psw Posted March 13, 2006 Author Report Share Posted March 13, 2006 haha...no no...i mean solder the wires onto the driver...by normal, I mean no need to use sheilded cable...and twist them all along their length. This is known as a twisted pair. You can see the twisting here. One of the problems also is that the driver wires should be as short as possible. The longer the wires the more energy is lost and EMI generated. On my guitar the circuit is right down the back of the guitar...I have envisaged a circuit so small it could fit with the driver in the driver. With remote electronic switching, this could even be built into the side of the device or where ever. So simply twist them and keep them relatively short and clear of pickups and other signal wires, as far as possible... pete Link to comment Share on other sites More sharing options...
starry_night Posted March 14, 2006 Report Share Posted March 14, 2006 So simply twist them and keep them relatively short and clear of pickups and other signal wires, as far as possible... pete whoa! that nearly made me wrong after all! you see i am trying to rebuild my hum so it seems impossible to keep the driver away from the neck pickup... good thing i wired the driver on the other side (the pickup exits on the upper side of the guitar and the driver is on the downside)... now the problem is, i cant troubleshoot why the signal slowly increase its volume when i activate the sustainer.. i mean it would start very low then constantly increases.. i think the signal is sent too slow or something is keeping it from flowing smoothly... the 'pop' is kinda loud but the starting sustain is very low.. and i cant work on the harmonic switch.. it wont give the harmonics... like the switch is useless after all.. i followed your dpdt diagram perfectly but it wont work.. i think the problem is not on the switch.. Theres a preamp pedal called the "Behringer PB100 Preamp Booster pedal", could I gut it and stick its innards into my guitar, and use that to drive the sustainer that I want to build? Thanks. actually ben ive been planning to take the 'innards' of my marshall mini-amp if ever i fail to build my fetzer-ruby but i have to come up with something to further 'boost' the mini-amp(put a boost like fetzer just before the mini-amp) to make it work better.... i hope this gives you the idea... Link to comment Share on other sites More sharing options...
psw Posted March 15, 2006 Author Report Share Posted March 15, 2006 OK...starry...I don't know quite what you are up to so far.... you see i am trying to rebuild my hum so it seems impossible to keep the driver away from the neck pickup... Well...obvoiusly...my driver is actually on top of the pickup like a stack so it's even closer to it than yours, as far as possible is what I mean. Also, when the driver is on all the other wires, especially the neck pickup are completely disconnected (hot and earth)...the bridge pickup is therefore the greatest concern, but even that will have to join in the circuit at some point. Sustainiac recommend the same precautions. now the problem is, i cant troubleshoot why the signal slowly increase its volume when i activate the sustainer.. i mean it would start very low then constantly increases.. Now...how do you mean the signal, how can you tell. Do you mean you have built the driver and it sustains but takes a while to respond? Have you tested the circuit with a speaker to make sure that you are getting a sound out of it? the 'pop' is kinda loud but the starting sustain is very low.. There is only a problem with "pop" on turning off...is that what you mean?? and i cant work on the harmonic switch.. it wont give the harmonics... like the switch is useless after all.. i followed your dpdt diagram perfectly but it wont work.. i think the problem is not on the switch.. No it is likely the driver...again you should check the circuit with a speaker...there should be no audible difference with the harmonic switch. It is much harder to drive harmonics and some of them will be very high. What it is actually trying to do is stop the string vibrating at the fundumental...it is working in reverse. Another thing, if I turn down the tone or use a bassy amp setting I wont get the harmonics...they are there but are being filtered out...try turning up the treble. But this problem and high string response all point to a problem with the driver. actually ben ive been planning to take the 'innards' of my marshall mini-amp if ever i fail to build my fetzer-ruby but i have to come up with something to further 'boost' the mini-amp(put a boost like fetzer just before the mini-amp) to make it work better.... Yes, this kind of practice amp may work fine...I guess they have some kind of preamp in them, not sure and may work as is...typically they simply use a LM386 anyway. What I think you have done is built a driver on half a humbucker...is that right? But I don't know how you did it. Did you block up the lower half as previously discussed on this idea leaving only about 3mm in the top section? Did you use the correct wire. What resistance is it? How close is it to the strings (it needs to be very close) likewise the bridge pickup? Is the neck pickup disconnected completely when operating or just de-selected (i had to disconnect both hot and ground)? How strong is the pickups magnet under the driver? Have you properly potted the coil, is it tight and secure, what have you potted it with? Are you getting sustain at all...on all strings or just the bass strings? Most importantly, what are you using to drive the thing if not the fetzer/ruby or the practice am...and what kind of signal is it sending, distorted clean, compressed, hot, treblely? How much power are you putting out. In short...perhaps a pic or drawing of what you are or am attempting to do would help. Typically, I would suggest you do the thing in stages...make a driver, make a circuit, test the driver and circuit, then build perhaps a driver on a pickup even better, then install and work out bypass switching. Your difficulties do seem to be related to the driver on the face of it, but it could be the signal characteristics too...it may even be some cancellation from the new design. Right next to your driver of one polarity in a humbucker is a pickup coil of a different polarity. As I have said, this whole thing has not been fully tested at all. The closest that I am familiar to it was my use of the "sustain box" on my Les Paul. This is a testing device. It did not bypass the grounds and only deslected the neck pickup with the selector switch, also took the output direct from the jak with a simple passive split. The HB was not modified, just lowered, so the oposing polarity pickup coil was significantly lower than the driver. So it is far from conclusive. That said, it did work...here's a pic... but still very much experimental... see if you can answer some of the questions above and really show us what you are doing... pete Link to comment Share on other sites More sharing options...
fookgub Posted March 18, 2006 Report Share Posted March 18, 2006 Ok, so I've haven't really made much for progress, but I thought I'd post a little teaser to prove I'm not just blowing smoke. This is the pickguard that I'm putting into my Yamaha Pacifica soon. The sustainer is in the neck position (I've got a cover for it), middle is a GFS P90, and the bridge is a DiMarzio Air Classic. As you can see, I haven't actually wired it up yet... I can't decide whether I should clip the leads short or leave them long in the interest of resale value. The 1/4" jack in the tone position is temporary, I'm just using it while I develop my sustainer amp. The other hole is going to be for the on/off and phase switch. I was hoping to put this in this weekend, but it doesn't look like it's going to happen. I decided to level the frets on the Pacifica while I had it apart. The leveling went fine, but I discovered I just wasn't man enough to recrown with a triangle file. I ordered a fret crowning file from Stewmac and I'll have to wait until that arrives to finish this project. Link to comment Share on other sites More sharing options...
psw Posted March 18, 2006 Author Report Share Posted March 18, 2006 Good stuff...another sustainer guitar will be fully installed before long... I really like the Pacifica...a decent cheap solid wood budget instrument and just perfect for something like this...if I do another sustainer guitar it may well be one of these. It's interesting to consider the effect of a device that has the potential for infinite sustain...perhaps a guitar with only moderate sustain is ideal. I still think you may need to have two switches on/off and harmonic, if only because of the number of poles required for the bypass. A single switch will require 3 positions to do this function...you will need dpdt for the harmonic function, and I needed all 4pdt to activate the thing...you may find yourself looking for a 6pdt 3 way switch...if they even make such a thing it will be hard to find, expensive and BIG under that scratchplate. Perhaps you could do it with a fancy rotary control...two mini switches are far easier both to find, install and operate IMHO... Have you put some thought as to where to put the circuit and especially the battery for easy access? I like the jack socket idea for testing...neato! I find a similar thing happens when I take a guitar apart...on mine I started installing a piezo...doh! Keep up the good work and thanks for the pics... pete Link to comment Share on other sites More sharing options...
fookgub Posted March 19, 2006 Report Share Posted March 19, 2006 I really like the Pacifica...a decent cheap solid wood budget instrument and just perfect for something like this...if I do another sustainer guitar it may well be one of these. It's interesting to consider the effect of a device that has the potential for infinite sustain...perhaps a guitar with only moderate sustain is ideal. Yeah, I thought the same thing about this guitar. I got this thing for free a few years ago from a friend who had decided guitar wasn't for her after all. It's seen a number of mods and electronics changes, but luckily I never did anything awful to it (I had another guitar the got the brunt of the seriously bad mods). Anyway, the previous owner applied a large Radiohead sticker to it, which I left intact as sort of a tribute to her, even though I'm not a Radiohead fan. People always look so disappointed when I explain that one to them... I still think you may need to have two switches on/off and harmonic, if only because of the number of poles required for the bypass. A single switch will require 3 positions to do this function...you will need dpdt for the harmonic function, and I needed all 4pdt to activate the thing...you may find yourself looking for a 6pdt 3 way switch...if they even make such a thing it will be hard to find, expensive and BIG under that scratchplate. Perhaps you could do it with a fancy rotary control...two mini switches are far easier both to find, install and operate IMHO... For now I'm leaving out the automatic bridge pickup selection. We'll just have to see if the occasional blast of howling feedback will convince me to do otherwise . Since I'm developing the amp outboard, I just put a DPDT in for a phase switch for now. The 4PDT I had seems to have been swallowed by my parts bin, but it will turn up eventually. Have you put some thought as to where to put the circuit and especially the battery for easy access? Yeah, the circuit will fit in the electronics cavity as long as I keep it to about 1.25" square. Otherwise I'll either put it in the trem cavity, which would be nice for EMI except that I'd still have to run a set of wires back to the phase switch, or rout an area under the pickguard below the middle pickup. I did the latter on a P-bass once and it worked out fine. For the battery, I'm going to install an 18V compartment (one of these) on the back. That way I can run the amp at 18V or at 9V and keep an extra battery in there. I finished wiring up the pickguard tonight. I decided to clip the pickup leads short since I'm too much of a pack-rat to sell them even if they don't work for me. Besides, it's always nice to have a box full of pickups because something that sucks in one guitar might sound fantastic in another. Link to comment Share on other sites More sharing options...
psw Posted March 19, 2006 Author Report Share Posted March 19, 2006 Good luck fookgub... For now I'm leaving out the automatic bridge pickup selection. Be prepared though, it's not just the bypassing but the complete isolation of all wiring that I was surprised at when I installed mine. I honestly thought that shorting or lifting one end of the coil would be enough but in fact found that, depending on the driver's phase, the drive signal would be sent through the earth into the amp. This is not just "howling feedback" as you might expect, but EMI that may interfere with the pickups signal (even cancel it) and as a result it would interfere with performance and be unbearable... But then, it does work in a fashion taking the signal from the output jack, so...hey, give it a go but be prepared to change. You can see with your driver some of the "comb magnetic shielding" through that cover. What is that made of, have you epoxied it or something? You have also broken from the basic pattern that I have tried but it all looks very promising. I actually have three pickups a stacked single coil HB in the bridge and two conventional single coils. The neck pickup has the driver built on top of it...this may explain some of the extreme switching I needed in my case. They are also very cheap unpotted single coils. I did figure that if I could get this thing to work, it would be able to work on just about anything. You still have the potential to change drivers, circuits and such at anytime anyway...even make a pickup/driver like mine that would slot right in to your driver slot, so never fear... For anyone who missed what my driver looks like...here it is again... The blue bit is the driver (3mm thick) and the black the pickup coil. The blade goes right through both to the ceramic magnet below and the top of the pickupcover is cut open to allow for the extra height of the driver... pete Link to comment Share on other sites More sharing options...
fookgub Posted March 22, 2006 Report Share Posted March 22, 2006 Ok, made some progress finally. The fret job went fine, and I have the guitar together now. The sustainer works okay up to the G-sting but requires quite a bit of coercion to get the B or E strings going. The coil is still vibrating audibly, so I'm going to have to rewind it. This time I'm going to stick closer to Pete's recipe with ~100 turns of 32 AWG wire. I'm having second thoughts about vacuum potting. We use 2-part poly for potting at work, and it dries like a rock. If I don't get it right the first time, I'm going to end up with a cool new paperweight. I'll probably just pot while I'm winding with epoxy. It would be a major pain, but I think a suitably motivated person with a razor blade could get that apart if needed. It's probably a moot point, anyway, since I'm going to try a design much closer to Pete's if the second coil on the Lace Sensor bobbin fails. It's a little early to tell if leaving out the bridge pickup selection stuff has cost me anything. I was very careful about the grounding when I wired this thing up. The system is oscillating when I crank up the gain enough to get decent sustain. I think it is mostly because due to direct coupling from the driver to the bridge pickup. I'm running at much higher power to compensate for vibrational losses in the coil and the fact that the 10-Ohm coil requires higher voltage to get the same power. I wrapped the driver leads in 2 layers of grounded copper tape, so I think EMI from the leads should be a minimal problem. Not to clog up this thread with non-sustainer stuff, but the P90 sounds awesome. I've never owned a P90 equipped guitar before (nor can I remember even playing one). It sounds about halfway between a Fender single coil and P.A.F. to me... lots of well-defined bass, nice full midrange, and a chime-y top-end that humbuckers lack. On the other hand, the Air Classic sounds awful in this guitar... very piercing and totally lacking in character, with low output to boot! Guess I shouldn't have cut those leads short after all. When I install sustainer driver v.2 I'm going to swap out the Classic for an Ibanez pickup I have around, but I haven't decided whether to go with an overwound P.A.F. or a hotter metal pickup like the BL X500 for the final install. You can't see much, but here are a couple photos of the current prototype. I snuck in a couple of my bench, too (pretty sweet, eh? ). http://www.ece.utexas.edu/~wrobert/yam2.jpg http://www.ece.utexas.edu/~wrobert/yam3.jpg http://www.ece.utexas.edu/~wrobert/yam4.jpg By the way, that comb filtering stuff is steel (I assume... it's ferrous, at least). I coated the entire thing in polyurethane varnish, though the bobbin was anodized, which is what accounts for the bronze tinge. I scraped a lot of the anodizing off in order to solder to the bobbin. Pete, Could you shoot me a link to a more detailed post about that driver? Did you wind the pickup, too? If not, where did you get that pickup with the blade polepiece? I really like the idea of having the driver on top of a normal single coil pickup. Imagine a guitar with a sustainer, a single coil, a P90, and a humbucker .... Link to comment Share on other sites More sharing options...
psw Posted March 22, 2006 Author Report Share Posted March 22, 2006 Hey there... it's there somewhere, I did photos of the entire winding process as I made it...I'll have to dig it out again, it's in the middle of the thread in three parts as I recall. The pickup is the original single coil pickup. The bobbin was slotted even though it had individual poles (the mid pickup is the same make) going down to the ceramic magnet. So I was lucky, just removed the poles, put in a blade, built a bobbin on top for the driver and wound away. But you could do it by putting a thin blade ontop of a pickup as long as the top of the magnets were flat (not staggered) which is fairly common. I think you have found the main culprit to your woes if you can hear or feel vibration in the coil. Potting is so essential and you are wasting high frequency vibrational energy vibrating the coil, and generating EMI, instead of vibrating those high strings! Did you pot it at all? I used PVA and although epoxy may be better, PVA is cheap and completely reversable and seems to do the job. Woodworking PVA dries pretty darn hard really and is safe to wind and presses naturally into all the spaces as you go. I think mine took about 200 turns but in truth I lost count and just went with an approximate resistance...it is a little less than 8 ohm as I recall. These things matter as there is a resonant frequency in coils and having loose windings will not only effect that, reduce efficiency but actually generate signals that will couple magnetically to the other pickups... Yeah, P90's are great...I wonder though if there is some loading on the bridge pickup with the sustainer circuit connected...does it sound the same with the sustainer wired in or completely removed (not just turned off)? I'm not sure that shielding the driver wires will help because the signal can be transferred to this directly to the guitars ground...but, it probably doesn't hurt it after all, one of the leads will be grounded effectively through the cicuit anyway, you just dont want to create a ground loop with it... Anyway, it sounds as if it is getting there and you still have a lot of options to play with.... pete Link to comment Share on other sites More sharing options...
psw Posted March 22, 2006 Author Report Share Posted March 22, 2006 (edited) OK...found it... here's a link to the two parts of building my current pickup/driver... Pickup / Driver photo tutorial...page 49 parts 1 & 2 There is a third part a little further on...I think that is mainly about installing it as I recall, hope that helps pete a-ha...Part 3 the finished driver Edited March 22, 2006 by psw Link to comment Share on other sites More sharing options...
fookgub Posted March 22, 2006 Report Share Posted March 22, 2006 (edited) Man you're fast with those replies! I'll check that stuff out tomorrow. I've got cheapo single coils coming out my ears, so I ought be able to rig up something like yours with parts on hand. I'm going to take another crack at the Lace Sensor first, though. Anyway, there shouldn't be any grounding or loading issues in my setup. The preamp input stage is just a first order highpass with a .033uF cap and a 1Meg resistor. I grounded the copper tape around the leads to the shield, but the jack is electrically isolated from the rest of the guitar. The negative side of the driver is grounded only to the preamp, which is referenced back to the guitar ground... no loops. I did "pot" my driver with a couple coats of polyurethane varnish after it was wound, but this obvoiusly wasn't enough, and I have a feeling that coil motion is the source of most of my troubles. What is PVA? Same thing as titebond? Edited March 22, 2006 by fookgub Link to comment Share on other sites More sharing options...
psw Posted March 22, 2006 Author Report Share Posted March 22, 2006 Hehehehe...I come from the future....hahaha What is PVA? Same thing as titebond? Yes...well white glue, woodworking glue...dries clear...water based... Basically it is a little flexible but it will fill any spaces, put a little on when you start winding and it will squeeze through the windings as in the photo above...add a little more as required as you go then tightly wrap with tape to keep it all together...it will probably take a little while to dry but you wont have to worry about shorts from testing the coil as it makes a good insulator too! You can see here how I got lucky with this cheap pickup...The poles there went through the coil bobbin slot and screwed into that metal plate. I used a 10mmx3mm blade from steel from the hardware store and got rid of that bottom plate. Once the pickup cover top was cut open it fitted perfectly...the removed pole plate being pretty much the same thickness (3mm) as the driver. All of this was a happy coincidence...I honestly didn't know! However, you could do something similar buy cutting down a blade to the thickness of the driver coil and sticking it to the top of a more conventional pole piece pickup I'm sure...or you could get lucky like I did, I'm sure millions of cheap pickups are made in this style... The above shows a couple of other drivers made before this one. One is a very cheap single coil bobbin with separate screw pole pieces, a little thicker but still worked well. The other is a 3mm separate driver and was the model that was reproduced for the pickup/driver. You can see some miniture RE magnets attached to it and the bobbin was actually made of very thin cardboard and later cut down to size. Something like this could easily be attached to a pickup and the pickup coil sensed through it. This driver worked well and was latter used with the "sustain box". Anyway...I will be away for a couple of days, but I'm sure that this is enough to keep you busy. I'm really curious as to how you are going to drive the thing but your main problem is this potting I suspect...it may be a little messy, but potting like this as you wind by hand (a machine will spray glue everywhere ) will ensure that it is glued all the way through and dries fairly solid! Best of luck... pete Link to comment Share on other sites More sharing options...
starry_night Posted March 22, 2006 Report Share Posted March 22, 2006 What I think you have done is built a driver on half a humbucker...is that right? But I don't know how you did it. pete yeah i did it that way... i simply took away the other half of the hum and then converted it to a single.. and the remaining bobbin i just used to be the bobbin of the driver. the driver is yes 3mm but 10mm tall, i used .22 wire as you recommended but i think ive gone to about nearly 10ohms far.. but the pics are not availabe yet so i cant clear out my explanations yet. ill be posting it whenever it is ready.. i am obtaining sustain but NOT the tonal quality that ive been expecting.. i am using the ruby but not the fetzer coz my uncle who happens to be an electronic tech said it will hardly gives a boost somewhat with that kind of calculations so he gave me a better one to work with.. actually i believe he took it from a kenwood design but still it directly goes into the ruby.. just minor modification on the circuit i guess.. and heres another obstacle, i am having trouble with my bridge... the pickup just kinda decreased its gain or power or something right after i shared its signal into the driver.. and when i tried to disconnect the sustainer, it came back to its normal performance... damn... Link to comment Share on other sites More sharing options...
fookgub Posted March 22, 2006 Report Share Posted March 22, 2006 and heres another obstacle, i am having trouble with my bridge... the pickup just kinda decreased its gain or power or something right after i shared its signal into the driver.. and when i tried to disconnect the sustainer, it came back to its normal performance... damn... You're loading the pickup too much. The input to your sustainer amp needs to be higher impedance. That's the purpose of the common collector (drain? is it a JFET... I can't remember) input stage in the Ruby-Fetzer circuit. am using the ruby but not the fetzer coz my uncle who happens to be an electronic tech said it will hardly gives a boost You uncle is right, but he missed the point. The input stage is for impedance matching, not gain. The LM386 has 40-odd dB of gain available... plenty for our purposes. Link to comment Share on other sites More sharing options...
psw Posted March 22, 2006 Author Report Share Posted March 22, 2006 (edited) I'll have to see the pics to understand... the driver is yes 3mm but 10mm tall, i used .22 wire as you recommended but i think ive gone to about nearly 10ohms far.. So is it 3mm on a 10mm bobbin? Oh, and more ohms is not better, mine is less than 8...I know it may not seem "enough" because you are used to pickup windings, but the driver is very different in design and purpose...more windings will alter the resonant frequency, the amount of power it can put out and most imporatantly, the speed at which this thing will work... i am using the ruby but not the fetzer So you are using a better preamp, or just going into the ruby? and heres another obstacle, i am having trouble with my bridge... the pickup just kinda decreased its gain or power or something right after i shared its signal into the driver.. and when i tried to disconnect the sustainer, it came back to its normal performance... This is classic loading symptoms. The purpose of the fetzer or whichever preamp you use is to avoid this "loading" effect. Common preamp designs are not always designed for very high impedance devices like guitar pickups so many people in electronics make a lot of assumptions it seems about what would be better. More boost would be good but if the input impedance is too low, you will get this effect and it wont work properly or sound good. i am obtaining sustain but NOT the tonal quality that ive been expecting.. Even so, it sounds like you are getting some response so that's a start. It sounds like you need to get a better preamp design, a fetzer in front of your preamp then into the ruby for instance would probably work to correct the problem... My design should also "theoretically" cause these kind of loading effect but doesn't seem to, at least on my guitar. That is a part of the reason why I don't provide more info on it, it may cause these problems and I don't want to produce a circuitboard for something that only works for my set up. But, I am hoping to get back to experimenting in the future, unless one of you guys beat me to it, and build a better circuit for it... I am even wondering if what it really needs is an active splitter in the preamp. A low impedance pickup like an EMG would be so much easier to work with as these loading effects would be non-existent. If you added a little active preamp to the guitar and made it active and then attached the circuit it would be much better, but then you would need power...it wouldn't work passively...something to think about... pete Edited March 22, 2006 by psw Link to comment Share on other sites More sharing options...
fookgub Posted March 22, 2006 Report Share Posted March 22, 2006 Hey Pete, could I get you to clarify a couple things about your driver? From what I understand, you started with a pickup that had individual magnetic polepieces on a steel baseplate. You scrapped the poles and baseplate, and added and a ceramic bar magnet in place of the baseplate. Then you used a single steel blade-style polepiece. Is this right? What about the neodymium magnets? Did you use those? Did you get the ceramic bar magnet from another pickup? Also, you said you used 2.2mm wire, right? That's closest to 31 AWG. Link to comment Share on other sites More sharing options...
psw Posted March 22, 2006 Author Report Share Posted March 22, 2006 OH...no, if I said 2.2 that is a typo, 0.2mm... Down here it's metric but speaking in mm is less confusing than SWG ASG etc... if it is a measurement it is what it is, a standard is more confusing... The pickup was ceramic, all the parts are original...I just took out the poles and the plate that held them in place. There are no neodyminium magnets in this one. I did experiment with them as a means to get the driver very small (from the hex drivers etc) but with this one, it is not necessary. There is a lot of misunderstandings about pickups (drivers) and magnets and in "magic" qualitities of various magnet types. You don't want a lot of power in your magnets, more power will not give more sustain, or gain. What is really important is magnetic field "shape"...what R.E. mags can do is make very compact shapes...not conventional nor better, perhaps even worse, maybe convienient... So yes...the magnet is the ceramic that was on it and very typical nth on one side (not the ends). The original poles were really just steel screws and the base plate just to keep them evenly spaced. The poles were not themselves magnetic. A couple of other points, the blade was used because it was easy but mostly it allows for even drive with string bends and avoids problems with aligning the strings with the poles. Also, don't add Rare Earth magnets to pickup magnets...they will demagnetize them, not good! pete Link to comment Share on other sites More sharing options...
fookgub Posted March 22, 2006 Report Share Posted March 22, 2006 OH...no, if I said 2.2 that is a typo, 0.2mm... Down here it's metric but speaking in mm is less confusing than SWG ASG etc... if it is a measurement it is what it is, a standard is more confusing... My mistake... I meant to type .22mm. 0.2mm is closest to 32 AWG. I agree that the various standards are annoying, but after using American wire gauges for so long I feel compelled to think in terms of them... much like the standard measurement system in general. Link to comment Share on other sites More sharing options...
psw Posted March 22, 2006 Author Report Share Posted March 22, 2006 My mistake... I meant to type .22mm. 0.2mm is closest to 32 AWG. I agree that the various standards are annoying, but after using American wire gauges for so long I feel compelled to think in terms of them... much like the standard measurement system in general. The problem with a lot of things like AWG is that it is American, not standard. American spelling is diverging so much from "english" and dragging the internet community with it, that many people believe that it is in fact "English", but is in fact the minority language. Nothing wrong with that, but the idea of inventing an "American Standard" when there were all ready perfectly servicable "British Standards" or simple imperial (not so good for these really small sizes) and metric. I'm sorry but "American Standard" always sounds like an oxymoron...it should be standard, american or not, and it was, before the USA decided they needed there own non-standard, standard! whewww...anyway, we spell english, measure in french and spend in dollars so I can hardly talk... BTW...metric really is easier for little things and acurate guitar sized measurements, and decimals are easier than fractions...but, I am old enough to have grown up with feet and inches and I still need to convert for most things...weird, I miss those handy chunks of measurement pete Link to comment Share on other sites More sharing options...
fookgub Posted March 23, 2006 Report Share Posted March 23, 2006 Took my coil apart today, and I figured out what the problem was. The polyurethane varnish didn't cure properly. It was dry on the outside, but inside it was a sticky mess. Apparently the outer layer dried into an airtight skin, which was flexible enough to let the coil vibrate, but didn't allow the inner layer to dry properly. Anyway, I'm going to use something with two parts to ensure this doesn't happen again. It will probably be epoxy, but we have a few two part urethanes that I'm going to check out too. Hopefully I'll be able to wind the new coil tomorrow and give it a try on Friday. Link to comment Share on other sites More sharing options...
starry_night Posted March 23, 2006 Report Share Posted March 23, 2006 pete of you can please check on your mail i sent you a drawing of what i did.. i cant post any pics on this site so i sent you the drawing instead.. is there any interference with what i did with my magnets? Link to comment Share on other sites More sharing options...
psw Posted March 24, 2006 Author Report Share Posted March 24, 2006 Hi there...back from surfing, the waves that is... Now...here's Starry's Pic he sent me... I cant really work out what is going on there, those magnets look very odd... Normally a humbucker has a single magnet, magnetized along it's length, one side being north the other south...this sits between the poles of the two coils so that one is magnetized north and south. I'm not at all sure what "P" means...but you can't really have a north without a south pole. Once you start combining magnets all sorts of strange things can happen to the combined magnetic fields...I'm not sure if the above is really right, it is unusual. Otherwise, the thin driver next to a single coil arrangement seems fine. A single conventional magnet from a humbucker would suffice so that the pickup was north and the driver south or visa-versa (it doesn't matter). Bear in mind that really this is about aesthetics here. Half a HB does not make a single coil as you'd find on a fender...there will be far less power and "tone" but it will work. Now, your question...is there any interference with what i did with my magnets? Well..the magnets don't do anything they are passive components in the device...it is the electromagnet in the coils that combines with the passive magnetic field that creates the interferance. The driver needs to put out a strong magnetic signal to move the strings...it is the nature of it. Anything magnetic, including other magnets will be caught up in the magnetic circuit just like wiring connects electric circuits with currents and voltages. I think you need to look at those magnets to see exactly how they are magnetised or check the drawing again perhaps... Fookgub...keep it up...it is near impossible to get a solid coil if you don't pot while winding...two part will set, forever, if it's wrong, it will stay wrong! If you try to wind it while potting take extra care, if you use a machine it will spray everywhere, but even by hand it will be messy. PVA (white craft glue, titebond, whatever) will set eventually but stay a little flexible. This is not too bad as there is some heat generated also in the coil and this will allow for expansion while epoxy may risk stripping the insulation in the coil if there are air gaps, etc. Superglue is not a good idea. Even if PVA does allow some vibration it will slow these resonant frequencies right down and cut oscillation out at any high frequencies at least, which are the biggest problem I'd say. And PVA is reversable both in the coil, on your fingres or (heaven forbid), your eyes while epoxies etc are not! It is cheaper too... So...good luck...I seem to be developing a golden tan, but not the beach blonde...more of a stressed grey look...oh well... pete Link to comment Share on other sites More sharing options...
fookgub Posted March 24, 2006 Report Share Posted March 24, 2006 Fookgub...keep it up...it is near impossible to get a solid coil if you don't pot while winding...two part will set, forever, if it's wrong, it will stay wrong! If you try to wind it while potting take extra care, if you use a machine it will spray everywhere, but even by hand it will be messy. PVA (white craft glue, titebond, whatever) will set eventually but stay a little flexible. This is not too bad as there is some heat generated also in the coil and this will allow for expansion while epoxy may risk stripping the insulation in the coil if there are air gaps, etc. Superglue is not a good idea. Even if PVA does allow some vibration it will slow these resonant frequencies right down and cut oscillation out at any high frequencies at least, which are the biggest problem I'd say. And PVA is reversable both in the coil, on your fingres or (heaven forbid), your eyes while epoxies etc are not! It is cheaper too... I wound the coil after work yesterday. I set the winder to about 80 RPM and took my time, so I didn't have any problem with the epoxy spraying. Took about 45 minutes, including time to go get the coil winder, mix the epoxy, make the electrical connections, etc. I tried the coil out last night, and, while it was markedly better, it was still oscillating and was slightly microphonic. I was pretty liberal with the epoxy, so I'm not sure what the problem is. Hopefully, it just hadn't set up fully and it will be better today. My scale threw a little fit yesterday, so I had to eyeball the epoxy mixture. I mixed in a little extra hardener to help it cure faster, but maybe it didn't go as fast as I thought it would. The extra I had in my petri dish had dried like a rock when I came in to work this morning, so the coil is definitely done by now. I'll let you know if it works any better today. Anyway, besides the oscillation, the sustainer is much more responsive. It actually works like a sustainer. I can hammer on a note anywhere on the neck and it will swell in volume quickly then reach a steady state with a good bit of sustain. Harmonic mode is still not working well. The oscillations aren't helping, and I think it needs a bit more gain still. I clipped the wire when it measured 8 ohms (it took 160 turns). Now it is measuring 10 ohms, so I'm not sure what happened. The solder joints are solid, so maybe there was a short inside coil that disappeared once the epoxy started to set up. It's an annoyance, though, as I really wanted to keep my coil in the 7-8 ohm range. I don't think the 10 Ohm coil is going to work with a 9V amplifier. I'll know more tonight when I do some more experiments on it, but I'll probably end up doing at least one more coil. I'm not sure whether I should scrap the Lace and try a design like yours or if I should give the Lace one more shot. I found a pickup in my parts bin that is almost identical to the one you used, so I think I may do both. Back to starry_night’s question, I assume "P" is supposed to mean south, but it doesn’t make any sense. As far as I know, you can’t have a magnet that is south in the middle and north on both ends. They are dipoles by nature. Also, the placement of the magnets is weird. They should be directly under the pole pieces and oriented so that one pole is towards the face of the guitar and the other pole is towards the back. Link to comment Share on other sites More sharing options...
1Way Posted March 24, 2006 Report Share Posted March 24, 2006 PSW, I was wondering if you have given it much thought about using optical pickups which are impervious to magnetism and would let your driver be stationed anywhere. I've never used them, just wondered what your thoughts are about them... Link to comment Share on other sites More sharing options...
fookgub Posted March 24, 2006 Report Share Posted March 24, 2006 PSW, I was wondering if you have given it much thought about using optical pickups which are impervious to magnetism and would let your driver be stationed anywhere. I've never used them, just wondered what your thoughts are about them... On a similar note, my piezo-equipped guitar did not have oscillation problems. Piezos are not affected by magnetism, and are more compact and easily available than optical pickups. Neither piezos nor opticals will sound like a magnetic pickup, though, so if you want that sound, you're stuck with magnetic pickups. Also, the ability to position the driver anywhere you want might not be much of a feature. It is more difficult to drive the strings the closer you get to the bridge. That said, I can only assume that, like pickups, changing the driver position will affect the harmonic content of the sustained note, so it might be worthy of experimentation. Link to comment Share on other sites More sharing options...
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