psw Posted April 17, 2007 Author Report Share Posted April 17, 2007 Good to see people are prepared to get into the spirit of the discussion here about exploring other and related ideas. I'd still like to look into a few pickup ideas in the near future, which is what I originally intended to do. I think there is room for some more in the way of active pickups besides just EMG's for a start. It may not necessarily be that people need to stick to the standard HB and SC format if people are building custom guitars anyway, there are still some classic sounds to be had besides variations on these two, look at the P90 and bass players have no problem seeking out different formats and active elements to the signal chain... There have been a lot of ideas in the patents if you wish to search, one over a hundred years old! There is one for instance for a speaker that is held in the palm of the picking hand to get feedback...well that's the idea, but I don't see it as practical, or even possible (squeal machine most likely). I still like the vibration idea and did a few experinments figuring that the pivot of the strat bridge and it's spring cavity offered some possibilities, but generally you are looking at a fair bit of power, probably a bit of noise, EMI and dealling with mechanical problems. The magnetic sustainer and Ebow like devices offer no moving parts, no vibration or noise and an efficient stealthy solution, so that is likely to be the focus for some time... back later... pete Link to comment Share on other sites More sharing options...
psw Posted April 17, 2007 Author Report Share Posted April 17, 2007 OK, I'm tracing alot of my problems back to a high pitched sound produced by my Ruby/Fetz circuit. I find that if I touch the ground/common with my hand, this problem mostly goes away. I don't get it because I only touch the ground, nothing else. This problem is NOT related to feedback between the pup and driver because the loud ringing is apparent when the amp outputs to headphones. This high pitch squeal causes microphonics in my driver that wrecks the efficiency of it. How do I fix this problem so that I don't always have to be in contact with the ground? I think there may be a problem with the trim pot (see the main diagram), but could that be causing it? Thanks! This may be a blessing, at least you know it is not the driver but something wrong with the circuit. You seemed to say that the circuit worked previously. Could it be that something has shorted out somewhere when you made your connections or something gotten damaged by heat? I will have to leave this question to more knowledgable people to troubleshoot your circuit for lack of time I'm afraid...good luck... pete Link to comment Share on other sites More sharing options...
psw Posted April 17, 2007 Author Report Share Posted April 17, 2007 I am assuming this is the circuit you used, I am not sure if this has been verified or if this will help troubleshoot your problems. This is a quote from the tutorial and the little pink arrow in the quote will take people to this part of the forum... pete Link to comment Share on other sites More sharing options...
Avalon Posted April 17, 2007 Report Share Posted April 17, 2007 (edited) OK, I'm tracing alot of my problems back to a high pitched sound produced by my Ruby/Fetz circuit. I find that if I touch the ground/common with my hand, this problem mostly goes away. I don't get it because I only touch the ground, nothing else. This problem is NOT related to feedback between the pup and driver because the loud ringing is apparent when the amp outputs to headphones. This high pitch squeal causes microphonics in my driver that wrecks the efficiency of it. How do I fix this problem so that I don't always have to be in contact with the ground? I think there may be a problem with the trim pot (see the main diagram), but could that be causing it? Thanks! I think you need to get the Multi-meter out mate (if you have one), set it to buzzer mode, tap the two contacts together and it should bleep or buzz to let you know the two surfaces are connected. Now start checking all the shielded areas, if you have a crocodile clip adaptor for one of the contacts, clip it on to the shielding side of your PCB, and use the other contact to check what is and isn't connected to it. Make sure all the inputs & Outputs shieldings are connected, and make sure the shielding isn't making contact with any other area of the PCB (or its components), and if you need any help with this, i'll make alittle Pictorial if its any help. Good to see people are prepared to get into the spirit of the discussion here about exploring other and related ideas. I'd still like to look into a few pickup ideas in the near future, which is what I originally intended to do. I think there is room for some more in the way of active pickups besides just EMG's for a start. It may not necessarily be that people need to stick to the standard HB and SC format if people are building custom guitars anyway, there are still some classic sounds to be had besides variations on these two, look at the P90 and bass players have no problem seeking out different formats and active elements to the signal chain... There have been a lot of ideas in the patents if you wish to search, one over a hundred years old! There is one for instance for a speaker that is held in the palm of the picking hand to get feedback...well that's the idea, but I don't see it as practical, or even possible (squeal machine most likely). I still like the vibration idea and did a few experinments figuring that the pivot of the strat bridge and it's spring cavity offered some possibilities, but generally you are looking at a fair bit of power, probably a bit of noise, EMI and dealling with mechanical problems. The magnetic sustainer and Ebow like devices offer no moving parts, no vibration or noise and an efficient stealthy solution, so that is likely to be the focus for some time... back later... pete Im going to keep testing the sustainer too, the driver the above sound sample was recorded with was my first humbucker driver (7 ohms stacked humbucker (2 x 3.5 ohms), which works quite well, is far quieter then the single coils too (which is the general idea i guess lol). I might try another HB but a more powerful one to be wired in Parallel, as has been discussed on the previous page, that looks like yet another very interesting design. Edited April 17, 2007 by Avalon Link to comment Share on other sites More sharing options...
psw Posted April 17, 2007 Author Report Share Posted April 17, 2007 Im going to keep testing the sustainer too, the driver the above sound sample was recorded with was my first humbucker driver (7 ohms stacked humbucker (2 x 3.5 ohms), which works quite well, is far quieter then the single coils too (which is the general idea i guess lol). I'd like to know more about this one as the idea was proposed by me but never tried and there was a little debate about it....a diagram or a pic would be good too! I imagine that the parrallel trick could be employed with a stacked HB as well. pete Link to comment Share on other sites More sharing options...
Avalon Posted April 18, 2007 Report Share Posted April 18, 2007 (edited) Here it is: And: Each coil is 2mm high, wound around a 3mm thick steel core, and is about 5-6mm deep (including the core), and divided by 1mm plastic. I believe Dimarzio use the stacked coil on alot of there Humbucking Single-Coil pickups (HS-2/HS-3/YJM i think, and even 2 x 2 stacked coils side-by-side in the Seymour Duncan Hotrails if memory serves me correctly), and that approach appeals to me quite abit, which is something i might try if i ever get around to making my own pickups. Without trying a dual-blade driver, i can't really compair the two, but its a definate improvement over my single coil drivers, so HB's will be my focus for now as far as the drivers are concerned. I think i'll try a high power stacked HB around a 1mm core, to be wired in Parallel next (as has been discussed), and see how that compairs. Edited April 18, 2007 by Avalon Link to comment Share on other sites More sharing options...
onelastgoodbye Posted April 18, 2007 Report Share Posted April 18, 2007 NICE! Link to comment Share on other sites More sharing options...
uglogirl Posted April 18, 2007 Report Share Posted April 18, 2007 Hi, I have started building a guitar for my sustainer experiments and have read a quarter of the thread! I didn't find the answer to a simple question though... can I reverse the pickup and driver? I'd like the driver at the bridge and my input pickup at the neck because I rarely use a bridge pickup anyway. This guitar is a 24" scale with the standard stratocaster spacing between the bridge and neck and it will have the 12s on it - my usual strings. thank you, this is an awesome thread. Uglogirl Link to comment Share on other sites More sharing options...
uglogirl Posted April 18, 2007 Report Share Posted April 18, 2007 (edited) oh dear double post Edited April 18, 2007 by uglogirl Link to comment Share on other sites More sharing options...
Avalon Posted April 18, 2007 Report Share Posted April 18, 2007 The closer the Driver is to the bridge, the more powerful it needs to be to move the strings, which is why most of the testing is done in the neck position, as its closer to the middle of the strings length, and the closer you get to the center, the less effort it is to move them. A good example is to try closing a door by pushing it from the outer edge (the handle side), then try closing it from the inner edge (nearest to the hinges), it requires alot more effort, and the same sort of thing applies to the strings (the bridge & nuts are the hinges and the center of the strings 12th fret'ish is the easiest point to move them by (the handle)). Anyway, enough of bad analogys lol, but i hope that explains it. I think the middle position will be a more realistic option, i think thats where alot of us would like to run it (i only have a neck & bridge pickup, so its ideal for me lol), i think this will be more likely then a bridge driver atm. Link to comment Share on other sites More sharing options...
psw Posted April 19, 2007 Author Report Share Posted April 19, 2007 welcome uglogirl, I wouldn't read all this thread but do check out some of the other threads linked at the end of this post on my signiture for a general idea... Great stuff...now that is interesting though, you have the magnet on the bottom so that the two coils are on essentially a more or less single magnetic polarity. HB pickups have opposing coils on opposing polarities and even stacked coils have internal magnets to create this effect in general....interesting.... This coould mean the possibility of such a scheme on top of a pickup perhaps or even such other concepts as an inner coil with another wound over it to provide active sheilding of EMI.... Now, to the question of the bridge driver. I did quite a few experiments with this with the Hex devices I was working on and have given this a bit of thought. It may well be possible... The closer the Driver is to the bridge, the more powerful it needs to be to move the strings, which is why most of the testing is done in the neck position, as its closer to the middle of the strings length, and the closer you get to the center, the less effort it is to move them. This seems to be at first logically true, however. I get a very strong response from notes played on the highest frets of my strat within 2cm of the driver, so the string end is very close to the driver (analogous to the bridge) and would seem to disprove this theory somewhat. So, what I would expect is some unpredictability of the harmonics, particularly the harmonic mode, as they are closely spaced towards the end of the string, though this too may be a trueism. It may well be possible to reverse the scheme and we have discussed a little the possibility of multiple driver/pickups on a guitar (though combinations of such devices would not be possible)... I think the middle position will be a more realistic option, i think thats where alot of us would like to run it (i only have a neck & bridge pickup, so its ideal for me lol), i think this will be more likely then a bridge driver atm. This is an exciting possibility as it addresses a few issues. It would allow the use of either or both the neck and bridge pickups; not necessitate the mdification of these pickups; remove the need for bypass switching; allow the sustainer to source signals from either the bridge or neck pickup or both for different driving signals...to name a few. There is also the possibility from a design/product point of view, that some of the circuitry (given the compact scheme of my thin driver model) to incorporate the poweramp into the driver design. This would have the advantage of not having high current EMI inducing driver leads running through the control cavities of the guitar and making the only circuitry required in the guitar the preamp/switching and battery. This also opens up the possibility of the "sustain box" idea...by removing the need for bypassing and driver leads (only signal and power supply need be lead to the driver), a "powered driver" (power driver...now there's a cool name) makes a remote box fixed to the surface of the guitar a more realistic proposition. The "sustain box" idea also takes some of the pressure of the circuit size and so more sophisticated circuits like col's become easier to fit... Of course, the ability to fit a mid driver is a necessity so it may be limited to strat type guitars perhaps...and you would completely loose the mid pickup function....the sustainer does require comprimise... So...the bridge driver has not been tested and may have unexpected results or even not work satisfactorily, but it is entirely possible, even with the present technology we have developed...IMHO! Thanks a lot for building a stacked design and proving it's merit Avalon, this has really encouraged me and prevented me from having to develop into unknown territory with the concept. It, with various variations, could provide a superior and easily built alternative to the rail or HB side by side format and by proving the merit of the concept, you will have encouraged further work in this area. I believe Dimarzio use the stacked coil on alot of there Humbucking Single-Coil pickups (HS-2/HS-3/YJM i think, and even 2 x 2 stacked coils side-by-side in the Seymour Duncan Hotrails if memory serves me correctly), and that approach appeals to me quite abit, which is something i might try if i ever get around to making my own pickups. I am not sure if the 2x2 approach was ever used, but stacked pickups are common and have had varied success in the past. In recent times, the concept has improved with the Kinman and Fender's new noiseless designs giving a very convincing SC type response and sound. I am hoping to get into a bit of pickup design myself in the future, so it will be great if people start to transfer some of the ideas we have explored here, to pickup designs. One thing that strikes me, for instnce, is how thin our driver coils are becoming. a 2mm bobbinless coil, for instance, may well serve as a bobbin plate for a pickup design and incorporate the two devices as I have done in my sustainer strat. There are other possibilities too, like adding the driver and pickup coils in pickup mode, winding a pickup coil over the driver coils for shielding, and a host of other possibilities yet to be fully conceived... Certainly enough to keep this thread going for a few years yet!!! pete Link to comment Share on other sites More sharing options...
FlashBandit Posted April 19, 2007 Report Share Posted April 19, 2007 PROGRESS!! I built a new driver that works like a charm. I'm having some weird problems though in harmonic mode, and I have a question. Basically, it seems like the sustainer is trying to "force" a high pitched F# no matter what I'm playing. If I'm playing on the upper strings, the low E will start to resonate at an F# which is insane since they're not harmonically related (I don't think). What's up with that and how can I fix it? As a contribution to the ongoing driver development, 33AWG is very effective at driving the three highest strings. My coil has a 3mmx3mmx6cm core and no top bobbin. That way it can get closer to the strings. It's also 8.1-ish ohms. With my driver, it drives the three highest strings stronger than the bass strings. In fact, it does seem to have problems driving the A and D strings, but the E and three treble strings are fine. I'm thinking that it might work well to have two separate coils for the bass and treble strings, bass with 32AWG and treble with 33AWG. About EMI problems, couldn't you wrap the driver in metal tape and ground that? I think that should shield it. Or, you could wrap each driver and ground them. Just a thought. Link to comment Share on other sites More sharing options...
Avalon Posted April 19, 2007 Report Share Posted April 19, 2007 welcome uglogirl, I wouldn't read all this thread but do check out some of the other threads linked at the end of this post on my signiture for a general idea... Great stuff...now that is interesting though, you have the magnet on the bottom so that the two coils are on essentially a more or less single magnetic polarity. HB pickups have opposing coils on opposing polarities and even stacked coils have internal magnets to create this effect in general....interesting.... This coould mean the possibility of such a scheme on top of a pickup perhaps or even such other concepts as an inner coil with another wound over it to provide active sheilding of EMI.... Well i might not be doing myself any favours making it like that, but it does work, wheather its as effective im not sure, its equal to my single coils, but quieter, and i guess i'll only know if i test the other route. But the high power HB parallel will also be made like this, so i'll see how that go's, and probably try a dual blade HB too, so i can compair them. Now, to the question of the bridge driver. I did quite a few experiments with this with the Hex devices I was working on and have given this a bit of thought. It may well be possible... This seems to be at first logically true, however. I get a very strong response from notes played on the highest frets of my strat within 2cm of the driver, so the string end is very close to the driver (analogous to the bridge) and would seem to disprove this theory somewhat. So, what I would expect is some unpredictability of the harmonics, particularly the harmonic mode, as they are closely spaced towards the end of the string, though this too may be a trueism. It may well be possible to reverse the scheme and we have discussed a little the possibility of multiple driver/pickups on a guitar (though combinations of such devices would not be possible)... I think alot depends on where the drivers are, there are definately sweet spots on the strings, which probably relate to the position of the harmonics, so in theory if you have your driver under one of these sweet spots, i guess it might work quite well. On 21/22 fret guitars like Fenders etc, the neck pickup is directly under the 24 fret (or where it would be), which i think is the second best spot to being directly under the 12th, all my guitars have 24 frets (seemed like a good idea at the time lol), but i think with enough power, the drivers will work anywhere, its just a case of keeping them quiet thats the ultimate problem, and decent screening is something im yet to go onto, so any advise on that very welcome Thanks a lot for building a stacked design and proving it's merit Avalon, this has really encouraged me and prevented me from having to develop into unknown territory with the concept. It, with various variations, could provide a superior and easily built alternative to the rail or HB side by side format and by proving the merit of the concept, you will have encouraged further work in this area. My pleasure mate, its nice to contribute alittle back after all the devolopment you guys have put in getting this far Link to comment Share on other sites More sharing options...
uglogirl Posted April 19, 2007 Report Share Posted April 19, 2007 Hi Avalon, Pete, Thanks for the help! @Avalon Yes I know what you mean about the string being harder to drive from the bridge position. It is those string dynamics which I suspect causes me to like the sound of the neck pickup I would suspect. I was just thinking from an EMI standpoint, the bridge would be better but ideally, I'd prefer to have the driver in the middle. It would be SO cool to have it there with a Push/Push switch on the volume pot for turn-on. This guitar is set up for HSH PUs already. @pete, Sounds like I better just put things together so they can be moved aroung easily and try it out. I have a broken single coil I can use to make a driver with, also humbucker I can sacrifice, it has no other redeeming qualities. thanks again! Uglogirl Link to comment Share on other sites More sharing options...
col Posted April 19, 2007 Report Share Posted April 19, 2007 Great stuff...now that is interesting though, you have the magnet on the bottom so that the two coils are on essentially a more or less single magnetic polarity. HB pickups have opposing coils on opposing polarities and even stacked coils have internal magnets to create this effect in general....interesting.... I'm not sure about this Pete - the only info I could find when this was discussed a while back suggested that most stacked humbuckers are two coils wound around one magnet (ar at least a core with a uniform polarity). The two coils are connected out of phase, so you get hum cancelling, but you also get guitar signal cancelling (as you would expect). The reason it still works is because the lower coil is further away from the strings than the upper coil, so while it gets an equal helping of noise, it gets significantly less guitar tone (remember, the power is related to the square of the distance), so even with the cancellation, you still get a functional pickup. Unfortunately this suggests that it it less that optimal as a sustainer driver: #1 any cancellation is very bad for us because we need maximum efficiency #2 we're not so worried about noise cancellation, it's more about controlling and containing the flux of our magnetic circuit - just so happens that the same config works for hum cancellation and for flux control... Its good to hear that the stacked driver does work though, and it may be possible to tweak it using the tricks developed by Kinman et al. I would interested in some side-by-side tests done with a 'standard' dual rail driver. Now, to the question of the bridge driver. I did quite a few experiments with this with the Hex devices I was working on and have given this a bit of thought. It may well be possible... The closer the Driver is to the bridge, the more powerful it needs to be to move the strings, which is why most of the testing is done in the neck position, as its closer to the middle of the strings length, and the closer you get to the center, the less effort it is to move them. This seems to be at first logically true, however. I get a very strong response from notes played on the highest frets of my strat within 2cm of the driver, so the string end is very close to the driver (analogous to the bridge) and would seem to disprove this theory somewhat. So, what I would expect is some unpredictability of the harmonics, particularly the harmonic mode, as they are closely spaced towards the end of the string, though this too may be a trueism. It may well be possible to reverse the scheme and we have discussed a little the possibility of multiple driver/pickups on a guitar (though combinations of such devices would not be possible)... Yes, this makes sense because when fretting higher on the neck, the strings will be closer to the driver, the benefit of this could outweigh losses due to inefficient driver poisition. Installing the driver in the bridge position would alow the driver to be set permanently closer to the strings to balance the issue of the strings being harder to drive from that position. There may be issues, not just with less predictable harmonics from the sustainer, but also a general deterioration of the guitars tone caused by that strong magnetic circuit so close to the strings... I think its should still work though Thanks a lot for building a stacked design I second that Col Link to comment Share on other sites More sharing options...
Avalon Posted April 19, 2007 Report Share Posted April 19, 2007 Its good to hear that the stacked driver does work though, and it may be possible to tweak it using the tricks developed by Kinman et al. I would interested in some side-by-side tests done with a 'standard' dual rail driver. Well i'll try one of each at the weekend, a dual rail HB and a stacked HB, both the same rating, and see how they turn out. Just one quick question on the dual rails though, do you have one magnet facing both cores? (N facing one, S facing the other), or a magnet on the bottom of each core ? I've been searching the thread and can't find that info atm. Link to comment Share on other sites More sharing options...
col Posted April 19, 2007 Report Share Posted April 19, 2007 (edited) Its good to hear that the stacked driver does work though, and it may be possible to tweak it using the tricks developed by Kinman et al. I would interested in some side-by-side tests done with a 'standard' dual rail driver. Well i'll try one of each at the weekend, a dual rail HB and a stacked HB, both the same rating, and see how they turn out. Just one quick question on the dual rails though, do you have one magnet facing both cores? (N facing one, S facing the other), or a magnet on the bottom of each core ? I've been searching the thread and can't find that info atm. I did it with one magnet - N facing one core and S the other - just like most humbucker pickups... ============================ for the test, how will you make the comparisons ? can you set up a meter to take a reading of the current sucked from the battery at the gain that gives each driver a minimum acceptable sustain level ? I guess some stuff will have to be subjective - like how bad the fizz is, how even the response etc... mind you, it shouldn't be too difficult to see which can get closer to a pickup without messing up... I suppose that one driver will likely be more efficient than the other, so don't use a fixed gain setting for both in this test. Better to set each to give minimum acceptable sustain... else the less efficient will likely get closer to the pickup... can you also include a single core driver in the test (assuming you made one) ? are the magnets the same ? looking forward to the results good luck Col Edited April 19, 2007 by col Link to comment Share on other sites More sharing options...
mrjstudios Posted April 19, 2007 Report Share Posted April 19, 2007 (edited) I am assuming this is the circuit you used, I am not sure if this has been verified or if this will help troubleshoot your problems. This is a quote from the tutorial and the little pink arrow in the quote will take people to this part of the forum... pete That's the one. I made mine to that exact spec, but also soldered the pins 1 and 8 together. That design (with or without the pin 1 and 8 mod) DOES WORK for sustainer projects where the sustainer is wound to 8 Ohms. I'm about 90% sure that the pot between pins 1 and 8 can be removed, since the 2 other pots allow for "volume" which is sort of a pre or "gain" and and then a full circut "master" or "post" that controls the final output. Without the pins 1 and 8 on full all of the time, the thing hardly wants to work, and basically just screams a little less distortedly, but the overall intensity / volume is controlled with the other 2 pots anyway -- even if the third is there. I do still need to try some more tests with all 3 installed. QUESTION: How is a sustainer best mounted on a guitar? To the body directly? To a pickgaurd? To posts (screws) elevated off the body? Edited April 19, 2007 by mrjstudios Link to comment Share on other sites More sharing options...
psw Posted April 19, 2007 Author Report Share Posted April 19, 2007 Great stuff Avalon.... I did it with one magnet - N facing one core and S the other - just like most humbucker pickups... I think this is preferable unless you can get magnets small enough to be within the core as separate magnets may be attracted more to themselves below the driver and strings...still, it should work either way... It should be interesting as the dual blade driver vs the stacked driver offer different alternatives to pickup design and application of the driver...for instance a stacked coil may work atop a SC pickup and a HB a rail driver... mrjstudios the first trim pot (to the transistor) is not a volume control but adjusts the voltage across the transistor, it needs to be set to a specific voltage so that will need to be set and left (check with the instructions and see if this is correct as that may be causing problems). The other pot adjusts the signal strength into the LM386 poweramp section. The link between pins 1 and 8 changes the gain from 20x applification (without) to 200x (with the link), the trim would make this amount of amplification adjustable. Mine is linked with a 10uF capacitor which I think may help. I also think there should be a "zobel network" on the output, mine uses a 0.1 cap and 10k resistor between the output and ground. Here is the circuit I use for the lm386 part of this circuit. These caps are there to help with stability and oscillation... I also changed the 220uF cap to a 100uF cap to make it more responsive to higher frequencies... Many have found it works for them, but perhaps there are other concerns like the pickups on your guitar that means it needs a little more stabalisation. That squeel sounds like internal oscillation in the circuit than feedback with the pickups and driver. QUESTION: How is a sustainer best mounted on a guitar? To the body directly? To a pickgaurd? To posts (screws) elevated off the body? You don't want the driver to vibrate if possible, but it depends, mine as with most others are mounted just like a pickup in that neck position and are adjustable for height (important). PROGRESS!! I built a new driver that works like a charm. I'm having some weird problems though in harmonic mode, and I have a question. Basically, it seems like the sustainer is trying to "force" a high pitched F# no matter what I'm playing. If I'm playing on the upper strings, the low E will start to resonate at an F# which is insane since they're not harmonically related (I don't think). What's up with that and how can I fix it? Could be that the F# is the frequency of some kind of internal oscillation frequency. Also, it depends on your set up. If you still have other pickups in the guitar that are connected even if just to the ground, you may be experiencing problems in one mode that are not so apparent in the other... Hope all this helps... pete Link to comment Share on other sites More sharing options...
mrjstudios Posted April 19, 2007 Report Share Posted April 19, 2007 (edited) Yes PSW, thats sort of what I meant with the Pots, I just didn't say it as well as you did. Effectively, I mean the audio result, it is kind of like a sweet spot by using a pre and post level control on an amp -- if you know what I mean. Also, my sustainer doesn't scream. I was just refering to it when turned all the way up. It actually works very well, except the high E string that doesn't work at all (I need to mount and adjust the sustainer still; I've just been holding it over the guitar). Also, the 'harmonic mode' doesn't really work yet either since there is too much sustainer-pointing-at-pickup interference when I am holding the thing over the strings. I hope that will go away when it is mounted correctly on the guitar. I did get a few nice harmonics on the middle strings though when I held the sustainer way up towards the headstock so that the feedback went away. Also, does that "cap" between pins 1 and 8 lessen the gain to about 100X or so? Or does it just smooth out the full 200x? Mine actually is very clear even with those pins soldered together, so I'll leave it for now. Edited April 19, 2007 by mrjstudios Link to comment Share on other sites More sharing options...
psw Posted April 20, 2007 Author Report Share Posted April 20, 2007 Also, does that "cap" between pins 1 and 8 lessen the gain to about 100X or so? No, you still get the full power but some of the very high frequencies are filtered out that can cause problems, same with those other components. It actually works very well, except the high E string that doesn't work at all That is where changing to her lower 100uF cap instead of the 220uF can help. The idea is to amplify more of the higher frequencies. This may also help with the harmonic mode which also works in the higher frequencies. One side effect is that the lower strings in the normal mode may morph into a harmonic, as mine does, but that could be a feature, I kind of like the effect. What you want to do is get it working as efficiently as possible with as little power as possible to limit the amount of EMI that comes out of it. Mine though does run at full power! I hope that will go away when it is mounted correctly on the guitar. I do think that things improved when I mounted the device below the strings, but I wouldn't rely on this to solve problems, it sounds like it is well on the way to being successful... Good show... pete Link to comment Share on other sites More sharing options...
FlashBandit Posted April 20, 2007 Report Share Posted April 20, 2007 Mounting Question: PSW, you told mrjstudios to mount it and allow it to have an adjustable height and such. I made all my bobbins myself, so how do I mod them to let the height be adjustable? I'm mounting this in a strat in the neck position. Any suggestions for mounting? Link to comment Share on other sites More sharing options...
psw Posted April 20, 2007 Author Report Share Posted April 20, 2007 Well, you could glue it to a plate and mount it like a pickup, you could use springs or rubber tubing or something like neoprene from an old mouse mat to provide a spring. Same thing if surface mounted (not in the pickup slot) attach a plate to mount small screws and put some of this rubber "spring" under to adjust the height... Hope that helps... pete Link to comment Share on other sites More sharing options...
Avalon Posted April 20, 2007 Report Share Posted April 20, 2007 Well i'll be making my new drivers over the weekend (probably be mid week before i can test them), but i might alter my PCB to include some of your alterations from the "Champ" circuit above, see what difference that makes too. As for testing them, i guess the only thing you can actually measure is the ohms of the coils, the rest you have to take for a test drive, but when i have them built i'll let you know how they work. Link to comment Share on other sites More sharing options...
col Posted April 21, 2007 Report Share Posted April 21, 2007 Well i'll be making my new drivers over the weekend (probably be mid week before i can test them), but i might alter my PCB to include some of your alterations from the "Champ" circuit above, see what difference that makes too. As for testing them, i guess the only thing you can actually measure is the ohms of the coils, the rest you have to take for a test drive, but when i have them built i'll let you know how they work. You can rig it up with a meter between the battery and the circuit to measure how much current is being used - then test each driver when it is set to give a similar level of sustain - this gives a rough idea which is more efficient - which is one of our major priorities You do have to 'test drive' it for this, but at least it's just purely subjective - it is a measurement you can take - which is much more useful - otherwise it is difficult not to favour the driver that you want to 'win'... It's difficult for us diy bodgers to be scientific, but we should try to as much as possible, it will help us in so many ways Col Link to comment Share on other sites More sharing options...
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