Avalon Posted May 18, 2007 Report Share Posted May 18, 2007 Again, fantastic work, and a fantastic description of how you went about it, a few more observations and questions in the quote below... Strange, 'cause my G is very responsive in the lower frets, and even in normal mode, below the 7th fret, morphs to a harmonic over time (probably due to my 100uF output cap, treble bias mod to the circuit, and driving it hard with a powerful preamp, and the spiky single coil bridge pickup in the strat...) In standard mode, the G is excellent, and does morph to harmonics too, but in harmonic mode it seems to damp the string more then anything, but its only on the G, and i can work around it. Harmonic mode can be a little more inconsistant than normal. It works by dampening the fundumental frequencies and leaving the harmonic frequencies to be driven. This can mean that it lacks a little power in this mode and, because harmonic frequencies are faster and closer together, will be prone to problems at various points along the strings length due to the driver's position. It also may be associated with the pickups frequency response, better harmonic response may come by adjusting the bridge pickup closer to the strings overall, or problem strings like your G...could be worth experimenting with... Yes thats a very good point, for example, the pole peices on the bridge pickup (Dimarzio Evo) are adjusted quite abit to suit my tone and style, so it might be worth fiddling with them, the G might be backed off more then some of the others. So definately worth experimenting. Ahhh...so, we have tested a thinner guage wire with more turns in parrallel, nice one. You have them down to 2mm thick (like col's), how wide are they (do they completely fill the bobbin?) and roughly how many turns do you think. They are about 6mm wide (including the core) and don't even half fill the bobbin, and with the shallow height, i think it could easily have a pickup underneath, which is something i might come back to at a later date. They were about 130 turns for 16ohms, the next dual rails i try will only be 13.5ohms, so they should be even thinner (plus i'll be going back to 3mm high coils). So, are these wound with PVA wood glue type stuff like mine...what did you use for potting? Im potting them in PVA wood glue as i wind them, Speed Bond to be specific, which i used to build 2 guitars with, its not fast setting as such, like the name sugests, but its cures fully in about 48 hours, but touch dry in a few hours, and i've been using this bottle (112g) for 4 years now lol. It looks fantastic...a lot of your success is in part to your skill in the arts and crafts, top notch construction. A terrific description of how you did it to get a professional looking job, not like my long winded explanations that can intimidate people... Well you, this thread and all the other great people here are what got me inspired to start on this, and as i've mentioned previously, i wouldn't of had a clue where to begin without it, but now im starting to get into it, and electronics in general, which i've never really gone into much, other then wiring the inside of guitars up and stuff. So you've inspired me out of my arm chair Yes, very close pickups on these types of guitars may well be a problem, at least at this stage of development. The way things are going with the experimentation and implementing of ideas, who knows, perhaps it is possible... Certainly a mid driver is possible and holds many benefits...the main one being the simplified installation and wiring due to no longer needing to bypass the pickups...it would be just like installing on a single pickup guitar, once the mid pickup is removed and an alternate switching system is decided upon for the now two pickup guitar (that's what I'm looking at now...) I'm sure we'll all be pleased to see how you go with col's circuit. I am sure you could patch it in in front of the F/R circuit in place of the lm386 one, if you wanted to test it out on this guitar BTW. I think the mid driver is just a matter of construction, you look like the best candidate to make it happen in the short term. so go for it!!! Other than this, and the endless refinement of the device, I guess the remote box idea comes back as a possibility. One of the main problems with the box idea was that it required a lot of wires to and from the controls and the driver in installation. Most of this associated with the bypassing of other pickups. A mid driver or single pickup guitar removes this necessity and the box could provide some with the potential to try this without drilling holes for switches and providing space for circuitry and easy battery access...if it could be built as cool as some of Tim's designs (back in the page 30's), it could even be a preferable solution... Oh yes, and the bass sustainer, oh and the seven string sustainer, oh and the ultra small/thin surface mounted sustainer... pete Well i have everything i need to start on Cols circuit now (bar the lm386 side of the circuit), so that along with dual rails will be my focus for now, but im also going to be testing with another F/R circuit too, so i have plenty of options (and can test the drivers seperate to the new circuit if needed). A working Mid Driver would be excellent, but failing that, a neck driver with pickups incorperated might be a good second (although that probably has its issues aswell). So many options, and so little time Link to comment Share on other sites More sharing options...
col Posted May 18, 2007 Report Share Posted May 18, 2007 ...Well i have everything i need to start on Cols circuit now (bar the lm386 side of the circuit)... and of course up to date docs... so here goes... ======================= Schematic Layout diagram Notes: Some of the values on the layour do not match those on the schematic - I would be inclined to trust the ones on the schematic.... the changes were made as I was testing variations of the different harmonic modes. This process invloved simulating different values and then switching components on the circuit. The schem comes from the sim app, so the values will be more up to date - I found the layout app _really_ slow whith so many components, so was lazy about updating it. some component changes: R30 was 15k, now 27k )_ mixed mode 2 tweak C10 was 10nF now 22nF ) R29 was 18k, now 5k6 )- mixed mode 1 tweak addition of R31 (100k) - mixed mode1 If the modes don't have the response you like, you could try tweaking 1 or more of these components. ................. Changes from older circuit: Deciding to use a seperate on/off switch allowed me to go for a 3P4T rotary instead of a 2P5T, this meant I could change mixed mode 1 to use a high pass filter. It still doesn't work as well as I would like, but is better than before. If this was to be a 'product' I would consider simplifying be possibly using only normal and mixed mode 2 (with maybe full harmonic as well). So if you can't find a 3P4T rotary switch, this would be an option ..................... The connections: all the holes on the layout diargram that need wires attached are marked. in, out, +9v and gnd are all pretty obvious. (+4.5v is just for reference - no wire needed here) the rest - a1, a2, b1, c1, c2, d, e, e1, e2, x & y are related to poles of mode switch e is the output from the input buffer/amp d is the input to the mode op-amp the mode connections are as follows: normal e connected to a1 d connected to a2 x connected to e mixed 1 e connected to c2 d connected to c1 x connected to y mixed 2 e connected to e2 d connected to e1 x connected to e full harmonic e no connection (other than to x) d connected to b1 x connected to e ...................... As you can see, the switch wiring is pretty complicated and ends up with a big nest of wires... make sure that each wire is as long as needed for easy installation, but no longer. Might be good to colour code the wires as well... I used 2 colours, 1 for the 'sends' one for the 'returns' but just do what makes sense. Something else that is worth doing is working with the schematic and layout, pencilling in the component numbers onto the schem... this will help you relate the schematic to the layout, and also will aid in double-checking and debugging Use your meter to double check that each mode switch position makes the connections described above, and only those. Another thing to watch out for is that you have all the 'track cuts' in place - the layout creator app transparency is difficult sometimes, and the track cuts can be quite well hidden e.g. 2 under R19, 1 under R15 etc. make sure you have exactly 40 of them, if not study the layout diagram some more. Anyhow, thats it :-) If you have any questions or spot eny errors, don't hesitate. Col Link to comment Share on other sites More sharing options...
col Posted May 19, 2007 Report Share Posted May 19, 2007 Avalon, Just in case I misunderstood, and you were implying that you needed a diagram for the power stage, I dug this up Afaict, this is the power stage I used along with my most recent agc circuit... my one has a few extra caps that I hacked on to try and cure an issue with an earlier agc attempt, but this should be fine 'as is' Col Link to comment Share on other sites More sharing options...
Paul Marossy Posted May 19, 2007 Report Share Posted May 19, 2007 Hey, thanks for posting the guts of the Ebow. I've been very curious as to how it was done in such a small space! Link to comment Share on other sites More sharing options...
psw Posted May 19, 2007 Author Report Share Posted May 19, 2007 Hi Paul, I've seen your posts at the other forum...Ebow thread at Aron's SBF...if you are building one, please share over here too... There have been various ebow posts on here and a few more dedicated threads in this section (use the search function to find them and then to other links)... The ebow is very simple but most consider the "design package" the real masterstroke of the design. This requires a suitable casing and the ebow has a great ergonomic design. I have considered making something. For instance, my hex design tecnology could be used to create something even smaller, but by far the biggest component is the battery. Building something that contains the components and the power source, even with a miniturized driver/pickup, still ends up being similar in size...making something ergonomic, you get a similar shape...the sign of a very successful design. The only other thing people have proposed is a smaller device that could sit in a docking station on the guitar...the problem here of course, is that you would need wires to drive it that would probably get in the way, and the thing could be too small to actually use effectively...remember it has to be close to the strings and guided above it by the strings either side of it... I know this thread is huge, but somewhere, someone posted an actual ebow destroyed showing what was left of the coils and the circuitry (the whole thing is set in epoxy making the case)...as I recall the real thing has some sheilding around the driver and pickup coils...worth checking out if you can find it. Otherwise, the ebow is a simple device in concept and with an appropriate pickup coil does not require preamps and such so the circuit is very simple. A reverse switch on the driver will give you the harmonic function too! -------- Thanks for updating your circuit col and adding the power module. This is important as you can see how people can be led astray by prototype circuits in progress by Tim's recent experience with Juan's work. I had also been concerned that people may think you preamp circuit is all there is to it, you still need the poweramp after it. -------- I am still building furniture and going through boxes and boxes of stuff...gradually the electronics stuff and loose components are coming to the surface. I have found a couple of the kits I modified for my guitar and plenty of driver wire... I am still not entirely sure how I will proceed with my guitar...I guess the first step is to rewire it into an effective two pickup guitar in preparation for a mid driver. I am still a little loathe to cut into it or drill holes I may regret later, plus it has no pickguard to cover any mistakes...hmmm This brings forward the idea of an outboard box type of thing. Such a scheme really opens up the circuitry thing as you could include the battery and circuit without the restrictions imposed by the control cavity... I have also found my mini push/push illuminated and latching 4PDT switches which could be cool to incorporate. Cheaper than toggles too! ------- Anyway, still a spectator for now, but getting closer to getting the iron out! pete Link to comment Share on other sites More sharing options...
Paul Marossy Posted May 20, 2007 Report Share Posted May 20, 2007 (edited) Hi psw! You are becoming a person of notariety around here these days! I'm not really trying to build an Ebow, I'm just rounding up info on it to see how it works, how it's constructed and stuff like that. The circuitry is the easy part, that is DIY-able - some people have made a working circuit. The housing for the circuit is another story entirely... I got an actual Ebow about a week ago and I'm really enjoying it (after playing guitar for nearly 20 years now). And, of course, my engineering mind wants to know all the ins and outs of it. Edited May 20, 2007 by Paul Marossy Link to comment Share on other sites More sharing options...
Avalon Posted May 20, 2007 Report Share Posted May 20, 2007 Avalon, Just in case I misunderstood, and you were implying that you needed a diagram for the power stage, I dug this up Afaict, this is the power stage I used along with my most recent agc circuit... my one has a few extra caps that I hacked on to try and cure an issue with an earlier agc attempt, but this should be fine 'as is' Col Thanks Col for the updated info & Schematics, its appreciated Hopefully by the end of the week, i'll have this built, plus a new & improved Dual Rail to test with it, time permitting anyway, i'll let you know how it go's as and when it does Thanks again mate Link to comment Share on other sites More sharing options...
tubab0y Posted May 21, 2007 Report Share Posted May 21, 2007 would the guitar output just be from the pickup at the same place as the sustainer in? almost done with mine! Link to comment Share on other sites More sharing options...
psw Posted May 21, 2007 Author Report Share Posted May 21, 2007 would the guitar output just be from the pickup at the same place as the sustainer in? That's how mine is done, the bridge pickup is wired to the circuit and on to the selector and/or controls...it is hard wired, the bypass switch turns on the bridge pickup should another pickup be selected, turns on power for the circuit and disconnects the neck and middle pickup. This switch can take a bit of nutting out, of course, with a single pickup guitar you just need to turn the power to the circuit on! Similarly, with the mid-driver idea, you wouldn't need bypassing and could use both or either pickup to drive the thing (connected after the selector) and again would simply be a matter of turning on the power...simple. This is the major attraction for me of the concept and opens up other doors too... almost done with mine! fantastic, keep us posted... pete Link to comment Share on other sites More sharing options...
Redhat Posted May 22, 2007 Report Share Posted May 22, 2007 (edited) I was wondering if anyone has tried different shapes for the coil? I was thinking something like this: http://docs.google.com/Doc?id=d4h53kp_4cspr78 My thinking is to be able to adjust the driver for specific strings. Any thoughts? By the way, the red lines are just bobbin locations, the idea being to wind a pickup underneath. Edited May 22, 2007 by Redhat Link to comment Share on other sites More sharing options...
Primal Posted May 22, 2007 Report Share Posted May 22, 2007 So, I had an idea for a driver design. I'm not sure if anyone has though of this yet. Its sort of a hybrid between the standard humbucker design and a coil on its side (like the Q-tuner pickups). Here it is: I have absolutely NO idea of such a design would work as I imagine it in my head. Anyone with more knowledge care to comment? Please excuse the HORRIBLE artwork. Link to comment Share on other sites More sharing options...
zeppelinchld Posted May 22, 2007 Report Share Posted May 22, 2007 primal, that looks pretty cool, but would the EMI still not interfere with the bridge? u should make a prototype and try it out. Link to comment Share on other sites More sharing options...
Primal Posted May 22, 2007 Report Share Posted May 22, 2007 I would prototype it, but I don't have a working circuit, and I can't make the bobbins for whatever reason (they always fall apart on me, haha). The EMI would still interfere, but my thinking is that, since the two coils are at a 90ish degree angle to each other, the 45 degree angle in respect to the bridge pickup would mean that much of the EMI would go down into the body, under the pickup. Link to comment Share on other sites More sharing options...
onelastgoodbye Posted May 23, 2007 Report Share Posted May 23, 2007 @ Primal: since the coils are angled, they also put out less magnetic force straight at the strings; so you'll have to use more power, which in turn causes more emi. I did some tests with coils on their side and though it works, the performance was not good enough (worse than the regular rail) to justify the more complicated construction. @Thruth_David and Zfrittz6: thanks for the diagram, I'll try that, but it 'll have to wait for a couple of weeks.. Tim Link to comment Share on other sites More sharing options...
donbenjy Posted May 24, 2007 Report Share Posted May 24, 2007 hey, not been here for a while now! Sorry if there's already been a big discussion about this but wading through 180 pages is gonna take some time! anyway, I'm interested in modding my humbucker sized P90 into a sustainer (but retaining the original function of the pickup too.) in my Strat (p90 + motherbucker pickups with very custom wiring!) I've not had a look inside for a while (though I did build the guitar myself, so I do know what I'm doing!) but I'm pretty sure that I can deconstruct the pickup all right...I have a few questions though...If they've already been asked, just point me in the right direction! Ok, I do A Level Physics, so I get the concept of the sustainer/driver, but the actual construction is more tricky: I asked here ages ago about the P90 idea, and I'm sure that someone said that it'd been done before, but I'm unsure where I'd actually put the driver: would there be space inside the housing to mount the driver below the pickup windings (using the P90's magnet/pole pieces), or would it have to be closer to the strings? I wouldn't have thought so, because the pole pieces are close enough, but you never know! Would it be feasible to insulate the pickup widing with tape, and wind the driver coils over the current windings? I know this isn't the best idea because it would essentially mean that I couldn't remove it easily, especially if I used glue to "pot" it! would I need to add another magnet/core, or would the current pole pieces and magnet suffice? here's my current flow diagram: ATM I have the Motherbucker wired as-is with the killswitch and 5 way switch, and the P90 going direct to a blend pot, then master volume... My other thought was to possibly build a simple driver using the tthread in the tutorials section as a basis, and mounting it under the pickguard in the middle position, as I've heard that they still work well there...will the driver function well under 1/4" of plastic?! I don't mind cosmetically changing the guitar, but if the P90 is impossible to mod, then I'd rather not lose a pickup (though I might have to!) I've also been talking to the band about it, and our bassist seems quite interested in a bass version: any modifications needed for a bass sustainer, like adding more windings or stronger magnets? Cheers This is an awesome thread btw! Link to comment Share on other sites More sharing options...
mrjstudios Posted May 24, 2007 Report Share Posted May 24, 2007 Nice work Avalon! That looks really good -- and from what you say, it sounds like "it sounds good too." -Once the paint job on my guitar is finished and the thing re-assembled, I'll get to finishing my 2nd "sustainer guitar." But for now I just need to get the #1 guitar done so I have something to play.... Sheesh, in the matter 2 months my single coil driver looks like a dinosaur -- but hey, the rate of progress is a good thing. Link to comment Share on other sites More sharing options...
psw Posted May 24, 2007 Author Report Share Posted May 24, 2007 This is an awesome thread btw! Thanks, and welcome back... Still got a few problems there I'm afraid... where I'd actually put the driver: would there be space inside the housing to mount the driver below the pickup windings (using the P90's magnet/pole pieces), or would it have to be closer to the strings? No...it will have to go on top, the driver coil needs to be as close to the strings as possible (yes I tried it!)...sustainiac and fernandes wont even work with a cover on it... Would it be feasible to insulate the pickup widing with tape, and wind the driver coils over the current windings? I know this isn't the best idea because it would essentially mean that I couldn't remove it easily, especially if I used glue to "pot" it! No...this does not work (yes I tried itx2)...once modified, the pickup will stay modified, but the coil will need to be stacked on top of the coil of the pickup and the pickup adjusted as close to the strings as possible... would I need to add another magnet/core, or would the current pole pieces and magnet suffice? If the driver coil is stacked on top like mine, it can share the pickup's core....but if the driver is completely separate, it will need it's own magnet source... My other thought was to possibly build a simple driver using the tthread in the tutorials section as a basis, and mounting it under the pickguard in the middle position, as I've heard that they still work well there...will the driver function well under 1/4" of plastic?! I don't mind cosmetically changing the guitar, but if the P90 is impossible to mod, then I'd rather not lose a pickup (though I might have to!) Two things... 1. The mid driver is a goal of this thread and is definitely possible, but it will not be a "simple driver"...it will need at least two coils similar to the work avalon has been doing recently...a P90 (being a single coil) would not be possible to mod in this way and a specialised driver would be required...stay tuned for further developments from Mr A and myself on the mid driver... 2. As above, the coil needs to be as close as possible to the strings and that means no hiding it under scratchplates and the like...sorry... here's my current flow diagram: OK...well there are a few problems here. You have a three pickup guitar like my strat and so the wiring is complicated and some comprimises may need to be made (depending on the switching). You need to completely bypass all but the bridge pickup, select the bridge pickup and turn on the power. I used a 4PDT switch, but to retain your wiring, you may even need more. In your scheme, only the middle pickup is turned off, but not completely bypassed (both ends of the coil)... I've also been talking to the band about it, and our bassist seems quite interested in a bass version: any modifications needed for a bass sustainer, like adding more windings or stronger magnets? Actually, it is much easier to drive bass strings and often there is enough space on the surface of the bass to fit the driver without modifications. Also, the longer scale length means there may well be enough distance betweeen the pickup and the driver so that bypassing will not be necessary... I tried it with my bass with mixed results. I used the "sustain box" (a copy of my strats driver and circuit) but my fretless bass has a single split P-bass pickup in it. Plenty of room to mount it on the body and well away from the pickup and it did drive the strings fairly powerfully. The problems are, with this type of pickup, 2 strings are in reverse phase with the other so you would need a driver of similar construction to marry with this set up. Also, the circuit has a treble bias that suited the higher strings a lot more...I'd be going for a much bigger output capacitor for the bass (say 470uF) to drive the lower frequencies... As always...I would suggest that you make the circuit and a simple driver and test the device before you get to switching and such on your actual guitar. The harmonic function and power can be operated simple by switching the wires around or flipping the magnet of the driver over and you can test it over the neck, well away from the pickups. Once you have got to this stage, then think about modifications to pickups and the problems of installation... Hope all that helps... pete Link to comment Share on other sites More sharing options...
psw Posted May 24, 2007 Author Report Share Posted May 24, 2007 Nice work Avalon! Sheesh, in the matter 2 months my single coil driver looks like a dinosaur -- but hey, the rate of progress is a good thing. Yeah...I really need to get on to doing my next version myself...I have plans, but Avalon is really doing a lot af fantastic groundwork... There is still a lot of merit in the simple single coil driver and pickup mod and it will work well for most...it's a good place to start... One of the good things abouit this project is that you can update the thing as developments occur...a dual coil driver will use all the same circuitry and installation for instance...or you could add on something like Col's compression circuit and increased modes... I'm still thinking about how I want to proceed before I start messing with a perfectly good guitar! How do I want to convert it to a two pickup guitar, where will I put controls, how will I find room in the tiny control cavity... I'm anticipating a new circuit design (no more lm386!) and compact preamp and a mid driver, probably of a rail design...following the latest trend. I have a thought that the coils could be made a little thicker (3-4mm) and the blades closer together allowing space for 3mm steel shields on either side of these to help restrict EMI...but as always...experimentation is the key...I will be watching Avalon's work very closely as a guide to how well these things can be built as it seems that the physical construction seems to be very important to the success of these things... pete Link to comment Share on other sites More sharing options...
mrjstudios Posted May 24, 2007 Report Share Posted May 24, 2007 I'm anticipating a new circuit design (no more lm386!) and compact preamp and a mid driver, probably of a rail design...following the latest trend. I have a thought that the coils could be made a little thicker (3-4mm) and the blades closer together allowing space for 3mm steel shields on either side of these to help restrict EMI...but as always...experimentation is the key...I will be watching Avalon's work very closely as a guide to how well these things can be built as it seems that the physical construction seems to be very important to the success of these things... pete Yes, I was thinking of building a 4ohm x 2 wired in series dual driver -- and it looks like I'm on the same page as the new stuff, well, sort of. I have already experimented with coil thickness -- my single coil driver (pictures posted previously) has about a 4-5mm thickness, and the core is made of a 3mm thick piece of steel bar stock. I also used a heavier wire gauge of 30AWG instead of the previously standard 32AWG (or even thinner more recently) that is a beefy military spec version magnet wire. I have even done some preliminary experiments using steel/aluminum to try shielding the thing. All of these things seem to be coming into question now, so I would be glad to answer any questions to save some experimenting time so you guys can focus on the dual-coil specific problems... -MRJ STUDIOS Link to comment Share on other sites More sharing options...
donbenjy Posted May 25, 2007 Report Share Posted May 25, 2007 where I'd actually put the driver: would there be space inside the housing to mount the driver below the pickup windings (using the P90's magnet/pole pieces), or would it have to be closer to the strings? No...it will have to go on top, the driver coil needs to be as close to the strings as possible (yes I tried it!)...sustainiac and fernandes wont even work with a cover on it... Ok...then is there likely to be space inside to accomodate the driver coil? I guess the best thing to do is to open it to have a look, but I wanna get a working prototype of the fetzer-ruby (that's still the current circuit that everyone uses right?!) before I bother opening my guitar - I'm still actively gigging with it as my backup/slide guitar, so I wanna keep the funtionality of two pickups for the most that I can! My other thought was to possibly build a simple driver using the tthread in the tutorials section as a basis, and mounting it under the pickguard in the middle position, as I've heard that they still work well there...will the driver function well under 1/4" of plastic?! I don't mind cosmetically changing the guitar, but if the P90 is impossible to mod, then I'd rather not lose a pickup (though I might have to!) Two things... 1. The mid driver is a goal of this thread and is definitely possible, but it will not be a "simple driver"...it will need at least two coils similar to the work avalon has been doing recently...a P90 (being a single coil) would not be possible to mod in this way and a specialised driver would be required...stay tuned for further developments from Mr A and myself on the mid driver... 2. As above, the coil needs to be as close as possible to the strings and that means no hiding it under scratchplates and the like...sorry... Yeah, I'd only use a mid driver if the P90 as too hard to mod effectively, and so I'd build my own anyway! Bearing in mind that I'm trying to be as cost effective as possible here, would it be better to just work at this instead of the P90? I'm quite happy to help with any ideas! here's my current flow diagram: OK...well there are a few problems here. You have a three pickup guitar like my strat and so the wiring is complicated and some comprimises may need to be made (depending on the switching). You need to completely bypass all but the bridge pickup, select the bridge pickup and turn on the power. I used a 4PDT switch, but to retain your wiring, you may even need more. In your scheme, only the middle pickup is turned off, but not completely bypassed (both ends of the coil)... Sorry - I didn't make that too clear; I've only got the P90 and motherbucker installed, no 3rd pickup. The 5 way switch is purely a coil tap on the motherbucker to bring out some different sounds! By using an on/off/on switch for the P90 pickup and sustainer combined, it ensures that you can't have the pickup and the sustainer on at the same time The only pickup left is the motherbucker, which I have a killswitch for already...I was thinking that this would provide some interesting sounds combined with the sustainer (though atm it shorts hot to ground, so I'm wondering whether this would aversely affect the driver, as the idea would be to have the sustainer constantly sustaining even if the motherbucker was off! I probably need another look at that!). I was considering a 4PDT switch, but would have prefered it if I could have P90 (pickup mode)/sustainer (fundamental mode)/sustainer (harmonic mode) with the extra poles to turn the power on and off, but I can only find on/on or on/off/on switches...anyone found a 4PDT on/on/on? I've also been talking to the band about it, and our bassist seems quite interested in a bass version: any modifications needed for a bass sustainer, like adding more windings or stronger magnets? Actually, it is much easier to drive bass strings and often there is enough space on the surface of the bass to fit the driver without modifications. Also, the longer scale length means there may well be enough distance betweeen the pickup and the driver so that bypassing will not be necessary... I tried it with my bass with mixed results. I used the "sustain box" (a copy of my strats driver and circuit) but my fretless bass has a single split P-bass pickup in it. Plenty of room to mount it on the body and well away from the pickup and it did drive the strings fairly powerfully. The problems are, with this type of pickup, 2 strings are in reverse phase with the other so you would need a driver of similar construction to marry with this set up. Also, the circuit has a treble bias that suited the higher strings a lot more...I'd be going for a much bigger output capacitor for the bass (say 470uF) to drive the lower frequencies... As always...I would suggest that you make the circuit and a simple driver and test the device before you get to switching and such on your actual guitar. The harmonic function and power can be operated simple by switching the wires around or flipping the magnet of the driver over and you can test it over the neck, well away from the pickups. Once you have got to this stage, then think about modifications to pickups and the problems of installation... Hope all that helps... pete Yeah...that could be a problem! I'm not gonna be roped into building it for him though! He might even be happy with just the treble side strings...and if that worked, he could easily build a clone and reverse the phasing on them! Thanks alot! I think the first step is to build the amp circuit, and then I should have enough wire to make a simple prototype anyway as well as the P90...What I may do, is install a basic driver in place of the P90 while I work on that, then at least some of it will work! Not quite sure how I'd mount a single-coil sized driver in a HB sized hole, but I'll do it somehow! as for parts for a simple driver: best type of magnets? and do I just use an iron core from a pickup or something? Cheers again! Ben Link to comment Share on other sites More sharing options...
donbenjy Posted May 25, 2007 Report Share Posted May 25, 2007 (edited) Ah, sorry for the double post: I'm working on the wiring diagram for the actual guitar, and I've kinda run into a problem - it's one of those complicated switching ones Ok, so I thought the best way to switch between pickups would be one switch for each pickup, as this allows me to keep my killswitch in the guitar (by turning one pickup off and toggling the other on and off). This dual switch idea is also kinda useful because I can simultaneously turn the neck pickup off, and the sustainer on with one switch (on/off/on) - that means I'll never be able to turn both on at once The problem is that I can't work out how to wire in the motherbucker - my current killswitch is just a simple on/on/on switch wired in parellel across the jack. In the middle position, ground and hot are shorted together, thus grounding the entire circuit. I did it this way because: A) it's the only way that I could find to have the guitar switching on/off/on, which is good because if wired the other way (off/on/off like most that I've seen) I risk flicking it when playing! It's completely silent C) It doesn't mess with the rest of the wiring in the guitar. I can't do this with the motherbucker as it will short out the hot signal which feeds the sustainer, and I have a feeling that this will sound abit crap (I'm assuming that the driver takes a small amount of time to "warm up" to get te strings vibrating properly) and cause a kind of psuedo-tremolo effect as the strings are alternately being driven and then not. This would also short out the P90, so It'd be impossible to turn the motherbucker off and use the P90 on it's own. [novice] If I was switching at a certain frequency I may end up engaging the driver out of phase and virtually stopping the string dead/potentially weakening it (though, if the signal is controlled by the pickup, I dunno if it's possible to engage it out of phase as they'd be "forced" into phase...?) [/novice] That's kinda wordy, but basically I'm trying to say that with the input of the F/R grounded, then the killswitch kills the sustainer as well...what I wanted was to have the sustainer continually on, but be able to toggle the signal to the amp on and off. So then I thought "why make it complicated?!" and considered just killing the motherbucker's hot path using an SPST, but that results in horrendous hum as the hot to the amp is left "failing" unless the P90 is turned on! Sooooo, what I'm asking is does anyone have any idea how I can have neck and bridge pickups seperately switched in and out without humming badly when both are "off?" Sorry if thats unclear! my head hurts! edit: went for a 3p4t rotary to do P90 pickup/Sustainer on/both Off and to change to way that the motherbucker off works in each position! Can't really explain it very well, but basically, with the P90 active, turning off the MB just cuts it's signal running to the pot. When the P90 is inactive, then turning off the MB breaks the hot connection to the jack, and runs it to ground. As the switching is wired in series, the motherbucker's hot lead is still active, and can continue driving the sustainer, just killing the audio signal to the amp. When the P90 is turned on and the switch is used, the hot signal is routed directly to the pot. If anyone cares, I'll do a diagram later! I just ran into another hiccup though...the retards at maplins took about 40 minutes to go through the Bill of Parts for my F/R, and still managed to leave out the 100nF cap pulling pin 7 of the LM386 to ground! What happens if I leave it out?! The only spare caps I have in the house are 10uF electrolytics! unless I buther some old radio or somethin?! Edited May 26, 2007 by donbenjy Link to comment Share on other sites More sharing options...
donbenjy Posted May 26, 2007 Report Share Posted May 26, 2007 Sorry sorry sorry for the triple post! maplins didn't have any of the transistors and so stuck in a 2N5401 which is a PNP...I tried it anyway, but it didn't work (that doesn't mean that the circuit is correct otherwise though!!!) If I turn the voltage on the collector up I get some really nice feedback effect that I can tune with the gain and volume pots, but then one of the pots started smoking so I turned it down alot! I really hope that it's just the transistor thats wrong though...I managed to find a 100nF orange drop cap in a radio that I was nicking the core from the LW reciever from so pin 7 is properly tied to ground now...I'm trying to find an alternative tranny on the radio (/CD/tape) circuit boards...there's tons of components, but I don't really think that comparing the datasheets of the models is gonna help seeing as I know nothing about transistors really! Anyway, if there is a chance of a similar audio style transistor in the radio/cd/tape player, what am I looking for? What specifically (in terms of maximum voltage or whatver) makes the 3 transistors on the schematic so suitible? and what do I look at on the datasheets that will provide similar results?! eeep! sorry for boring everyone with this! on the plus side, I have all the orange drops that I'll need I think, and a really nice core for my driver! Link to comment Share on other sites More sharing options...
Avalon Posted May 27, 2007 Report Share Posted May 27, 2007 Well alot of transitors have different pin arrangements, so i would get a data sheet on that 2n and find the pins, i believe the 2n's are Source, Gate, Drain, left to right as you look at the flat side, where as my MPF102 is Drain, Source, Gate, Left to Right. But even if the pins are right, i don't know if it will work im afraid. A couple of pages back Col put up some links for places that sell the J201's, they might also sell the alternatives too, i would definately try to get one of them if pos. Link to comment Share on other sites More sharing options...
donbenjy Posted May 27, 2007 Report Share Posted May 27, 2007 yeah, I tried it, and it was squealing (abit like a feddback loop on a fuzz pedal) so I pulled the transistor out of the breadboard to try and stop it, and there was zero change in the sound! I checked the pinout first, and that was ok, but I think the problem is that it is a bipolar PNP, and those ont he schematic are all N type FETs (I don't actually know the difference between using a bipolar or FET, but obviously there is one!)...I can't find any FETs at all in anything that I could just prototype with, so I'll have to wait and order one off somewhere! I looked at Rapid electronics yesterday: 10p for the transistor, £4.50 for postage!!! :S I think in the mean time I'll try and get on with winding the driver, even though I can't test it! I also had a look inside my strat, and the P90 seems to be sealed :S there are two really small screws inbetween the pole pieces on the bottom, but the base is welded/soldered to the sides in a big blob, so it suggests that I can't open it!!! I'll post a pic later! Hopefully I can fit the driver on top of the pickup then as a compromise! Link to comment Share on other sites More sharing options...
Avalon Posted May 27, 2007 Report Share Posted May 27, 2007 Thats where im abit luckier, i have a little electronic shop down the road from me that sells most things other then IC's and J-FET's, although they do stock alot of 2n's/BC's and fortunately for me the MPF102's, otherwise i'd be in the same position you are. I would order about 10 of them to make it worth well (and see if they have anything else useful while you're looking), £5 is alot for postage so you might aswell get your moneys worth out of it. Best of luck with the driver in the meantime though Link to comment Share on other sites More sharing options...
Recommended Posts