Sustainer Ideas

[Truth_David]

Otra cosa que hay que tener en cuenta para que el fetzer/rubi funcione es el tipo de lm 386 que se utilize, y puede ser la causa de que no funcione bien, aqui pongo los modelos que hay con sus respectivas potencias.

3 variations:

ka386 b 600mW

LM386-N1 cheapest variety 300mW

LM386-N3 500mW

LM386-N4 expensive variety 700mW

saludos.

Translation:

Something else to take into account in order for the Fetzer/Ruby to work is the type of LM386 you use, which could be a reason for it not working well; here is a list of the existing models with their respective power attributes:

3 variations:

ka386 b 600mW

LM386-N1 cheapest variety 300mW

LM386-N3 500mW

LM386-N4 expensive variety 700mW

Hope this helps,

David

[FlashBandit]

Hey, I just want to say thanks alot to all of you helping so much, namely PSW, zfrittz, David, and col, you guys are awesome. I disassembled my guitar and I've gone back to the basics. It's starting to work real well. I'm redoing a couple coils and I hope it works even better. This is again all thanks to you guys, I can't thank you enough, I'm so excited to get this working.

Quick question: First, I just have the driver and bridge hooked up. When the driver is in the necks previousl location, I get good feedback when it's out of phase with the strings (harmonic mode). However, when I change the phase with the DPDT to go into normal sustain mode, the driver sends some sort of feedback through the bridge pup. I'm assuming it's some magnetic field produced from the driver that induces currents in the bridge pup because when I move the driver away, I can get the noise to stop but when it's close to the bridge, it makes a high pitched squeal, and when I move it really close to the bridge pup, the squeal drops to a lower sort of rumble. Any thoughts?

[zfrittz6]

Lo del chillido es porque hay demasiada potencia por eso es importante una bobina bastante buena para que haga vibrar las cuerdas sin utilizar demasiada potencia, asi cuanto mejor sea esta menos EMI y por lo tanto mejor funcionamiento de todo el circuito.

Tambien debes comprobar dandole la vuelta a la bobina pues segun su posicion tendras mas chillido o menos, es decir la parte que pones abajo la pones arriba y compruebas.

Saludos.

[psw]

Hey, I just want to say thanks alot to all of you helping so much, namely PSW, zfrittz, David, and col, you guys are awesome.

Thanks, I'm impressed by the number of people dedicated to helping people out with this.

I disassembled my guitar and I've gone back to the basics. It's starting to work real well.

That's the way. Everyone seems to jump ahead to the total installation and all, even beyond the limitations of the design. While important to keep it in mind, not everything is possible, and you really need to get it working before leaping ahead. A lot is learn't about it's limitations and enthusiasim generated for developing it further by taking this approach.

I'm redoing a couple coils and I hope it works even better. This is again all thanks to you guys, I can't thank you enough, I'm so excited to get this working.

Most, including me, need to have a few runs at the coil at first, although yours looked particularly good and follows the formula...

Quick question:... When the driver is in the necks previousl location, I get good feedback when it's out of phase with the strings (harmonic mode). However, when I change the phase with the DPDT to go into normal sustain mode, the driver sends some sort of feedback through the bridge pup.

This is the dreaded EMI effect, and it is worse in one phase to another. It is possible that your single coils are more suseptable than other pickups to this effect. My strat has a stacked SC sized HB in the bridge that might be helping things, though I have had it working with single coils.

The EMI or fizz problem is a balancing act. You need a driver that limits this, in my design it is the shape and size of the coil. It should be noted that when positioned below the strings, things do improve a bit, than over the strings in testing mode. You can see that we will have to get very clever to mount the driver in the middle position, certainly this basic design wont cut it.

So, it may be you will need to back the gain off from the circuit till just below the level of interferance. Hopefully you will still get the level of sustain you desire with this reduced gain, and your battery will last a little longer.

The other area is in the coil, a better driver will produce a little less EMI. Yours looked pretty good, but you could try reducing the core and the bobbin thickness so that the coil is right under the strings. The driver needs to be as close as possible to the strings, the bridge pickup adjusted really close helps too.

I am hoping to build a bobbinless coil that will sit under my single coil's cover so it will look completely stock. This pickup has alnico rod magnets in the fender style but is built on a bobbin so it is likely that I can press the magnets up a little and even from their staggered orientation. I am wondering how I am to fit the controls, ideally a rotary switch replacing one of the tone controls for on off and harmonic modes would do the trick, and I think I can find a 4pdt 3 postion switch, but not sure if this will do it, and if I will still suffer switching noise when I turn the thing off! Then there is the issue of fitting the thing within the guitar...there are a few issues to consider there and perhaps an external box has merit here as it would allow for more switching options and for the possibility of trying out larger and more elaborate circuits like col's. In the meantime, still working through my personal predicament and waiting for a clear spot in the road before I get to any of this kind of thing. I have spent a few days clearing and boxing up my stuff and found a whole lot of unfinished projects including my pickup winder contraption. Originally I was looking to make pickups not a sustainer, so perhaps this is something I will also be exploring.

Anyway...good to see it is working to some extent and that progress is being made...it is simple in principle and quite easy to construct, but the devil really is in the details....keep on keeping on... pete

[flickoflash]

I have been very impressed with the discussion & developments that have been discussed on these threads.

I have started a new forum community for Les Paul Guitar lovers & invite you to join & participate in the development group for pickup design & sustainers

http://www.mylespaul.com/forums/

http://profile.myspace.com/index.cfm?fusea...endid=174765726

ToneFreaks

Tesla’s Coil “F.A.P” Pickup Development Group

Sustainers X-Factor Project

Thanks, Flick

Edited April 9, 2007 by flickoflash

[FlashBandit]

A crazy thought just came to me out of the blue, and I want to know what you guys think:

Imagine a pickup/driver as a collection of individual coils around a bar all connected in series. How do you think a pickup would sound if you had a whole bunch of individual coils around a bar connected in parallel? Or maybe each coil could wrap around a few times and then connect in parallel? I'm sure you'd get some new sounds. This could be done most easily by wrapping a coil around the center bar (or poles) with 540 degrees of rotation and leaving two leads of wire coming out. Do this a whole bunch of times and have a whole bunch of leads coming out, then wind and weld them together. Left side wires would make one lead, say ground, and the right side wires would make the other lead, say positive.

This configuration could have several immediately obvious benefits. In general, this coil would last longer since, even if one wrapping got severed, the pickup would still work fine. It would (I think) only have one phase unlike todays pickups that have two. That would mean your pickups could never be out of phase with each other. I'm sure it would produce new sounds and coupled with standardly wrapped pickups, you'd have all sorts of neat possibilities.

I'm thinking this configuration might especially help with our sustainer project in curing certain ailments that EMI produces. I dunno, maybe it's worth something, maybe not. But with our driver only having 100-200 windings, it may be easy enough to test. Pickups have thousands of windings and may be more difficult. Let me know what you think!

[col]

A crazy thought just came to me out of the blue, and I want to know what you guys think:

I think its a crazy idea !

Imagine a pickup/driver as a collection of individual coils around a bar all connected in series.

There is no pickup/driver a this point (at least not that I am aware of). Pickups and drivers require very different coil specifications.

How do you think a pickup would sound if you had a whole bunch of individual coils around a bar connected in parallel? Or maybe each coil could wrap around a few times and then connect in parallel? I'm sure you'd get some new sounds.

This could be done most easily by wrapping a coil around the center bar (or poles) with 540 degrees of rotation and leaving two leads of wire coming out. Do this a whole bunch of times and have a whole bunch of leads coming out, then wind and weld them together. Left side wires would make one lead, say ground, and the right side wires would make the other lead, say positive.

traditional pickups have many thousands of turns of very fine wire - connecting each turn in parallel with the rest would be extremely difficult to achieve. Even doing this with a sustainer driver of only 130 turns would require a huge ammount of work and be very difficult to do in a repeatable fashion.

This configuration could have several immediately obvious benefits. In general, this coil would last longer since, even if one wrapping got severed, the pickup would still work fine. It would (I think) only have one phase unlike todays pickups that have two. That would mean your pickups could never be out of phase with each other. I'm sure it would produce new sounds and coupled with standardly wrapped pickups, you'd have all sorts of neat possibilities.

traditional pickups last a very long time unless you seriously abuse them.

If it has two connectors it can be wired in two phase positions (if it only has one connector it won't do anything)

If it produced any sound at all, it would likely be a weak thin sound - most of the character and body of a pickups sound comes from its resonant frequency - this depends on its capacitance, its resistance and its inductance.... a pickup with many thousands of turns will have a high resistance (4000 - 17000 ohm) pickups above about 12000 start to sound 'dark' pickups below about 7000 start to sound very bright and 'cutting'... anything below 4000 or 5000 will probably need a pre amp and some sort of eq... Your parallel version would have probably less than 1 ohm (5000 parallel turns of 0.05 wire would be about 0.0002 ohm - basically a short circuit) means that if you could get any sound (using a huge pre-amp) it would likely be nasty. Of course, there may be ways to make it work with additional circuitry or novel components that havn't been tried before - might be a whole new field of pickup development...

I'm thinking this configuration might especially help with our sustainer project in curing certain ailments that EMI produces. I dunno, maybe it's worth something, maybe not. But with our driver only having 100-200 windings, it may be easy enough to test. Pickups have thousands of windings and may be more difficult. Let me know what you think!

How would it help to cure EMI problems?

If you believe this will work, pleases test it and report back to the group

NB you will need to design a custom circuit to test this idea - the LM386 poweramp is designed to drive a load of between 4 and 16 ohm (depending on the chip version). Your design will be a much lower impedence... e.g. using 0.2mm wire and 130 individual turns wired in parallel it will be roughly 0.0004 ohm... using the current circuit this just not work (or if your are really lucky it might fry the chip or fry the driver )

good luck and don't give up

Col

Edited April 9, 2007 by col

[Franky]

Hum that's a good idea!! It can sound great, or different... Let's hope it wouldn't need thousands of coil turns to be powerfull...

[Hors-Sujet] FlashBandit, is that you that registered on ThereminWorld's forum and posted about the SimpleTheremin project? Or are there several FlashBandits on the web? [/HS]

[Avalon]

Hi guys, just wanted to thank everyone for making this such an interesting project thread.

I've read quite alot of the thread and its been great insperation to try this myself, i've wound a driver on an old Fender Squire pickup bobbin (which works fairly well concidering my test guitar is on 8-38 strings lol), also built the Ruby-Fetzer, which seems to do the job nicely too.

My next step is to make some different drivers to see how i can get the best out of them (change the strings to atleast 10-46's too).

Once i get to a decent stage i'll start thinking about how to mount it all within in the guitar and pop up some piccys maybe of my progress.

Thanks again to everyone on the thread, class work

[Truth_David]

Lo del chillido es porque hay demasiada potencia por eso es importante una bobina bastante buena para que haga vibrar las cuerdas sin utilizar demasiada potencia, asi cuanto mejor sea esta menos EMI y por lo tanto mejor funcionamiento de todo el circuito.

Tambien debes comprobar dandole la vuelta a la bobina pues segun su posicion tendras mas chillido o menos, es decir la parte que pones abajo la pones arriba y compruebas.

Saludos.

Late translation.....Easter weekend, sorry all

The feedback is due to too much power, that is why it is important to have a pretty good coil which can cause the strings to vibrate without having to use too much power, so the better it is, the less EMI, and thus the better functioning of the entire circuit.

You ought to also check the effect of turning the coil around (180º? ed) because it will tend to produce more or less unwanted feedback according to where it is positioned. That is to say that you can try putting the coil the other way up and try it like that.

Cheers.

Hope this helps,

David

[psw]

Welcome Avalon, fantastic to hear that you got the thing working. Light strings are a problem especially the high ones as there is not so much metal for the electromagnet to work with. When making the driver, did you block up the bottom half of the bobbin? Anyway, great work and I'm glad the thread inspires!

A crazy thought just came to me out of the blue, and I want to know what you guys think:

Good to see that this stuff inspires thinking outside of the box and the project specifically. I am not sure that there would be any benefits, got to run now, but I will share some of my own crazy ideas at a later time...

pete

The feedback is due to too much power, that is why it is important to have a pretty good coil which can cause the strings to vibrate without having to use too much power, so the better it is, the less EMI, and thus the better functioning of the entire circuit.

Very well put!!!

Edited April 9, 2007 by psw

[Avalon]

Welcome Avalon, fantastic to hear that you got the thing working. Light strings are a problem especially the high ones as there is not so much metal for the electromagnet to work with. When making the driver, did you block up the bottom half of the bobbin? Anyway, great work and I'm glad the thread inspires!

Yeah i did mate, i never stray from a proven design lol, the main prob is really that the pickup bobbin has 6 pole pieces in, which im finding leaves gaps in the sustain (as i've seen discussed previously in the thread), so im going to try a steel core next, and probably try a couple of different designs too (the stacked coil humbucking driver looks interesting), but one thing at a time

And thanks for the welcome

[FlashBandit]

[Hors-Sujet] FlashBandit, is that you that registered on ThereminWorld's forum and posted about the SimpleTheremin project? Or are there several FlashBandits on the web? [/HS]

Yeah that's me. I've recently grown an interest in combining guitars and theremins, and so I decided to check it out!

EDIT: Oh, and I hope there aren't multiple flashbandit's, I think it's original.

Edited April 10, 2007 by FlashBandit

[FlashBandit]

Arrgh! I've built 4 or 5 drivers and all of them are horribly microphonic. I've potted with elmer's white glue, wood glue and gorilla glue. None of them seem to work (and gorrila glue gets every where and doesn't wash off ).

Here's how I wrap a driver: I lay down a thick layer of glue, smear it around, and just start wrapping. I wrap until the wire is no longer covered by glue and I then I lay down another layer of glue. I over wrap it usually about to 10 ohms, and start unwrapping it until I measure 8ohms. If any part is uncovered from glue, I'll put more in then just let it dry.

What am I doing wrong? No changes seem to work!

[psw]

As I gradually get myself re-established some things are starting to come to the surface. In relation to the sustainer I found the original driver that went with the "sustain box" which will be useful. Another thing is a TDA7052 power amp chip kit that I got to test this as a replacement for the LM386 device. It is a BTL amp with a potential power of 1.2W and may hold a lot of promise for our circuit.

What I'd like to devise now is a preamp with phase reversal and potentially control from a single rotary switch. The combination could provide for a very compact and versitile replacement for the Fetzer/Ruby solution for a basic circuit for this device.

If we could get the control down to a single rotary control this would avoid the need for permanent modifications to the instrument. In my guitar it may be possible to house the battery and poweramp in the trem cavity for instance and the preamp to the back of the rotary in the control cavity and a bobbinless coil mounted to the top of the neck pickup, hidden under it's cover.

Whatever the outcome, the TDA7052 offers a little more power, a simpler smaller circuit and the probable need only for a buffer in the preamp to stop loading. Getting a hold of this chip and the switching may be a little bit of a problem, but a standardisation of the circuit does offer some hope for a supply standard too, something that does seem to be needed.

To take the device a step further will require more development of the driver (say for a mid pickup solution) but we already have ideas for more sophisticated preamp/compressor circuits (see col's circuitry) that could be teamed with this amp module and plenty of inventiveness with the driver ideas.

pete

[onelastgoodbye]

Flash, the single coil drivers will always be microphonic to an extent, as in you'll get feedback and squealing when it's to close to the pickup. This is normal as you put quite a bit of power in there so don't worry about that. If it is microphonic in a way that you can actually hear the driver itself producing sound (buzzing), that is bad, and it means the driver is not potted well enough. Give the pva glue a day or two to cure completely and back off the power from the circuit a bit. You might want to pry open one of your 'failed' coils and I think you'd be quite surprised how loose the inner windings still are (at least I was with mine).

I tend to smear glue every 10 winds, and really push it in with a small plastic stick. It also helps a lot if you can clamp up the sides of the coil after winding (that's the key to making real compact coils). Maybe this can clarify that a bit:

Tim

[psw]

Arrgh! I've built 4 or 5 drivers and all of them are horribly microphonic. I've potted with elmer's white glue, wood glue and gorilla glue. None of them seem to work (and gorrila glue gets every where and doesn't wash off ).

Here's how I wrap a driver: I lay down a thick layer of glue, smear it around, and just start wrapping. I wrap until the wire is no longer covered by glue and I then I lay down another layer of glue. I over wrap it usually about to 10 ohms, and start unwrapping it until I measure 8ohms. If any part is uncovered from glue, I'll put more in then just let it dry.

What am I doing wrong? No changes seem to work!

Hmmm...you seem to be using the method I used. I did press the sides of the coil in to make sure it is tight and finished off with a few layers of electrical tape pulled very tight and clamped the top of my thin bobbin down while the glue dried.

You need to be sure about what you mean by microphonic and what is really going on here. Is the driver itself vibrating and emitting an audible noise? Or is it simply having an effect over the other pickups and the guitar in general. For instance, is it causing windings in the cheap single coils to vibrate and thus cause microphonic feedback? Is it a squeal that is emitted when the driver gets too close to the pickups, this is an oscillating feedback loop...

some things to consider... pete

[col]

Arrgh! I've built 4 or 5 drivers and all of them are horribly microphonic. I've potted with elmer's white glue, wood glue and gorilla glue. None of them seem to work (and gorrila glue gets every where and doesn't wash off ).

Here's how I wrap a driver: I lay down a thick layer of glue, smear it around, and just start wrapping. I wrap until the wire is no longer covered by glue and I then I lay down another layer of glue. I over wrap it usually about to 10 ohms, and start unwrapping it until I measure 8ohms. If any part is uncovered from glue, I'll put more in then just let it dry.

What am I doing wrong? No changes seem to work!

Are you sure they are microphonic ?

The squeal caused by magnetic feedback between pickup and driver sounds and behaves just like microphonic feedback - try just turning the gain of your circuit down until the squeal stops... This may cause the sustain to fail on the E (and maybe string... also see if moving the driver further from the pickup helps..

fwiw, a dual core driver almost eliminates this squeal issue - you just get fizz/fuzz/grunge

Also, although pete recomends pva (elmers) glue, I have used epoxy for my drivers. Epoxy will give a firmer finish and won't have the drying problems of pva but it is also toxic and difficult to work with. The most important thing is to get a slow drying one. Most of the off the shelf epoxy glues are super quick drying with a very fast and nasty chemical reaction as they cure - this means you don't get enough time to wind the coil(s) or for making adjustments and if you get it on your skin it will burn !

If you can find some slow curing epoxy, it will give you plenty of time to wind the coils, and also more time to wash if you get it on your skin !

The one I used is called Araldite 'Precision' this gives between 1 and 2 hours of good working time, and takes about a day to fully set. I also bought a bag of disposable latex gloves to protect my hands while winding.

(the dry epoxy comes off the gloves so they can be re-used !) also remember that epoxy doesn't stick to cling film and many plastics, so you can get creative with it...

cheers

Col

[onelastgoodbye]

Hey psw, just noticed you posted. As you may or may not be wondering I'm still struggling witth my agc circuit (which is the circuit zfrittz posted on page 153) unfortunately it didn't work the first time, so now I'm waiting for some stripboard to do some 'proper' soldering. I just hope i didn't already fry the tda7284, they're rare enough as it is...

I'm also busy working on the carbon guitar which has been a royal pain in the you-know-what so far (well at least I've learned a lot); so that's why I don't post that often.

Oh Col... I thought about sending you my spare tda7284yadayada as you mentioned (long ago) you had a hard time sourcing one...interested? I'll have to make sure I didn't fry the first one though .

Tim

[Truth_David]

As I gradually get myself re-established some things are starting to come to the surface. In relation to the sustainer I found the original driver that went with the "sustain box" which will be useful. Another thing is a TDA7052 power amp chip kit that I got to test this as a replacement for the LM386 device. It is a BTL amp with a potential power of 1.2W and may hold a lot of promise for our circuit.

What I'd like to devise now is a preamp with phase reversal and potentially control from a single rotary switch. The combination could provide for a very compact and versitile replacement for the Fetzer/Ruby solution for a basic circuit for this device.

If we could get the control down to a single rotary control this would avoid the need for permanent modifications to the instrument. In my guitar it may be possible to house the battery and poweramp in the trem cavity for instance and the preamp to the back of the rotary in the control cavity and a bobbinless coil mounted to the top of the neck pickup, hidden under it's cover.

Whatever the outcome, the TDA7052 offers a little more power, a simpler smaller circuit and the probable need only for a buffer in the preamp to stop loading. Getting a hold of this chip and the switching may be a little bit of a problem, but a standardisation of the circuit does offer some hope for a supply standard too, something that does seem to be needed.

To take the device a step further will require more development of the driver (say for a mid pickup solution) but we already have ideas for more sophisticated preamp/compressor circuits (see col's circuitry) that could be teamed with this amp module and plenty of inventiveness with the driver ideas.

pete

Hi Pete, I wish you success with that, it looks as if you are really onto something there. It would be great for all of us if you can pull it off, and if anyone can you can! Juán is almost through testing the re-vamped harmonic mode circuit. Apparently the 6v circuit is much more compact than the 9v one he sent me originally, so when it arrives I will post some picks (with his permission obviously). I feel that if at all possible you and Juán should team up with me as the translation intermediary if you like, because he has the electronics expertise of a professional - no offense, but it was his job, so he should be good at it. He is also working on a rotary switch option, although he still considers the micro switch to be the best option. I have been trying to imagine a way to make the micro switch work in a different context - after all, being a purely electromechanical device rather than an electronic switch, there is no reason why it should be limited to use inside a Strat type selector switch. One option I mentioned to him would be to actually have the micro switch fitted between the lever of the selector switch, actually in the slot in the pickguard, so that when the switch is used to select the bridge p/up it also simultaneously presses the micro switch. However that could easily crush the switch if the selector lever were moved too brusquely....but the must be quite a few other ways of doing this that we have not so far considered, and it would simplify things greatly if we could get it to work....

God bless

David

[FlashBandit]

When I say microphonic, I'm meaning that the actual coil vibrates. I've been testing this without even plugging my guitar in, and the actual driver coil emits a loud whistle. Someone told me that rubbing alcohol will soften the coating on magnetic wire, so I'm soaking 2 microphonic coils in alcohol. One was potted with elmer's wood glue and the other with gorilla glue. I'm hoping that the alcohol will soften everything up, and then I'll let it dry really slow so that the air bubbles that were released while soaking will fill up with glue. Cross your fingers

PSW + col, I've been reading about the recent advances with this project and I must say, I'm highly impressed. I want to help so, here's an idea that may help EMI. I've read that a humbucker-type driver helps eliminate EMI. I was thinking that the efficiency of said EMIBucker may be improved if you wrap the coils together. You'll set two cores close together in the same bobbin and then wrap them with wire making an "infinity" pattern. In other words, wrap one, then cross over to the other and wrap a coil. This will give you an "x" pattern in the center. The two coils should be phased opposite by doing this and the fact that the signal crosses one core then immediately the other, then back, may help localize/focus electromagnetic fields. That's just my 2 cents. I hope to try it when I'm done with finals (my university is ending a little early this year )

Edited April 12, 2007 by FlashBandit

[col]

When I say microphonic, I'm meaning that the actual coil vibrates. I've been testing this without even plugging my guitar in, and the actual driver coil emits a loud whistle. Someone told me that rubbing alcohol will soften the coating on magnetic wire, so I'm soaking 2 microphonic coils in alcohol. One was potted with elmer's wood glue and the other with gorilla glue. I'm hoping that the alcohol will soften everything up, and then I'll let it dry really slow so that the air bubbles that were released while soaking will fill up with glue. Cross your fingers

PSW + col, I've been reading about the recent advances with this project and I must say, I'm highly impressed. I want to help so, here's an idea that may help EMI. I've read that a humbucker-type driver helps eliminate EMI. I was thinking that the efficiency of said EMIBucker may be improved if you wrap the coils together. You'll set two cores close together in the same bobbin and then wrap them with wire making an "infinity" pattern. In other words, wrap one, then cross over to the other and wrap a coil. This will give you an "x" pattern in the center. The two coils should be phased opposite by doing this and the fact that the signal crosses one core then immediately the other, then back, may help localize/focus electromagnetic fields. That's just my 2 cents. I hope to try it when I'm done with finals (my university is ending a little early this year )

I have thought about this option - mostly as a version of the 'bi-lateral' type of dual core driver, but I couldn't come up with a satisfactory way to cope with the crossover point.. I'm not certain we're talking of the same thing... the way i conceived of this idea was as a single coil with a twist rather than two seperate coils... the twist combined with two oppositly polarised cores gives the EMIbucking ability.

The main problem is how to wind the coil(s)... how do you feed the wire through the gap considering that the bobbins are above and below... (I did come up with a crazy option as part of this thought process that would work, but if it did, it would be patentable and if it didn't, there would't be any point in posting it)

btw, 'signal' in a coil does not work as you are thinking - it doesn't just travel along the wires... it propagates accross the coil (by induction?) so that massive knot of crossing wires would probably cause serious inefficiency... still worthy of some experimentation though if your up to it

cheers

Col

[psw]

Yes Tim, still here, we must have posted at exactly the same time....

I love the way this thread inspires peoples ideas...

I think someone did make a twisted coil HB pickup, have no idea how they would have wound it or if it really had any benefit. One of the things about the dual coil designs is to remember that the coils should be around opposite magnetic polarities and reverse wound to one another, as in the HB configuration.

Really, a single coil simple design will work and for guitars with single coil neck pickups like strats is probably the easiest. Similarly, a simple circuit.

When I say microphonic, I'm meaning that the actual coil vibrates. I've been testing this without even plugging my guitar in, and the actual driver coil emits a loud whistle

Well, it does sound as if it is microphonics, but the guitar doesn't have to be plugged into an amp to produce feedback effects with the pickups! Is this whistle constant, indicating an EMI problem, or does it only vibrate when a string is plucked?

It can only make a sound, or at least should if it is getting a signal or feeding back with the pickups. If it is making a sound, then something is loose. The magnets might even be vibrating, or loose windings or even the core. I did wind some with a paper bobbin that glued itself pretty well to the coil with the PVA and had no such effects. My sustainer strat top bobbin made of thin plastic is showing the worse for wear and is quite loose (the glue does not stick to it) but the coil still works fine and holding up well, even though PVA glued...and no vibrations...

Also, although pete recomends pva (elmers) glue, I have used epoxy for my drivers.

Both col and tim use epoxy and I have some experience with the stuff. I really think the difficulty in working with it, the expense and the risk make it highly impractical, at least for the first couple of coils. As I say, mine have worked well with PVA, but I did make sure that the sides were well pushed in as I went and took care to let as little air between the windings as possible. The PVA will not fill gaps too well if they are any size. Be careful with the alcohol as if the enamel on the wire is stripped it could short out the coil. Heat tends to soften PVA and it could be that you could soften it up and apply pressure to the sides by heating the coil. This could be done by perhaps applying a battery to it so that the wire heats up a little, pressing the sides, then colling to set...just an idea...perhaps not a good one!

Switching is still an open topic and depends a little on application. With something like a strat with complicated bypassing and such, it could be done with electronic switching in many ways, but will need a hefty switch for most applications... Then there is the issue of drilling out the guitar to fit it. I am still open to a few different options and push button switching still has it's attractions. Mini toggles have worked well in my present guitar and held up really well, too...

Hope that helps and good to see the whole gang contributing still... pete

[Truth_David]

Have you read my post above? Here is the content again:

Hi Pete, I wish you success with that, it looks as if you are really onto something there. It would be great for all of us if you can pull it off, and if anyone can you can! Juán is almost through testing the re-vamped harmonic mode circuit. Apparently the 6v circuit is much more compact than the 9v one he sent me originally, so when it arrives I will post some picks (with his permission obviously). I feel that if at all possible you and Juán should team up with me as the translation intermediary if you like, because he has the electronics expertise of a professional (I remember you saying a while back that if we had any professional electronics techs in our team, the project would already be done and dusted, well we do, so why don't we make the most of his free contribution to the forum and his clearly altruistic attitude?!) - no offense, but it was his job, so he should be good at it. He is also working on a rotary switch option, although he still considers the micro switch to be the best option. I have been trying to imagine a way to make the micro switch work in a different context - after all, being a purely electro-mechanical device rather than an electronic switch, there is no reason why it should be limited to use inside a Strat type selector switch. One option I mentioned to him would be to actually have the micro switch fitted between the lever of the selector switch, actually in the slot in the pickguard, so that when the switch is used to select the bridge p/up it also simultaneously presses the micro switch. However that could easily crush the switch if the selector lever were moved too brusquely....but the must be quite a few other ways of doing this that we have not so far considered, and it would simplify things greatly if we could get it to work....

If you read the previous article posted on Juán's idea for the micro switch you would see that there really is no need for the complicated electronic switching you are still talking about. Admittedly his idea relies upon the use of a Strat type selector switch, but that is the purpose of my most recent post...

There has to be a way to employ the same type of micro switch which would not require the Strat type selector to work. As you never reacted as Col did - in his opinion this idea of Juán's was 'ingenious' - it strikes me that you must have missed the post. There was a photo of a typical Strat selector switch with the micro switch attached to one of the terminals so that it would be activated by the movement of the selector itself when switching the bridge pickup on, hence no electronics switching to worry about...

I feel that we should really combine forces to crack this and stop thinking in terms of complex electronic switching which is way beyond the ken of most people contributing to this forum, at least unless and until there is a integrated system available that could be mounted as a plug-and-play system.

As Juán reminded me, his brief as he sees it is to produce a system that only uses technology that is accessible to diy'ers and is easy to install on that basis. And this micro switch idea more than satisfies that criteria, whereas the electronic switching idea obviously does not, and has caused considerable confusion from what I have read so far. Using this option, your idea of minimizing everything to just one rotary switch becomes a practical idea and a reality - Juán has already done it, using the rotary switch for both the on/off and harmonic modes selection, then you just need a volume pot for the sensitivity.

The real problem aside from that still lies in finding a relatively unobtrusive way of getting the necessary cables connected between the guitar circuitry and that of the sustainer. I mentioned the possibility of a DIN connector with a computer type multipin cable - no one has followed up on this, but if you think about it this makes a great deal of sense. It would allow one to have a small D connector on the guitar itself, and run a perfectly flat cable from there to the project box, or if actually installed inside the instrument, to the sustain circuit. This would then make the system modular. If a small enough connector and cable of a similar type could be found, this might also be a key in implementing your idea of having a plug in modular circuit in the pickup itself (or even a plug in pickup combined with driver+mini circuit), if it still needed to interface with the guitar's own circuit, which I imagine it would need to be.

I realize that you are going through a difficult time and that you cannot possibly read all posts with the same attention, but my feeling is that you are skimming over some really important posts and missing vital information, whereas you are giving a great deal of time and attention to those who are not contributing much to the overall area of collaborating on the project in such a way as to really help to bring it towards a fully working system for everyone - here I am referring to those who clearly simply want to get a system up and working as quickly as possible for themselves, and these are not people who have contributed to the forum over lengthy periods as others have. And while we are all exhibiting an extraordinary amount of patience and goodwill, do you want to stretch the process out any more than necessary?

I have started to see Fernandes sustainers up for sale at around $199 - $400 and I have to admit to being sorely tempted to just go for it and have a working sustainer pre fitted to a good guitar without having to wait an eternity to be able to put it to musical use, and I daresay I would not be the only one. Why should artists like Steve Vai and his ilk be the only ones with creative access to this technology? And how long have such artists had these intruments? The answer is long enough to have been able to already master the technology as in its present state of development.....where does that leave the rest of us? I'll tell you - light years behind!!! I say this because, a sustainer requires a totally different technique, which cannot be learned without first having access to the technology, and that is a process which will take additional time before being able to use it effectively in a creative context.

You know, perhaps it would be useful to make reference to a philosophical theme here: 'time is the one thing that you can never give back or get back, however much you might want to....' thus time is priceless, so we need to be very careful how we use it.

David

Edited April 12, 2007 by Truth_David

[psw]

Sorry Dave, been really distracted and hardly able to fully read all this and take it in, let alone participate as I normally would...lot going on...

As Juán reminded me, his brief as he sees it is to produce a system that only uses technology that is accessible to diy'ers and is easy to install on that basis. And this micro switch idea more than satisfies that criteria, whereas the electronic switching idea obviously does not, and has caused considerable confusion from what I have read so far. Using this option, your idea of minimizing everything to just one rotary switch becomes a practical idea and a reality - Juán has already done it, using the rotary switch for both the on/off and harmonic modes selection, then you just need a volume pot for the sensitivity.

Yes, col has a similar thing with his 4 position rotary, but he has only one pickup. I was not able to have time, at the time, to really study the micro switch idea, but I didn't see how it would work for the bpassing and all. I found that I needed 4pdt to achieve all this, and at least all the grounds would still be connected thropugh the selector with this soulution.

It is one I used in a variation myself with the sensitivity pot on the tailpiece box idea. This idea was to use two microswitches behind the pot, as you pushed back on the palm of the hand or manipulated the pot, the switches would activate the system momentarily for touches of feedback here and there. Unfortunately two were not enough and the whole wiring into the guitar impractical, it did work (a bit of neoprene mouse pad as a washer to act as a spring worked really well) and maybe a useful idea for some other aplication some time (kill switch pot maybe)...

As I say though, I didn't really study it at the time, and the post flew by, perhaps you could find it and bring it back to the present...

As for a collaboration, more than willing, but at present I have not the time to do anything in the way of experimenting in a practical sense, but I am getting closer. The translating does make it difficult, obviously, and Jaun has posted some interesting stuff and obviously taken ideas like sheilding that little bit further than I was able to achieve...

As far as the preamp goes, with the TDA7052 amp, a buffer may be all that is required so anything suggested along those lines, preferably without trim pots for bias as in the fetzer, would be welcome. The other thing would be some way or reversing the signal phase at the preamp (rather than the driver leads) and I believe col had some ideas on how this could be done...

I like the microswitch idea, and position 4 on my new guitar is really not much use (humbucker bridge and middle pickup) having a weird tone, so sacrificing this for a sustainer selection would be attractive proposition. It is however I suspect problematic with a standard selector, would probably require a super switch and some kind of push pull pot for the harmonic mode.

So, got to run again, but appologies for not picking up on everything...very distracted... pete