col Posted October 1, 2006 Report Share Posted October 1, 2006 (edited) OK, here's a just concieved, un-tried idea for the group.... The biggest (only) problem I have with my setup is the fuzz/fizz/crosstalk call it what you will.... The most likely cause for this is a combination of highly sensitive pickup with > 10000 turns combining with a powerful driver coil of ~160 turns... producing a parasitic transformer.... any low level crosstalk gets quickly amplified as it is fed back through the amplifier.... It seems like one way of dealing with this might be to use a very low impedence pickup - this would be less sensitive, and if made with only a few hundred turns of wire, the transformer effect would be much less of an issue (I think?). The problem here is that a very low impedence pickup will sound crap, and even if it can be made to sound good with some circuitry, what we really want is sustain with our favourite pickups and their sound... So what if we have a purpose built pickup just for the driver - none of it's sound goes to the output. As it is not intended to produce a sound, it needn't sound 'good' in the way traditional guitar pickups do - no need for thick warm tone etc. All it needs to do is get a signal from the strings. The driver, custom pickup and circuit would be completely electrically isolated from the existing passive pickup which would provide the guitar output. Although there would still be crosstalk between the driver and the passive pickup, there would be no feedback loop between them to amplify or other wise accentuate this crosstalk. It may be that depending on the guitar, a piezo pickup could be used, possibly even just mini stick-on piezo transducer rather than a 'proper pickup'... or even a little mic... (theoretically, it may even be possible to use the same coil for pickup and driver. The difference between the signal we feed the driver and the actual signal at the driver leads would be the signal produced by the strings in the coils field. This could be isolated by phase correction and negative feedback and send back to the circuit input. However, in practice, the complexity of the phase correction circuitry required and the manufacturing tolerences of the coil in order for it to match this circuitry would probably be prohibitive) Any thoughts ? (makes me think that some of the fancy phase correction circuitry in the commercial units might have been for reducing cross-talk ?) cheers, Col Edited October 1, 2006 by col Link to comment Share on other sites More sharing options...
col Posted October 2, 2006 Report Share Posted October 2, 2006 OK, here's a just concieved, un-tried idea for the group.... ... Hmm, after some searching - including this thread, it seems like this idea is getting even closer to the ebow. I like how the ebow has driver and pickup very close to each other (are they stacked?), although it seems probable that the only way this can be achieved without emi feedback being a problem is by their one string only approach. I'm also starting to wonder if having a seperate pickup for the driver will not really help matters as the crosstalk to the isolated output pickup will still be audible. I have another idea though - will try to get it set up and tested soon.... Col Link to comment Share on other sites More sharing options...
Primal Posted October 2, 2006 Report Share Posted October 2, 2006 Out of curiosity, Col, is your circuit overdriving the signal in any way? When I had the fizz/fuzz problem, I determined that it was due to my circuitry overdriving the signal, effectively sending a distorted signal to the driver. After backing off the gain, the fizz/fuzz completely disappeared. Link to comment Share on other sites More sharing options...
col Posted October 2, 2006 Report Share Posted October 2, 2006 (edited) Here is a good description of how an inductor coil works - could be useful, it was for me. (Roy Lewallen, http://www.w8ji.com/inductor_operation.htm) When a current flows into an inductor, it doesn't go round and round and round the turns, taking its time to get to the other end. An inductor wound with 100 feet of wire behaves nothing like a 100 foot wire. Why? It's because when the current begins flowing, it creates a magnetic field. This field couples to, or links with, the other turns. The portion of the field from one turn that links with the others is the measurable quantity called the coefficient of coupling. For a good HF toroid, it's commonly 99% or better; solenoids are lower, and vary with aspect ratio. The field from the input turn creates a voltage all along the wire in the other turns which, in turn, produce an output current (presuming there's a load to sustain current flow). Consequently, the current at the input appears nearly instantaneously at the output. Those who are physics oriented can have lots of fun, I'm sure, debating just how long it takes. The field travels at near the speed of light, but the ability of the current to change rapidly is limited by other factors. So please flush your minds of the image of current whirling around the coil, turn by turn, wending its way from one end to the other. It doesn't work at all like that. The coupling of fields from turn to turn or region to region is what brings about the property of inductance in the first place. Makes me think that the success of the 'thin driver' idea may really be an example of good "coefficient of coupling". My intuition suggests that the best configuration would be having the depth the same as the width - so a single coil driver with a 2mm core that is 10mm wide in total, the optimim thickness of the coil would be (10 - 2)/2 = 4mm Using the pickup winding calculator, an optimum config for an 8ohm coil using .23 (.25 inc insulation?)wire might be something like: core 2 - 6mm (probably not crucial) coil thickness 3.5mm 161 turns for 8ohm... cheers Col Edited October 2, 2006 by col Link to comment Share on other sites More sharing options...
psw Posted October 2, 2006 Author Report Share Posted October 2, 2006 Sorry I have not been active lately, come down with a virus or something .... btw, I'm not just sitting here be negative I'm trying to come up with solutions as well You have nothing to fear there on that account col...no one who has put in the thought and work you have and contributed so much could be seen as being negative. Mostly, the only people who have ever visited here or privately (through email) who have been negative never did any practical work or offered anything of value. Questioning my homegrown ideas is exactly why I post them. You have been coming across problems and exploring ideas that I too have tried or thought about...There is just too much to have communicated effectively...plus, my methods are hardly scientific. They are worth exploring, and I will comment on what I have found, but you seem to have come to the same conclusions. Your disappointment in the "fizz" or degradation or cross talk, or what ever the problem is, is completely justified. No such degradation is permissable to the success of this project. The accent on being able to run the device cleanly is quite rightly the test of this devices success, no matter what tone you ultamately wish to use it with. I think it is time to do a bit of recording, and I will see what I can do to demonstrate how cleanly mine will run. It is only with one sound (harmonics and crystal clean) that my setup will run with any change to the guitars output...other than the effects of infinite sustain. I take it that this degradation, fizz or whatever is not present when you drive the strings with the driver far enough away from the pickup? (ie over the neck) There should be no crosstalk at these distances. Maybe it is something else. I got similar problems by having other pickup coils still connected to ground and to some extent, the driver leads close to the pickup... You can see here the extent to which I have isolated the driver leads through the trem cavity, all the signal leads are also sheilded cable. Primal....My preamp (seen above also) has a very high gain and with the amp at 200x there will be a fair amount of distortion in my signal, yet it works ok. On of the resons I did all this work on cheapo disposable strats is that I thought the pickups would be the most susepatable to this kind of problem. I reasoned if I could do it on this kind of instrument, it would work anywhere. Perhaps I misjudged the effects on high gain HB pickups... I am curious as to how col is able to run his setup with such low amplification and power. How exactly do I measure the power consumption of my circuit? I think I do have a digital multimeter here (but that is about all)...I'd be more than happy to measure it out, very curious in fact. LK and me had an idea from the spec sheets, but that's not the same. I imagine the power consumption is within a range depending on how hard the thing is having to work? Anyway, give me a heads up, and I'll give you the low down. I like the rail idea BTW, but I do wonder if the recepie needs to be altered in some way...I am wondering about the resonant frequencies of the 4 ohm coils for instance. This thread, like the device itself is an enigma...the device concept is simple, but the devil is in the details. I have tried not to encourage people to read the whole thing because there are so many blind alleys and embarrassing mishaps and conclusions...much of which is confusing rather than helpful. I have and continue to learn as I go, as do we all. Doing it in public can be a risk...but never fear, all that gets buried as the thread goes on, till the next one comes along and follows down the same path. Fortunately col, you have caught on to the road signs a lot earlier than I. I will give some tales at some point as to the extent I went down those paths...I made the worlds smallest ebow at one point...hehehee Anyway...a little too sick to think, so more later...I still got to draw up my jigamathingy idea for coil making... pete Link to comment Share on other sites More sharing options...
onelastgoodbye Posted October 2, 2006 Report Share Posted October 2, 2006 using the calculator, turns out a 4 ohm coil @ 0.2 mm wire could be as small as 59 x 5 x 2 mm, So a dual rail driver would be about 59 x 10 x 2 mm with internal magnets (if you can ever find those). Also note how much of a difference the wire gauge makes towards the size of the coil and # of turns required. 0.23 mm wire 0.2 mm wire Link to comment Share on other sites More sharing options...
col Posted October 2, 2006 Report Share Posted October 2, 2006 (edited) Out of curiosity, Col, is your circuit overdriving the signal in any way? When I had the fizz/fuzz problem, I determined that it was due to my circuitry overdriving the signal, effectively sending a distorted signal to the driver. After backing off the gain, the fizz/fuzz completely disappeared. Yes, there will be some distortion depending on the input level, and this may make the fizz more apparent, but it is not the cause of the fizz. An easy experiment that proves the fizz is not caused by clipping in the amp circuit: take the driver out of the neck pickup cavity and use it by holding it above the strings (you'll need to switch the polarity (to avoid harmonic mode). Try using the driver further towards the nut - say around the 15th fret. You should notice that the fuzz/fizz is gone, now try the driver closer to the bridge than you normally have it - the fizz/fuzz will get worse (until you get to the howling emi feedback position). So the fizz is dependant on the distance between pickup and driver, power of driver signal, and sensitivity of pickup. Having no clipping in the driver signal may change the character of the fizz making it less buzzy, or 'warmer' but it will still be there given the same driver/pickup/signal level relationships. Backing off the gain of the circuit will reduce clipping in the signal that feeds the driver. It will also reduce the strength of the EMI radiated by the driver, in turn reducing the crosstalk between driver and pickup. With my 'DRI' AGC circuit, the more extreme the AGC, the worse the fizz gets because it tends to amplify lower level signals. This is a real shame because apart from the fizz, the effect with tha AGC turned up is superb - extremely playable, with great balance accross all strings and frets - with very low power requirements... I did some tests with my old driver, and it is not less noisy (as I had initially thought) that one side of the dual core... it is also not noticably less efficient.... So the EMI bucker really does dramatically reduce EMI feedback.... I was then bringing the crosstalk back up to an audible level with my DRI circuit.... I can turn this down, so it still helps(but not as much) with balance and power drain without having such an impact on crosstalk, but I would much rather have the best of both worlds . (If it came down to it, I think I would probably prefer to go with a piezo pickup coil driver combo for sustaining rather than ditch the AGC... best to find a cure for the problem though if possible.) using the calculator, turns out a 4 ohm coil @ 0.2 mm wire could be as small as 59 x 5 x 2 mm, So a dual rail driver would be about 59 x 10 x 2 mm with internal magnets (if you can ever find those). Also note how much of a difference the wire gauge makes towards the size of the coil and # of turns required. 0.23 mm wire 0.2 mm wire Yep - watch out though, this calculator is pretty accurate, but it doesn't account for the sag and extra bulk caused by potting compound, so dont expect real world coils to be quite as narrow Col Edited October 2, 2006 by col Link to comment Share on other sites More sharing options...
col Posted October 2, 2006 Report Share Posted October 2, 2006 (edited) ... I take it that this degradation, fizz or whatever is not present when you drive the strings with the driver far enough away from the pickup? (ie over the neck) There should be no crosstalk at these distances. That is exactly right - it starts getting noticable at about fret22-23 Maybe it is something else. I got similar problems by having other pickup coils still connected to ground and to some extent, the driver leads close to the pickup... I've just tried isolating the system completely - using a cheapo single coil pickup purely for the driver and running the bridge HB direct to the output - no shared earth, no electrical connections whatsoever. Didn't make much difference - not enough anyway. Might do a little bit more experimenting in this area, but I don't expect it to yield any useful results. I am curious as to how col is able to run his setup with such low amplification and power. Part of the problem I'm having is that my circuit does amplify the crosstalk somewhat. Still havn't tried a 'squelcher' which may help a little, but I don't think it would be a complete solution... A good analogy for how my circuit can run on such low power is driving a car: When you accellerate, you have to mash the gas - using lots of fuel/power. this is like the stage where you get the swell effect as the sustain effect kicks in.... When you're up to speed in your car, you can keep it at that speed with much less gas - you only need enough to work against the friction of the road, bearings and air... My driver circuit works similarly - as the signal gets up to the 'threshold' level (speed limit) it backs the power off until there is only just enough to keep the string going just hard enough to stay at that level. What this means is that if you hit the strings hard, the power is very low until the natural vibration comes down to the 'threshold'... conversely, if you play very gently, it uses a bit more power during the short 'swell' as it brings the string(s) up to the 'threshold' level How exactly do I measure the power consumption of my circuit? I think I do have a digital multimeter here (but that is about all)...I'd be more than happy to measure it out, very curious in fact. What I did to measure the battery drain is plug my DMMs leads in the correct sockets for measuring current (not all meters have this, but most do) and set it to dc current. Connect the negative terminal of the battery to the circuit as usual, connect the positive terminal of the battery to the red(+ve) lead of the meter and the black(-ve) lead of the meter to the circuits 9V power pin. So basically, you open the positive battery connection and bridge it with the meter. Best start with a high current setting on the meter until you're sure - don't want to trip the fuse. I imagine the power consumption is within a range depending on how hard the thing is having to work? Yes, the power consumption is dependent mostly on how hard the circuit is having to work - mine drops to about 10.5mA when the strings are damped, and peaks at from 22 to >60 depending on the gain and AGC settings. fwiw, 22mA at 9v is 0.198Watts, and a fair chunk of that is used by the buffers and AGC, so if the crosstalk can be fixed, it may be possible to use a lower power discrete amp rather than the LM386... maybe a discrete class D amp based on a 555 timer.... (/me runs around gibbering and frothing at the mouth) I like the rail idea BTW, but I do wonder if the recepie needs to be altered in some way...I am wondering about the resonant frequencies of the 4 ohm coils for instance. The resonant frequency will be far above the audible spectrum, so not an issue - also, when its wired in series, its really a single 8ohm rather than 2 x 4ohm (i think?) The rails seem really good - much better than the slim single coil driver - at least in my A/B tests. Just need to get it as narrow as possible. ...a little too sick to think, so more later...I still got to draw up my jigamathingy idea for coil making... Hope you feel better soon Col Edited October 2, 2006 by col Link to comment Share on other sites More sharing options...
googlymoogly Posted October 2, 2006 Report Share Posted October 2, 2006 (edited) Hey guys, I was following this thread for the better part of a year, but I forgot about it about a year ago... I can't really read another year's worth of posts (for exactly the reason psw stated in his previous post), but I tried searching... fruitlessly... too many irrelevant hits. Anyway, I believe you still have EMI problems, and that's why you favour the thin driver design, yes? I know you've studied the Sustainiac patents, but do they actually have this in them? http://forum.musikding.de/yabbse/index.php...g67381#msg67381 That copper shielding can only be for shielding EMI, right? The thread is in German but the important stuff is in English. If you've already seen this thread with a disassembled Stealth, just ignore me. I'm just double-checking to see if you have, and help in any little way I can, because I'm very interested in the goings-on of this project, but sadly I don't have the know-how (or time, right now) to delve deeper into the details, though I would want to. You probably already know all this, which just means I'm annoying you with this post : ) Edited October 2, 2006 by googlymoogly Link to comment Share on other sites More sharing options...
onelastgoodbye Posted October 2, 2006 Report Share Posted October 2, 2006 If you've already seen this thread with a disassembled Stealth, just ignore me. I'm just double-checking to see if you have, and help in any little way I can, because I'm very interested in the goings-on of this project, but sadly I don't have the know-how (or time, right now) to delve deeper into the details, though I would want to. You probably already know all this, which just means I'm annoying you with this post : ) No we haven't seen this yet...thanks very much for posting! Tim Link to comment Share on other sites More sharing options...
onelastgoodbye Posted October 2, 2006 Report Share Posted October 2, 2006 (edited) double post Edited October 2, 2006 by onelastgoodbye Link to comment Share on other sites More sharing options...
psw Posted October 2, 2006 Author Report Share Posted October 2, 2006 Welcome Googlymoogly.... Anyway, I believe you still have EMI problems, and that's why you favour the thin driver design, yes? I know you've studied the Sustainiac patents, but do they actually have this in them? http://forum.musikding.de/yabbse/index.php...g67381#msg67381 That copper shielding can only be for shielding EMI, right? The thread is in German but the important stuff is in English. If you've already seen this thread with a disassembled Stealth, just ignore me. I'm just double-checking to see if you have, and help in any little way I can, because I'm very interested in the goings-on of this project, but sadly I don't have the know-how (or time, right now) to delve deeper into the details, though I would want to. You probably already know all this, which just means I'm annoying you with this post : ) No...we haven't seen this, fantastic. Also...great to see another sustainer thread...this one is better than the spanish one that surfaced, hey tim ) Pity my German is about as good as Inspector Rex's english. Nice to see we have a reference to both this thread and to the tutorial too. Looks like a few interesting things discussed... Those photos are really good... The copper can only be for electrical sheilding. To be magnetic, it would have to be iron or something. This is typically done around pickups as an earth and since this is a "stealth" it is used also as a low impedance pickup, so it probably relates to that... This is interesting...a wide laminated core, you can see the depth of the windings, the thickness of the bobbins keeping the coil from the core....and is that wax potting? Obviously not using this treads theories of thin coils and cores!!! Don't know what is going on here, but may D class amps run 4 ohm loads...but how did they get 2 6's to equal 4??? One thing about the bi-lateral that is interesting compared to the rail design is that to some extent the field is attracted across the strings (N-S) rather than along. Something to consider... Thanks a lot...perhaps I should send them a hello from us here... pete Link to comment Share on other sites More sharing options...
spazzyone Posted October 2, 2006 Report Share Posted October 2, 2006 (edited) HMMM! laminated cores.......i tried that but with the thin single theory http://i32.photobucket.com/albums/d38/femf.../Picture006.jpg "Note the offset" to the high E side this was my third driver. i took apart a transformer for the "wire" as i had none. so i used the transformer wire thats when i thought about laminations offset to get the power needed for the high strings my next attempt will be the bilateral with that 8 watt amp if that does not work ill stick to the "rail" with my 20 watt setup as it works but i cant seem to switch modes as there is no differance when i reverse the pos/neg wire's going to the driver and it seems to sustain some notes and send others into harmonics which you can hear in my first "sounds" post Maybe switching the phase going into the amp might work ? Edited October 2, 2006 by spazzyone Link to comment Share on other sites More sharing options...
col Posted October 2, 2006 Report Share Posted October 2, 2006 Don't know what is going on here, but may D class amps run 4 ohm loads...but how did they get 2 6's to equal 4??? bad meter ? dodgy connectors ? for low resistances, even having the probe leads tangled can effect readings... connected in parallel: 1/(1/6.3 + 1/6.3) = 3.15... in series obviously it should be 12.6. wierd. One thing about the bi-lateral that is interesting compared to the rail design is that to some extent the field is attracted across the strings (N-S) rather than along. Something to consider... yep, something to consider for sure... The laminated core and the nice big gap between the coil and the core also imply that they are more concerned about eddy currants than we have been. Maybe there are significant efficiency gains to be had ? Col Link to comment Share on other sites More sharing options...
googlymoogly Posted October 2, 2006 Report Share Posted October 2, 2006 (edited) Ah, feels great that I could help (or act as a proxy, rather)! Re: copper RFI shielding, I might be a newbie, but I'm pretty sure it's a common material for shelding for RFI. Just as a relevant example, how about copper-painted pickup/switch cavities in guitars for one (common singlecoil guitar mod)... Edited October 2, 2006 by googlymoogly Link to comment Share on other sites More sharing options...
onelastgoodbye Posted October 2, 2006 Report Share Posted October 2, 2006 Some observations.. Also...great to see another sustainer thread...this one is better than the spanish one that surfaced, hey tim wink.gif ) Pity my German is about as good as Inspector Rex's english. Nice to see we have a reference to both this thread and to the tutorial too. Looks like a few interesting things discussed... I think it was portuguese . Didn't he drive the thing off of a 3 v button cell? My German is decent at best, what i could make out is that they have had 2 or 3 successfull attempts with a crude 0.2 -0.3 mm coil and a 15 watt amp, also a little gem in there somewhere. there's some pics and soundclips if you click the link in post #39 on page 3. Tey're still pretty much in the dark as to how and why things work or don't work, I'm sure they'll appreciate all the help they can get. yep, something to consider for sure... The laminated core and the nice big gap between the coil and the core also imply that they are more concerned about eddy currants than we have been. Maybe there are significant efficiency gains to be had ? I don't know, the more I learn from the sustainiac and fernandes designs, the more it seems to stem from some serious guesswork and extensive experimenting rather than exact science. Furthermore, the build quality of the sustainiac doesn't seem to be super-top-notch. I have great respect for these guys, and there's nothing physically wrong with the driver (looks pretty old too), but it's probably not as sophisticated as we make it out to be. The circuitry, that's something else. So, the "bobbin" air gap is more of an "ease of production" thing, I think. Especially if they're machine winding. So much easier to pop the core in afterwards. Maybe the gap between the top of both cores is of more interest to us ( but I still wouldn't make too much of it). Now, the laminating... I have done this, like Spazzy, and it doen't seem to make a big difference. Also, with the thin cores we're using there's only so many laminates you can practically use. On the other hand, it is usually easier to source (and cut) steel sheet than solid cores of suitable material and dimensions; and the laminates give you more freedom in experimenting with various core widths; so there's no real reason NOT to do it. except for the fact that the material i'm using is some sort of hardened steel, hard as hell to saw through. If I didn't know any better i'd say it was stainless One thing I'm wondering is if they drive both coils with a separate signal? there's no difference in wire gauge...so any compensation must be electronic. Also, If they're running it as a pickup, would they be using the same preamp (surely they are gonna need a preamp to beef up the signal, no)? Link to comment Share on other sites More sharing options...
col Posted October 2, 2006 Report Share Posted October 2, 2006 I don't know, the more I learn from the sustainiac and fernandes designs, the more it seems to stem from some serious guesswork and extensive experimenting rather than exact science. Furthermore, the build quality of the sustainiac doesn't seem to be super-top-notch. I have great respect for these guys, and there's nothing physically wrong with the driver (looks pretty old too), but it's probably not as sophisticated as we make it out to be. The circuitry, that's something else. Yep, a sign of good product design is that it can be made cheaply and with wide manufacturing tolerences - and still work... So, the "bobbin" air gap is more of an "ease of production" thing, I think. Especially if they're machine winding. So much easier to pop the core in afterwards. I remember reading (not sure where - possibly in this leviathan of a thread) that the gap between coil and core is important in reducing eddy currents (pretty sure it was eddy currants). The thing is that power efficiency drops off linearly with the size of the gap while eddy currents drop off (ouch) with the square of the gap width - so make the gap a little wider, lose a little power transfer and a lot of eddie currents.... (I REALLY wish I could find that page again - if it wasn't eddy currents, then I'd like to know what... and I hate being so vague)... so there's an ideal gap width - narrower and the efficiency losses due to eddy currents are greater than the saving of a narrower gap... wider and the power transfer losses due to gap width outweigh the saving due to reduced eddy currents.... Now, the laminating... I have done this, like Spazzy, and it doesn't seem to make a big difference. Also, with the thin cores we're using there's only so many laminates you can practically use. On the other hand, it is usually easier to source (and cut) steel sheet than solid cores of suitable material and dimensions; and the laminates give you more freedom in experimenting with various core widths; so there's no real reason NOT to do it. except for the fact that the material i'm using is some sort of hardened steel, hard as hell to saw through. If I didn't know any better i'd say it was stainless Two possibilities I can think of, both related to the bottom line. Either #1 A laminated core is no benifit other than transformer factories in china can give you any shape core you want for a _very_ low cost, but it has to be laminated coz thats what they're tooled up for. or #2 A laminated core is quite a bit more expensive than soft iron/steel stamped out of a sheet - in which case it must have a measurable impact on the efficiency and/or quality of the driver... btw, something you might want to try is the sheet metal used to make the casings for computer power supplies. I have one that I decided to cut up for other purposes. Its nice soft metal, can cut it with tin snips, and it seems to be very magnetic - I guess they would use an alloy with good EMI shielding properties for housing a PC power supply. I was going to use it to make a driver core, but before I got around to it, I discovered the range of iron/steel bars available at my local DIY superstore... end of story One thing I'm wondering is if they drive both coils with a separate signal? there's no difference in wire gauge...so any compensation must be electronic. Also, If they're running it as a pickup, would they be using the same preamp (surely they are gonna need a preamp to beef up the signal, no)? I doubt it - I was thinking about how you could reduce crosstalk by having one signal for each side... so you'd only need half the power for any one string and therefor produce less EMI for the same string reaction... BUT you would need a custom bi-lateral pickup for this to work (still might be worth consideration ). Really it comes down to how much less radiation is produced from a coil half the size - is the relationship linear, cubic, logarithmic.... ??? more to add the the ever growing list of possible part solutions to waste some time and resources on cheers Col Link to comment Share on other sites More sharing options...
spazzyone Posted October 3, 2006 Report Share Posted October 3, 2006 (edited) Now, the laminating... I have done this, like Spazzy, and it doen't seem to make a big difference. I beg to differ on this while the offset idea did not produce the results i was hopeing for (no extra high string responce) i did obtain a better responce maybe its the material i used? but i did not persue it because the rail pickup still worked better so i kept chasing better solutions for that instead if you look at at my post you will note my driver is the same i just changed the cores (i also tried solid steel i had lying around) (limited resources) i am curently back to hacking up humbuckers in half for (bilateral) bobbins as that 8 watt amp i have have is only 1-3/8"x2" (and fits a control cavity pretty well) and should be enough to power the driver (i think i hear Pete laughing at me) no i don't realy desire to abuse power like G.W.Bush it just happens (at least i'll provide enough) LOL Edited October 3, 2006 by spazzyone Link to comment Share on other sites More sharing options...
ebenezer shred Posted October 3, 2006 Report Share Posted October 3, 2006 does anyone have a perfboard layout for the fetzer/ruby? I tried to make one on that computer program but I think I got it wrong. Link to comment Share on other sites More sharing options...
col Posted October 3, 2006 Report Share Posted October 3, 2006 does anyone have a perfboard layout for the fetzer/ruby? I tried to make one on that computer program but I think I got it wrong. If you post your layout, I'll double check it for you. Col Link to comment Share on other sites More sharing options...
ebenezer shred Posted October 4, 2006 Report Share Posted October 4, 2006 i did it on the program from diyfever.com, but I don't know how to post it. do you know how? Link to comment Share on other sites More sharing options...
Primal Posted October 4, 2006 Report Share Posted October 4, 2006 i did it on the program from diyfever.com, but I don't know how to post it. do you know how? Take a screenshot (Print Screen key on keyboard, then open up MSPaint and press Control+V), upload the picture to photobucket, and post the link. Link to comment Share on other sites More sharing options...
psw Posted October 4, 2006 Author Report Share Posted October 4, 2006 So much lately...too much to comment on right now... A lot of the conclusions you are coming back to are the same as mine without me anyway...I'll contribute on that later... Meanwhile, here is a proposal for making a jig to make coils suitable for driver designs that I think would be versitile and adaptable to either my single coil or rail driver systems...not tested, but hey! I'd suggest making the parts for the jig be from aluminium. The bolts (2) may be hard to source...they will need to be thinner than the temporary former for the core of the coil. The former blade is important (you cant just coil around two bolts) and must fit flush with the top and bottom pieces. The "bobbin" is of paper or card and the potting I am proposing with this system is still PVA. If you cut the paper so that the grain runs through the core, as it shrinks it will tighten up the coil. Use liberal amounts of PVA during the winding process so that the coil is tatally saturated (a little messy I know!)... So the procedure is to place one thin sheet of oversized card on the bottom, push the bolt through the pieces and this paper tight. Hold the card back with tape if necessary, then wind your coil. Then, take the wire leads out the ends, fold the top piece down and then use two other pieces to squeeze the sides and the paper into a neat tight unit. The two pieces of paper will glue together and the coil can be removed for further drying. The bottom sheet will hold it in shape while the top will encapsulate the coil (except at the ends)...you could put a top sheet in too, but it maybe trickier to remove the dummy blade. The paper shrinkage should help in releasing this, and make the coil even tighter. Don't apply too much pressure on the claping pieces, you don't want to damage the coil (or even the paper too much). Although I have not made this jig, I have made such a driver and it has held up well to this day (if anything, better than the plastic topped one I use now...) This is also the driver that I used on the "sustain box" with the LP pictured elsewhere...so the principle is sound... After it has set a while you can cut the paper away from the ends to shape, but try to keep the windings wraped by folding over the sides a little. The end result should be a stable wire coil with a minimum of paper reinforcement and glue holding it together...it should even be slightly flexible and have no internal vibration. Making a bobbin in such a way means that you could make pairs for a rail driver, experiment with different internal cores and materials, all knids of things. You will need to be sure that the blade can no move within it, but I think the concept is sound and allows for versatility in use for all kinds of things. Especially for those wanting to experiment, a different internal former will give thicker or thinner coils, more windings a wider 8 ohm coil, or smaller a pair of 4's... Possibly it could be improved upon, but is certainly what I would be trying next, if I were/ when I am next making coils for driver development. Now...if the thing seems like it would look a bit primitive, bear in mind you could hide the thing eventually in some kind of cover or set it in epoxy for a professional finish and ultimate solid construction... pete Link to comment Share on other sites More sharing options...
psw Posted October 4, 2006 Author Report Share Posted October 4, 2006 EB...I think I posted this already of the fetzer on it's own...on vero And I am pretty sure I got this thing right in the end for my version of the LM386 part that would connect to it though perhaps it could be checked... Otherwise, DIY layout creator also has the Ruby in various forms and you could replace the buffer with the fetzer if you so desired. I kind of like the idea of them being separate, at the least, if all else fails, the fetzer makes a great booster and the LM386 could be used to make a mini practice amp! Hope that helps...their is a library of circuits such as these (some in perf) over at the DIY layout creator's website shown under the above pics...hope that helps... pete Link to comment Share on other sites More sharing options...
psw Posted October 4, 2006 Author Report Share Posted October 4, 2006 opps I forgot this one...burning through the pages now.... How exactly do I measure the power consumption of my circuit? I think I do have a digital multimeter here (but that is about all)...I'd be more than happy to measure it out, very curious in fact. What I did to measure the battery drain is plug my DMMs leads in the correct sockets for measuring current (not all meters have this, but most do) and set it to dc current. Connect the negative terminal of the battery to the circuit as usual, connect the positive terminal of the battery to the red(+ve) lead of the meter and the black(-ve) lead of the meter to the circuits 9V power pin. So basically, you open the positive battery connection and bridge it with the meter. Best start with a high current setting on the meter until you're sure - don't want to trip the fuse. I imagine the power consumption is within a range depending on how hard the thing is having to work? Yes, the power consumption is dependent mostly on how hard the circuit is having to work - mine drops to about 10.5mA when the strings are damped, and peaks at from 22 to >60 depending on the gain and AGC settings. fwiw, 22mA at 9v is 0.198Watts, and a fair chunk of that is used by the buffers and AGC, so if the crosstalk can be fixed, it may be possible to use a lower power discrete amp rather than the LM386... maybe a discrete class D amp based on a 555 timer.... (/me runs around gibbering and frothing at the mouth) ...a little too sick to think, so more later...I still got to draw up my jigamathingy idea for coil making... Hope you feel better soon Col Alright, I think I did this ok... Strings damped about 20-21mA Flat out Sustain about 100-102mA or so it would seem...battery could be a little fresher... As could I...but I am getting better, thanks for your wishes... Looks like you are getting quite a bit of improvement in battery consumption...I wish that I could experiment with this further as this guitar would amke an excellent test bed for all kinds of things. The amp/preamp are separate and your AGC could probably be slotted in there for a direct comparison...maybe one day. It could also be that your circuit achieves a different kind of effect... Have heard clips like this BTW? beckistan.mp3 and sirensea.mp3 from the Sustainer Sounds Thread...oh and this big production number of Dizzy's secret mid bi-lateral driver, sustainer guitar diablo_theme.mp3 to prove that it is possible, even if Sustainiac don't make them! In many ways your circuit concept may be superior in performance, and lower in battery consumption, as well as being adjustable to achieve these kinds of effects too (a different more useful "sensitivity" control perhaps). Anyway...hope this adds a little to the hard data and encourages you further. At 200x amplification, you'd expect a bit of power to be drawn. Perhaps, as always it seems, the secret is in the driver. The commercial drivers do seem to mimic the size and shape of a conventional pickup in all it's incarnations...I think ultimately the rewards will be found by thinking outside of these "limitations", even if I do seem married myself to the concept of a pickup/driver for practical purposes. I also hope the coil winding ideas provides some food for thought and further encouragement to deal with the driver technology... pete ps... I also put up a link to that German forum and if we have visitors from over there Willkommen (ok...so that's the extent of my German language abilities) Link to comment Share on other sites More sharing options...
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