, the device as is, is very effective... It is when people expect the guitar to become like and organ or something...that problems emerge and misunderstandins come up. Some of these ideas have been discussed in various threads in the general section if you want even more reading...search electronics section for sustainer! ... Anyway, PSW, you got me thinking (which, to some people who know me, is pretty dangerous) That is the idea! And I hope it's OK for me to post a different branching of the sustainer idea I've been working on in my head, and hope this won't be taken as a deconstruction of everything that's been covered so far. No...this thread is about sustainer ideas...anyones ideas...anything really, ebows sustainers...even some of the elctronic solutions...vibrating the whole guitar with piezos if you can find a way! People do not have to even be making one or want to...and even ideas that might not work might spark and idea that would... I hope people can benefit from my experience...maybe prove me wrong (I have proved myself wrong enough...so reading the whole thread could be misleading)...but that shouldn't really stop people as long as I can say I told you so! ... So...welcome aboard...a lot of this thread is a bunch of guitar geeks waxing on about obsessional things...but that applies to PG in general...in fact the whole internets! I've got to say I feel like I've known you for a lifetime You know...the last five years of my personal life have been the worst of times and the most tremulous that you could imagine. I'd like to thank all those people who have stuck with this (even for a while back in 2005 when I was living in a car!) and become good friends over the years, and still today. I also appreciate all the new people and there have been many times that the distraction of putting mind to these esoteric issues have kept me here...so thanks to everyone... The discussion of ideas brings people much closer than discussions of opinions and I think that is one reason that this thread has lasted so long...no one wants it to end! pete Link to comment Share on other sites More sharing options...
Desjay Posted October 7, 2008 Report Share Posted October 7, 2008 The ebow uses a LM386...you can't use an op-amp like a 741 because it is not designed to drive a speaker...it will boost a signal like a preamp...but not drive a load... Making 6x8 ohm drivers may take more space than you assume...remember that with the formula that makes my design works (0.2mm wire) it takes a much larger coil than would fit into the 10mm allowable between the strings (that said, I did find a way with the hex drivers...but they have other problems)... OK..... well shoot...... :/ Well, thanks for getting me excited about electronics again, I was really into it in the late 70's early 80's, making a lot of stuff from the Craig Anderton book, and even building a drum machine from a block diagram using CMOS 4017;s etc, (I used to have all the numbers memorized ) One project (The Craig Anderton Pre-Amp) ended up with me having a pretty wild looking guitar. Picture a plastic battery pack screwed to the front of the guitar that can hold 4 (or was it 6?) C Cells, the guitar Out Jack with a cord plugging BACK INTO a guitar Input jack in the pickguard, with another cable coming out of the pickguard going to an amp....yea, my guitar had 3 1/4' jacks on it, and I had a 6 foot length of cord just hanging from the guitar between the IN and OUT of the preamp. Don't know why I didn't mount it INSDE the guitar, considering it was an old Mustang shaped Silvertone that I carved into the shape of an SG with one of my Dad's Skinning Knives and a Hammer....all the Luthiers here just fainted LOL!!! What got me thinking of that approach was the proximity of the two coils inside the ebow, along with how small the coils themselves were. Well, I'll either experiment anyway with that approach (with several severe modifications, like using the LM386) or I might try two 'bars' (driver and Coil) placed near each other like the ebow. Either way, it'll be cheaper to experiment than to buy Five more Ebows My initial thought was that the circuit would need less "whatever" to get the string ringing because of the closeness of the two coils/drivers (whatever the official designation is) Link to comment Share on other sites More sharing options...
psw Posted October 7, 2008 Author Report Share Posted October 7, 2008 Well...far be it from me to tell you not to experiment... It may be a long and frustrating time though and it is worth considering the ultimate goal more critically...still...there is no doubt that anyone that has been involved in the project has learned a lot... One thing that people should note that the circuit is there to provide an electrical signal of the strings...it is the driver that needs to transform it back into magnetic energy and move the string...this is not a simple signal processing problem like an effects box and what you are working with is magnetic energy and the physical movement of the string. My designs are such that the driver coils are "fast" enough to work with a very simple amplifier circuit...commercial sustainers don't and even the ebow can compensate for phase difference by physically moving along the length of the string... To illustrate this and other problems you face... Consider a transformer. This device typically consists of two coils around a common core. If you apply power to one coil, you get power out the other coil ~ yet they are not physically wired together! The two coils are linked as if they were wired by magnetic coupling through the common magnetic core... Now...you know that if you have two magnets close together they seek to attract or push away...regardless, they are linked by their magnetic forces. Coils, magnets, metal cores...all can become effective magnets with an AC current running through them...that is electromagnets. The vibration of a metal string even, creates an AC current in the sensitive coils of a pickup for instance...equally, it would pickup the influence of a magnetic field like a transformer of your computer monitor... SO...what I am trying to illustrate...way to early in the morning here...is that when magnets, coils and metal objects are within close proximity to these devices...there will be an effect. With pickups...the effects are fairly small, but with our drivers...the effect is purposely large (we are applying current through the circuit to it)... I say "the effect is purposely large" because it is exactly this magnetic energy that we want to put out to move the strings. So...if you have two coils, magnets and metal objects (eg strings, cores, etc) very close together...you will have virtually wired them together...they is they will interact! ... I know...the eBow then seems like a paradox...but there are a number of important differences. It is completely self contained (the ebow pickup is not used by the guitar nor wired to it's circuitry) and it only needs to work on one string at a time. The coils of both pickup and driver are heavily shielded much like a speaker coil if you look carefully. It also works in isolation...it is not working with other exposed coils in the vicinity. The sound of the ebow (though I have not played one) will get into the guitar signal through the pickups and they put this forward as a feature An ebow is portable and can slide along the string to find the best vibration points and phase relations between driver, pickup guitar pickup...but mostly...the nodes in the strings vibrations of a given note...something a fixed driver can't do! (both sustainiac and fernandes employ phase comensation and AGC to help with this in their designs...) ... A real life example of the problems is the feedback that occurs with a mic and a PA. If the microphone is pointing towards the speaker...it will hear itself and start a self oscillation loop (squeal). The solution is to move away, angle away...or turn it down. Turn it too far down, and it wont be loud enough...turn it up too far, and it will squeal anywhere as the sound bounces off the walls! Jam the mic righ into the PA bin...and no amount of energy will prevent it squealing. Similarly...pickup and driver coils too close together means they will be magnetically coupled and self oscillate (this is different to the "fizz" distortion thing that even the ebow suffers in it's own way) and simply won't work. The whole project is a subtle balance of forces...magnetic, electrical, physical and temporal (time~phase differences) as well as proximity effects... The project and principles are easy...the things we are working with taken for granted...working with these things though illustrates how interlinked all these things are and amplifies the affects of each on one another... You will never look at things quite the same again...even a powerline in the wind...be warned! pete Link to comment Share on other sites More sharing options...
Desjay Posted October 7, 2008 Report Share Posted October 7, 2008 Wow Pete....... you've done your research You should definitely go to a music shop and let them let you try out an EBOW, you can get an open string vibrating so hard that it will bang against the frets, and even a pickup, if you have the pickup close enough, I swear it will have the string looking like it's a half inch wide (25.4mm) it's moving around so much, it's almost scary to touch the string when it gets going that strong because (to some who have done it) it almost gives you the sensation of touching an electric fence, because it's vibrating so hard. OH Well, I'll keep messing around here and let you know if I come up with anything, I don't want to derail the thread too much with my "I think this will work" posts Thanks again Pete Link to comment Share on other sites More sharing options...
psw Posted October 7, 2008 Author Report Share Posted October 7, 2008 Wow Pete....... you've done your research No, no...I've made my mistakes and tried to learn... The sustainer will also do that...I remember the first time I saw the string jumping about...I showed my daughter and she was amazed at it....I caught her sneeking in and trying it just to see the thing move... Part of the attraction of these things is this "magic"... The ebow is particularly good at it because it is only picking up the signal from one string...no cross talk...and the driver only driving that one string..plus you can move it to the most advantageous spot and it can draw on the magnetic energy of the pickup. Get close to the pickup...and it pickups up the sound emanating from the driver too... A sustainer has to put out more energy and the resonance of the string decides from the mono signal how it will vibrate from this mix of signals. The fundamental mode sustains chords better, as the physical properties of the strings are better able to 'filter' what parts of the signal will drive them... The problem is as I say...the cross talk between driver and pickups that are intrinsically magnetically linked at any close proximity and avoiding the pickup hearing the driver and so going into oscillation when powered up enough to move the string. pete Link to comment Share on other sites More sharing options...
Inea Posted October 8, 2008 Report Share Posted October 8, 2008 Hi there, I've read alot on this thread and started to built my own sustainer. I was able to built a 8ohm driver, which I didn't expect to be that easy to build. :-) As preamp I've built the little gem amp, but it has no transistor preamp. I've connected everything as it says in your pictures, but it just gives me nasty high pitch noises. Doesn't it work because of the Little Gem? Do I have to build the F/R? Link to comment Share on other sites More sharing options...
mrjstudios Posted October 8, 2008 Report Share Posted October 8, 2008 As preamp I've built the little gem amp, but it has no transistor preamp. I've connected everything as it says in your pictures, but it just gives me nasty high pitch noises. Doesn't it work because of the Little Gem? Do I have to build the F/R? You do need a preamp. The little gem or ruby or any 386 based amp by itself does not work well -- I have tried that long ago hoping to skip having to build a preamp, and it did not work. The squeeling could be a number of things: You don't have a preamp, Your driver could be too close to your pickup, You circuit might have errors in it, You might not have your circuit grounded to the guitar's electrical system correctly, Your driver may be oscillating because the internal windings are loose etc. etc. I am currently working on a circuit that will be much more suitable for DIY sustainers than the Fetzer Ruby, but that is similar to it and easy to build. It employs all the mods that PSW has suggested for the F/R, and a few more. Until I test and post it on the forum though, the Fetzer Ruby is your best bet. If you don't mind waiting a few weeks though, then you can use mine once it is done. Link to comment Share on other sites More sharing options...
Inea Posted October 8, 2008 Report Share Posted October 8, 2008 Thanks for the reply! At the moment I am quite frustrated and I'll take my time before starting another attempt. I've tried to built the F/R, but it is difficult to get a J201 where I live, so I had to use a BS170 and although I considered the different pin layout it didn't seem to work. Ill start another try once I've got enough money to order new parts. :-D Link to comment Share on other sites More sharing options...
psw Posted October 8, 2008 Author Report Share Posted October 8, 2008 It is the middle of the night here...so a little more sleep required... hoping to skip having to build a preamp, and it did not work. This seems to be a recurring theme...it is an extra couple of components...(MRJ realizes this...however...) the preamp is vital for the purpose of input impedance matching so as not to load the pickups... it is difficult to get a J201 where I live I am not sure where you live? (this can help BTW)...but you can't get them in Oz easily either... However...there are suitable replacements...but any preamp design using a preamp or opamp that doesn't intend to induce distortion will work. You can even run a stompbox before it to test the LM386 and use it's internal buffering for that purpose... Also...the Runoffgroove circuits have intentional "faults" in the circuit design for reasons only they know. Most of my suggested modifications to the F/R have been taken directly from the manufacturers suggested data sheet to keep the chip happy. As for the driver...need to see a pic. It is not hard to wind, but sometimes...like in with leaving out the preamp and expecing it to work...people take "shortcuts" like not using glue to pot the thing...again vital... However...the driver is easy to wind...so easy that a little glue on the hands is worth it...and easy enough to be not too much of a chore to do it a second time if the first wasn't so good... In this case though...you are probably experiencing loading and oscillation effects and you won't know if any driver is any good till you fix that... There could even be other issues...a pic and or better description of where you are at will help a lot! pete Link to comment Share on other sites More sharing options...
psw Posted October 10, 2008 Author Report Share Posted October 10, 2008 OK...so some off topic news...although I have been doing some "housework" around here and looking into making a limited number of these fireDrive circuits up and today's work is moving in that direction...more on that later... ... So...I have another project that I am thinking of putting an effort into and could interest people...I have started a thread here but it is in the early stages and things have not gelled yet, so it is a good time to make suggestions and see how I tend to work (or not) as the case may be. Looks to be a fun thing and like the sustainer an innovative project for people who like to push some boundaries... Here the thread...JazzStrat Project...it is linked on my signature too... I bought a bunch of these things...but this one I started messing with a while back...I am working on the cheap here... It is a jazz guitar like body with a strat neck and a mini HB...I also want to install a piezo with 4 band EQ preamp and digital chromatic tuner! But as always...that's not all... The onboard tuner and the larger body size made me wonder...maybe it is time to revisit my multi-tuning tailpiece idea... The idea is to fabricate a tailpiece with individual levers for each string that...well...here's a quote... Anyway...the idea is you tune the guitar to standard tuning but each lever will lower it's string down a half or full step according to the setting of the stop screw... The result would be that you could do tunings like 1> standard 2> drop the low E to D for a dropped D tuning 3> drop the low e and high e for a double dropped D tuning (provides 3 open octave strings) 4> drop the a string to g...giving open g with the above 5> drop the b down to a with 3 for DADGAD (common celtic tuning...think J.page) 6> drop g to f# with 5 combination to get open D tuning You could even use the levers as benders in dropped tunings to bend strings while playing a chord...hehehe All of these could be changed on the fly so you could combine them into a song...or you could quickly change tunings without retuning the guitar... Needless to say...a successful implementation of such a thing would be something special. If you have ever seen adrian legg do his thing with his set stop banjo tuners...you will get an idea of the kind of thing that's possible with this kind of thing. As the tuning drops...it adds no extra strain on the neck and as well as these 6 tunings...there are other possibilities and combination's I suppose that might be useful... The mechanisim needs to be able to pull (most likely) the string with a lever depressed so needs a fair amount of leverage to make that practical. It needs to lock into the down position for standard tuning with some kind of catch. The levers need to lift up (the string tension will provide the "spring") to a point adjusted probably by an allan bolt to a preset lower pitch. On previous attempts...I tried to build a mechanism that might fit into a strat's tremolo spring cavity...this one might be easier to realize as there is a fair amount of room between the end of the guitar and the bridge... Most likely I would be fabricating the thing from aluminium section... Anyway...early days but anyone with a little mechanical sense or ideas from gadgets you may have seen around the home...post a reply at the other thread...or an opinion even (too ambitious?) pete Link to comment Share on other sites More sharing options...
dibsmjf Posted October 11, 2008 Report Share Posted October 11, 2008 Hi Pete, The jazzstrat looks interesting. How about a mechanism similar to a capo with an overcentre hinge and a screw to adjust the position is flips to? Got all the wiring finished in my SG today, I've gone for a seperate pre and poweramp connected by half an inch wires for power and signal, makes the assembly flexible so it will stow in the corner of the control cavity-will try and take some decent photos later on. I've gone back to the Fetzer style preamp, seems to work ok running into the amp and into a small speaker, quite a bit of distortion on the loudest notes. I've tried a few different transistors, including a random from a previous project which turned the whole lot into a fuzz. I've gone back the J201 at the moment, seems to give the best balance of higher output but not too much distortion. I'm not totally happy with it, but will see how it works with a new driver. Interested to hear you are putting some more of your circuits together, are you still thinking of putting these up for sale? Irrespective of whether I get my circuit working to my satisfaction, I would definitely be interested in purchasing a fireDrive. Assuming you build in a decent profit margin into the price, it would be good to give something back to you! Link to comment Share on other sites More sharing options...
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