psw Posted May 7, 2007 Author Report Share Posted May 7, 2007 Some great posts overnight (Australian Time) that brings things together a little of developments over the past year. I spent the entire day today fabricating some cores and bobbins to make a dual rail driver. Rather than go with the smaller drivers everyone else is making, I'm building this driver to just completely replace the neck humbucker. The first thing that came to my mind is to strip out the wire on your existing modified HB and rewind both bobins as drivers, blocking the lower part as you have already done, and running that with your existing system to see how that goes... One thing that has been debated a little is whether something as large as a humbucker is ideal for a driver. The distance between the two driver coils "may" give an effectively very wide core, something that we have debated is ideal. You will see that people have generally been making their cores thinner (down to 1mm), mine was fairly thin at 3mm. Col's driver works however and is similar in size to an HB, so the effectiveness of such a design is still up for experimentation.... Another thing that interests me with this kind of application primal is the potential to make a compact driver and incorporate the poweramp or the entire F/R circuit into the HB enclosure...just a thought... The magnet from your HB would be a good choice for a dual rail driver construction... It's interesting that we make such a distinction between the circuit and the driver - really it is all circuit, the driver and pickup are 'just' 2 more electronic components in the circuit. This way of thinking is what helped me to better understand the system as a whole. Hence thoughts about feed forward vs feedback, and other stuff related to harmonic modes and also how action is as important as string guage in deciding the success of the system. You are quite right of course, but it is useful to deal with the driver as a separate entity at times as it's design and construction can vary so much with each constuction and application... So, some nice posts and a range of choices there...good to see it come together like this, as I still have plans for my own guitar, but not a specific strategy. On my guitar (strat with bridge HB and no pickguard) there is enough room between the strings and the body of the guitar to fit a separate driver for instance. Then there is the choice of replacing the mid pickup with a driver. Other options could be to adapt shawns rail pickup into a dual coil driver pickup similar to my single coil version. A mid driver with no bypass requirements opens up the potential for the independant "sustain box" idea again for a low mod version. Too many ideas...and then there are these circuit options and the possibility of moving away from the LM386 to a BTL amp, or something of that ilk. Although others seem to have less of a problem with it, my switch off "pop" still bugs me, and I'd like to be able to demonstrate a more straight forward installation process... Could someone please post a standardized but very detailed diagram or set of pictures on how to build a dual-coil driver? Or a tutorial? Yes, always a problem, and the size of this thread is daunting and unwieldy..."standardization" is still a problem as each persons skills and resources and the application, the guitar, is so variable. Here, for instance, Primal is building a standard HB sized driver with no other pickups but the bridge (similar to col) but in my guitar 3 pickups and a driver of single coil size...quite a different proposition.... Good stuff as always... pete Link to comment Share on other sites More sharing options...
mrjstudios Posted May 7, 2007 Report Share Posted May 7, 2007 Thank you Onelastgoodbye! Brilliant! I'm gonna try a side-by-side dual 4ohm sustainer driver (wired in series). It will include (this is for those of you who want specifics for the experimentation aspect): 30 AWG Military Spec copper magnet wire (I think this converts to .2mm or .22mm gauge?) Iron bar magnet (like a single coil pickup magnet style turned sideways) Steel cores (custom cut out of .135in (3.36mm) thick steel barstock) White Plastic Parts cut out of a $1.50 garbage can from Target (great stuff) 'Potted' with Elmers Wood Glue (Yellow PVA) Metal Parts Superglued Together Powered by: Fetzer / Ruby amp from Runoffgrove.com (with pot between pins 1 and 8 replaced with plain wire or capacitor) Running on 9v Signal from a single strat style pickup. Entire guitar and amp circut (- gound) grounded to guitar body. -MRJ Studios Link to comment Share on other sites More sharing options...
Avalon Posted May 8, 2007 Report Share Posted May 8, 2007 I've just started on my Full Size Humbucker, got the bobbings and cores made, probably wind them tommorow with the new wire gauge (0.16) and to 16ohms per coil, if it works ok, its going to be installed on the test guitar for now and given an extended run. If all go's well, i'll post some pics and sound samples. Link to comment Share on other sites More sharing options...
onelastgoodbye Posted May 8, 2007 Report Share Posted May 8, 2007 Made some progress on zfrittz6's circuit...proper stripboard this time. the battery is just to give an idea of the size of the circuit. Link to comment Share on other sites More sharing options...
psw Posted May 8, 2007 Author Report Share Posted May 8, 2007 That's beautiful! Link to comment Share on other sites More sharing options...
zeppelinchld Posted May 9, 2007 Report Share Posted May 9, 2007 before we get to far away from the hex pickup idea again, Did any of u see the new strat in guitar player that has a roland hex pickup in it? Link to comment Share on other sites More sharing options...
col Posted May 9, 2007 Report Share Posted May 9, 2007 before we get to far away from the hex pickup idea again, Did any of u see the new strat in guitar player that has a roland hex pickup in it? Remember, for a hex pickup to be useful in this project, you need to build a hex driver. As Pete has explained building a working hex driver is a mighty difficult job, many times more difficult than building a standard single or dual core driver. Whats more it is debatable whether there is any advantage in having a hexophonic system. Don't forget that IF you did buy a hex pickup and build a working hex driver, for it to make sense, you would need hex circuitry: take one of the existing monophonic driver circuits, and multiply that by 6 !!!. Do you have room in your cavity ? Most people barely have room for a simple monophonic circuit. Col Link to comment Share on other sites More sharing options...
psw Posted May 9, 2007 Author Report Share Posted May 9, 2007 True..."Roland Ready Strat's" have been around for a while now. I hear that some of the early hex pickups were actually made from tape heads...maybe someone could work out how to use old cassette heads to DIY...kidding, probably not worth it.... Yes, making very small drivers are difficult, but the problems with EMI that we have also plague multiple drivers to some extent...there is significant cross talk between drivers in the hex system...even though I was running it from a monophonic source. The idea originally was to adjust for the different strings and responses in my hex designs, not so much for a truely polyphonic sustain...we did discuss such things though, but to make a sustainer that required a hexaphonic pickup system is probably asking a little too much... The exception could be something like the line 6 guitar which has no magnetic pickups...or some of the piezo saddle hex systems about (ghost, etc)...but that is a little too specialized I'd suggest... Meanwhile, having gotten some tools back, I have finally started to do a little construction (furniture) and getting my creative urges back...this is a good sign, but I still have not decided how I will approach my next sustainer build, with all these developments lately, I feel obliged to do something special. I really need to get a camera though to document it, so a while yet to go.... pete Link to comment Share on other sites More sharing options...
Ben Posted May 10, 2007 Report Share Posted May 10, 2007 (edited) I'm thinking about having a sustainer placed next to a tele neck pickup, as in my diagram, and using a 2nd tele neck pup cover to encase the sustainer (maybe I could use the cover to pot the thing?) - do you think the sustainer (probably a single coil one due to the restricted size) would work from beneath a tele neck-pickup cover? I would imagine it would, the only issue I could see here would be that the cover may force it further from the strings, meaning it would need to consume more power (maybe?) - do you think it would work with the limited magnetic field through it (which I'd guess would be about 1/2 the strength of if it were placed on top)? (The first diagram represents this situation) Or would I need a 2nd magnet to strengthen the magnetic field?- as in the 2nd diagram If you dont know I'll just have to test things for myself and find out, but it would be useful for pre-planning if anyone could offer any insight. Thanks Ben EDIT: forgot the image! Edited May 10, 2007 by Ben Link to comment Share on other sites More sharing options...
psw Posted May 10, 2007 Author Report Share Posted May 10, 2007 I'm thinking about having a sustainer placed next to a tele neck pickup, as in my diagram, and using a 2nd tele neck pup cover to encase the sustainer (maybe I could use the cover to pot the thing?) Hi Ben, good to see you back again... Would you believe I had thought a similar thing with the tele cover, most sustainers tend not to have a cover of any kind as it only serves to distance it further from the strings. The cover could also cause some other unexpected problems, but my hex designs were encased in an aluminium cover and worked ok, so who knows...as long as you have a very thin or no bobbin (as in tims jigamethingy shown above) it should work... - do you think it would work with the limited magnetic field through it (which I'd guess would be about 1/2 the strength of if it were placed on top)? No, I don't think that will work, certainly didn't from my experiments, the magnetisism needs to go through the core. You can run a magnetised driver next to your pickup though... If you dont know I'll just have to test things for myself and find out, but it would be useful for pre-planning if anyone could offer any insight. Unfortunately, you do need to test things out for your self, even if you have a goal like this in mind. I would suggest making a basic sustainer test setup at first, then trying to make something within the cover if all goes well... pete Link to comment Share on other sites More sharing options...
zeppelinchld Posted May 10, 2007 Report Share Posted May 10, 2007 im interested in making a new coil-less design and wanted to know if anyone knows how the lace sensor alumnitone pickups work? Link to comment Share on other sites More sharing options...
Ben Posted May 10, 2007 Report Share Posted May 10, 2007 Would you believe I had thought a similar thing with the tele cover, most sustainers tend not to have a cover of any kind as it only serves to distance it further from the strings. The cover could also cause some other unexpected problems, but my hex designs were encased in an aluminium cover and worked ok, so who knows...as long as you have a very thin or no bobbin (as in tims jigamethingy shown above) it should work... Cool. My last one had no bobbin and that was easy enough to make (still yet to finish the guitar in which it will be situated though ) - do you think it would work with the limited magnetic field through it (which I'd guess would be about 1/2 the strength of if it were placed on top)? No, I don't think that will work, certainly didn't from my experiments, the magnetisism needs to go through the core. You can run a magnetised driver next to your pickup though... I had a feeling it wouldn't. Ah well, no big deal- I'll just buy another magnet Thanks for the response and expect to hear from me in a couple of months Ben Link to comment Share on other sites More sharing options...
FlashBandit Posted May 11, 2007 Report Share Posted May 11, 2007 Sorry, I've been out of the loop a while. I just had an idea for potting, Why don't we wind the coils dry and then pot them in wax? It works for pickups, basically you just take an un-potted coil, and soak it in hot candle wax for like 10-20 minutes and the wax fills all the pores. You melt the wax by making a double boiler on the stove and the inner pot has your wax. Just afix the driver so it is covered by the wax, but not touching the metal sides. Take it out, let it dry, Any problems with that? Also, where do you get your magnets from? Can you magnetize any bar of steel? How much is a magnetizer? Link to comment Share on other sites More sharing options...
Primal Posted May 11, 2007 Report Share Posted May 11, 2007 FlashBandit, that is exactly how I pot my coils. The only downside is that, when winding by hand, the center windings may become loose. Still, for me its a LOT easier to wind it then pot it in wax for about 15 minutes. A tip: I use a double boiler, but my wax is actually in a mason jar. I just fill the top pot up with water and set the mason jar inside it. This prevents you from having to deal with a big chunk of wax in your pot after you are done. The only down side is that the coil MAY get hot enough to soften the wax allowing windings to shift, but I'm not entirely sure. Link to comment Share on other sites More sharing options...
FlashBandit Posted May 11, 2007 Report Share Posted May 11, 2007 (edited) I was planning on using regular candle wax, but then I realized that may melt on a hot day. Is there anything cheap, or common to add to the wax to raise its melting point? Have you ever gotten microphonics with wax potting? Also, I had a new core idea. Basically, you have a hole bunch of adjustable "pole" pieces that essentially act together as a bar style core. That way you can mechanically adjust the response of each of the strings instead of electronically. Here's a pic, tell me what you think. Also, any ideas for where to get the small rectangular pieces? I was thinking if they had squared nails like in the olden days... but any small rectangular piece of ferromagnetic metal should work. Edited May 11, 2007 by FlashBandit Link to comment Share on other sites More sharing options...
Avalon Posted May 11, 2007 Report Share Posted May 11, 2007 (edited) Did some tests last night with my Fullsize Humbucker, 2x16ohm coils, made with 0.16mm wire, side-by-side, wired in parallel, with opposite poles on the cores. It works well in standard mode, sustains all strings, bar about 3 frets, is as quiet as the Dual Rails, its less effective then the Dual Rail in Harmonic mode, but given the differences between both of the designs (16ohm coils instead of 13.5 on the dual rail, and the different spacing between the cores), i still think it works well. As for the wire guage (0.16 instead of 0.20), it does seem to change the balance abit, the G string in particular seems quite lively with the new guage, being nearly the first to start sustaining from its own faint sound (where as on my previous drivers it was always the thick E). As for the actual size of the coils, the 16ohm coils are about the same size as my 8 ohm coils with the 0.20 guage wire, 6mm wide including the 2mm core, which i think is pretty good (also bare in mine my 8ohm coils were built on 3mm cores). I think my next step is going to be another Dual Rail, 2x13.5ohm (with the 0.16 wire), wired in parallel, and see if i can make it my working test pickup, then move back to the circuit design (and probably try Cols circuit too). I think the Dual Rail 2x13.5ohm, Parallel design, is for now the best option, especially for a mid-driver position, which is my aim, and i think the circuit might be where some more of the secrets lie. Edited May 11, 2007 by Avalon Link to comment Share on other sites More sharing options...
col Posted May 11, 2007 Report Share Posted May 11, 2007 Did some tests last night with my Fullsize Humbucker, 2x16ohm coils, made with 0.16mm wire, side-by-side, wired in parallel, with opposite poles on the cores. It works well in standard mode, sustains all strings, bar about 3 frets, is as quiet as the Dual Rails, its less effective then the Dual Rail in Harmonic mode, but given the differences between both of the designs (16ohm coils instead of 13.5 on the dual rail, and the different spacing between the cores), i still think it works well. As for the wire guage (0.16 instead of 0.20), it does seem to change the balance abit, the G string in particular seems quite lively with the new guage, being nearly the first to start sustaining from its own faint sound (where as on my previous drivers it was always the thick E). As for the actual size of the coils, the 16ohm coils are about the same size as my 8 ohm coils with the 0.20 guage wire, 6mm wide including the 2mm core, which i think is pretty good (also bare in mine my 8ohm coils were built on 3mm cores). I think my next step is going to be another Dual Rail, 2x13.5ohm (with the 0.16 wire), wired in parallel, and see if i can make it my working test pickup, then move back to the circuit design (and probably try Cols circuit too). I think the Dual Rail 2x13.5ohm, Parallel design, is for now the best option, especially for a mid-driver position, which is my aim, and i think the circuit might be where some more of the secrets lie. Sounds good, but have you tried the original 2x 4ohm dual rail with coils wired in series (0.2 wire) - you can't say whats best if you've not tried that Link to comment Share on other sites More sharing options...
Avalon Posted May 11, 2007 Report Share Posted May 11, 2007 Did some tests last night with my Fullsize Humbucker, 2x16ohm coils, made with 0.16mm wire, side-by-side, wired in parallel, with opposite poles on the cores. It works well in standard mode, sustains all strings, bar about 3 frets, is as quiet as the Dual Rails, its less effective then the Dual Rail in Harmonic mode, but given the differences between both of the designs (16ohm coils instead of 13.5 on the dual rail, and the different spacing between the cores), i still think it works well. As for the wire guage (0.16 instead of 0.20), it does seem to change the balance abit, the G string in particular seems quite lively with the new guage, being nearly the first to start sustaining from its own faint sound (where as on my previous drivers it was always the thick E). As for the actual size of the coils, the 16ohm coils are about the same size as my 8 ohm coils with the 0.20 guage wire, 6mm wide including the 2mm core, which i think is pretty good (also bare in mine my 8ohm coils were built on 3mm cores). I think my next step is going to be another Dual Rail, 2x13.5ohm (with the 0.16 wire), wired in parallel, and see if i can make it my working test pickup, then move back to the circuit design (and probably try Cols circuit too). I think the Dual Rail 2x13.5ohm, Parallel design, is for now the best option, especially for a mid-driver position, which is my aim, and i think the circuit might be where some more of the secrets lie. Sounds good, but have you tried the original 2x 4ohm dual rail with coils wired in series (0.2 wire) - you can't say whats best if you've not tried that Well i tried it in Stacked HB form, and for the difference in noise it picks up compaired to parallel wired drivers (which i have tried in both stacked and dual rail), i think the dual rails wired in parallel are the best option, baring in mind that the Stacked and Dual Rail designs are very close in the amount of noise they pickup in my tests. The parallel designs are the only drivers that i've actual had working to an extent in the mid position, so im just following my test results really. Once i get my bobbingless winding jig made, it will take the work out of making the dual rails, then i can soon make a 2x4ohm dual rail for series, and give it a try, to rule it in or out of testing. But i think a couple of other ppl are making them atm, so maybe they'll have some info on those before i do. Link to comment Share on other sites More sharing options...
FlashBandit Posted May 11, 2007 Report Share Posted May 11, 2007 With all of our hard endeavors to make EMI cancel out, wouldn't it just be easier to shunt it to ground by wrapping the driver or each pickup with a foil thats connected to ground? Link to comment Share on other sites More sharing options...
Avalon Posted May 11, 2007 Report Share Posted May 11, 2007 Well i wouldn't mind some ideas on shielding too. Link to comment Share on other sites More sharing options...
col Posted May 11, 2007 Report Share Posted May 11, 2007 Sounds good, but have you tried the original 2x 4ohm dual rail with coils wired in series (0.2 wire) - you can't say whats best if you've not tried that Well i tried it in Stacked HB form, and for the difference in noise it picks up compaired to parallel wired drivers (which i have tried in both stacked and dual rail), i think the dual rails wired in parallel are the best option, baring in mind that the Stacked and Dual Rail designs are very close in the amount of noise they pickup in my tests. The parallel designs are the only drivers that i've actual had working to an extent in the mid position, so im just following my test results really. Once i get my bobbingless winding jig made, it will take the work out of making the dual rails, then i can soon make a 2x4ohm dual rail for series, and give it a try, to rule it in or out of testing. But i think a couple of other ppl are making them atm, so maybe they'll have some info on those before i do. Stacked humbucker format and dual rail series wired are not the same thing at all. As I've explained more than once, the stacked format involves some cancellation, not just of noise, but also of the signal itself - this does not happen with dual rail format. This means that stacked format is significantly (for our application) less efficient. Also note that EMI control that we want is not the same as humbucking action in a pickup - we're not trying to stop the driver picking up stray electrostatic noise, we are trying to reduce/control its output of electromagnetic radiation. I'm not saying that the parallel wired version is not better (remember it was me who first proposed it) just that we cannot say which is better until a thorough comparison has been performed . Comparing a stacked series driver with a side by side parallel driver doesn't really tell us if series or parallel are equivalent or if one is better than the other. cheers Col Link to comment Share on other sites More sharing options...
col Posted May 11, 2007 Report Share Posted May 11, 2007 (edited) With all of our hard endeavors to make EMI cancel out, wouldn't it just be easier to shunt it to ground by wrapping the driver or each pickup with a foil thats connected to ground? You can't shunt magnetic flux to ground ! The only way to 'shield' something from magnetic flux is to provide a 'flux conduit' an alternative route that the flux will prefer on its back to the opposite pole of the magnetic circuit. The problem for us is that we want the flux to escape - otherwise it won't get to the strings and make 'em shake. But we don't want the flux to get to the pickup... it's a tricky one So far the best approach we've found for controlling the flux has been to use a layout similar to a humbucker pickup... what this does is focus the flux in a much smaller area than happens with a single coil style driver - much less flux escapes horizontally towards the pickup, but there is still enough potruding up towards the strings.. (unfortunately there is also some protruding down into the guitar body, so its important to locate the control electronics carefully....) You can use metal 'shields' leaving only the top string-facing part open, but this has an effect on the efficiency and can reduce the level of flux reaching the strings, so the design of it is difficult to get right. Its possible to get some idea of whats going on with the flux by using an FEA application such as 'femm' to model simplified versions of the magnetic circuit.. heres an example that I did ages ago... showing two magnetic cores surrounded by a partial 'shield' EDIT: note the gaps along the bottom of the 'shield' - without these, the shield becomes more saturated, and the radiation at the top that we need to move the strings is reduced ! Take a look at the kinman pickups - he uses carefully designed 'shields' similar to this... you will notice that they are not solid, but have scalops, holes and gaps... these are not accidental or to look cool, or to use less metal, they are because it works best that way At the end of the day, femm style software can only help us a little, its only two dimentional, and does not include the active components like the coil and wiring... but it can be useful to help our understanding of what the flux does. The only really conclusive way to decide what works and what doesn't is to build stuff and test it Col Edited May 11, 2007 by col Link to comment Share on other sites More sharing options...
col Posted May 11, 2007 Report Share Posted May 11, 2007 Well i wouldn't mind some ideas on shielding too. here's one I made earlier: At the time I decided that it didn't help, although since then I have found other problems with the setup I was using at that time, so it may be worth taking another look at this sort of flux conduit 'shield'. Juán has reported good results using flux conduit shielding, and at least one of the commercial units does use a partial 'shield' Personally, I feel that the other ways of reducing EMI problems are still worth more time and effort than shielding... e.g. improving the driver design, maximising efficiency in the driver and circuit, reducing signal distortion to help mask background fizz etc. Link to comment Share on other sites More sharing options...
Avalon Posted May 11, 2007 Report Share Posted May 11, 2007 Sounds good, but have you tried the original 2x 4ohm dual rail with coils wired in series (0.2 wire) - you can't say whats best if you've not tried that Well i tried it in Stacked HB form, and for the difference in noise it picks up compaired to parallel wired drivers (which i have tried in both stacked and dual rail), i think the dual rails wired in parallel are the best option, baring in mind that the Stacked and Dual Rail designs are very close in the amount of noise they pickup in my tests. The parallel designs are the only drivers that i've actual had working to an extent in the mid position, so im just following my test results really. Once i get my bobbingless winding jig made, it will take the work out of making the dual rails, then i can soon make a 2x4ohm dual rail for series, and give it a try, to rule it in or out of testing. But i think a couple of other ppl are making them atm, so maybe they'll have some info on those before i do. Stacked humbucker format and dual rail series wired are not the same thing at all. As I've explained more than once, the stacked format involves some cancellation, not just of noise, but also of the signal itself - this does not happen with dual rail format. This means that stacked format is significantly (for our application) less efficient. Also note that EMI control that we want is not the same as humbucking action in a pickup - we're not trying to stop the driver picking up stray electrostatic noise, we are trying to reduce/control its output of electromagnetic radiation. I'm not saying that the parallel wired version is not better (remember it was me who first proposed it) just that we cannot say which is better until a thorough comparison has been performed . Comparing a stacked series driver with a side by side parallel driver doesn't really tell us if series or parallel are equivalent or if one is better than the other. cheers Col Im not compairing Stacked series to side-by-side parallel mate, im compairing the Stacked parallel to the side-by-side parallel. Both have a very similiar interfearence, relative to how close they get to the bridge pickup, at maximum power (before it picked up EMI from the bridge), and how much sustain was still present on the strings. The effectiveness of the stacked HB (or lack of effectiveness) is not in question, but the amount of EMI the Dual and Stacked attract, is very similiar in parallel wiring, so based on this, i think the Dual and the Stacked will attract similiar amounts of EMI wired in series (similiar amounts to each other, not to the parallel versions). Thats why i haven't built one yet, i've not writen anything off, im just going down the Dual Rail parallel route, based on what i've tested so far, its the most effective driver, its just my opinion though. Link to comment Share on other sites More sharing options...
col Posted May 11, 2007 Report Share Posted May 11, 2007 Im not compairing Stacked series to side-by-side parallel mate, im compairing the Stacked parallel to the side-by-side parallel. Both have a very similiar interfearence, relative to how close they get to the bridge pickup, at maximum power (before it picked up EMI from the bridge), and how much sustain was still present on the strings. The effectiveness of the stacked HB (or lack of effectiveness) is not in question, but the amount of EMI the Dual and Stacked attract, is very similiar in parallel wiring, so based on this, i think the Dual and the Stacked will attract similiar amounts of EMI wired in series (similiar amounts to each other, not to the parallel versions). Thats why i haven't built one yet, i've not writen anything off, im just going down the Dual Rail parallel route, based on what i've tested so far, its the most effective driver, its just my opinion though. Ah, sorry 'bout that, I misunderstood - seems like good reasoning - and thanks for putting the time and effort into these tests - Its great that the project is being moved on constantly. (btw, it's the EMI that they are producing that we're worried about rather than what they attract... but that's just a little detail that doesn't effect the validity of the tests at all ) I can't wait for someone to compare a side-by-side 2x4ohm series driver with a side-by-side 2x16ohm parallel one cheers Col Link to comment Share on other sites More sharing options...
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