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Hello again...just looking in after moving to my island...getting a bit chilly down here! Good to see the thread continues the tradition of long threads! Still...the computer didn't survive the mov

Excellent... This will be great, and I hadn't thought about that but the 4 ohm coils would take half the time and be easier to wind....alowing the use of quick epoxy like this...hope you wore rubbe

Hi,

yesterday I've found this thread and today I tried to read it, but my english is not very good. I've found two circuits and I'm not sure, if both will work for a sustainer. Maybe you can take a look at it.

Here they are:

Preamp

Preamp.gif

Amp

Amp.gif

For all people in germany: You can buy both at conrad.de.

Thank you for your support.

FoneBone

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Out of curiosity, how much did that cost to make? and how much does the sustainer itself cost?

You realise you could make a fortune with that?

Didn't cost much, the raw materials are maybe 5-10 $ at most. It's a lot of sanding and fitting though :D

As for making a fortune, it's up to PSW to decide where he wants to take this as it is sort of his project, I'm just trying to help out.

yesterday I've found this thread and today I tried to read it, but my english is not very good. I've found two circuits and I'm not sure, if both will work for a sustainer. Maybe you can take a look at it.

There's others here who know this stuff better than me (LK?) but anyway IMO they both seem useable; the second looks a bit excessive (complicated) although it does use the same opamp we've been using here for some time now. Could you post links to the exact items on conrad.de?

On another note, I've built a working sustainer! Prototype nr 4 covers all the notes from the low e up to the high e (!!), it doesn't squeel, it's really small and very easy to build ( no bobbins needed). plus i've developed this theory on why we've all been having so much trouble with the squeeling too. Pics and info 'll be here shortly, gotta sleep now...

Tim

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Hi , I'm new to this thread.

I had the idea to build a diy sustainer for a couple of years.

In jan '05 I build a sustainer circuit, it didn't work ,the last stage had little power

and sucked out batteries fast,and the strings didn't move,but the signal conditioning work was good.I though the notes should be shifted 90º degrees and they did.

Since then I think the driver is the most important thing to build and optimize.

I have been experimenting with pure tones with my sound card (has a powerstage that never burns!) (old isa soundblaster16).

For the A string (110hz) i need a tone of 55hz to drive the fundamental.

for the other notes, i always need half the frequency of the string to drive it.

This is because the coils cannot push steel,only can pull it (with negative or positive current) then the atraction is RECTIFIED.This converts a 55hz tone in a 110hz tone with harmonics.

To drive a string with its own frecuency i think you need to have a entirely positive or negative signal (to avoid attraction rectification), or use a somewhat complex cmos frequency divider to obtain a one octave less tone.

I saw your are using a rather simple amp circuit (sorry i read just 20 pages of the thread).How can you drive the fundamental of a note?

I have achieved to drive to fundamental tone of the A string (110hz) with a 1000hz and 2000hz tones (amplitude modulated at 55hz), 4000hz moved little.

The coil (a small one with just 1.3 ohms) did get too hot with a 55hz tone but

with 2000hz*55hz it just got warm and moved just a bit less.

I'm trying to guess the size of the coil, the gauge of the wire, nº of turns etc.

For a same size of coil there can be many versions:

thick wire and few turns , and thin wire and many turns. The latter is going to have more inductance, but more resistence also.In principle it's a matter of the voltage available to drive it. The second needs more voltage, the first more current.

But the second one has more inductance and can filter high notes (and may need too high voltage for a battery), the first

may send the energy straight to heat.In an AC transformer, the primary has

a inductance that stops the 50hz/60hz frequency with imaginary impedance.When the secondary is loaded , it somewhat sucks the primary magnetid field letting more current to pass.

A driver should be like that,aimed at the string probable frequency.

I also think that (although i would like a small driver) a big driver should be more

efficient, because a "upscaled" version of a coil may have the same inductance (same turns) but less resistance (being more optimal).

What do you think?.

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Could you post links to the exact items on conrad.de?

Amplifier 199613-62 6,95€

Preamp 195359-62 7,95€

Today I will go and buy this Amp... more to come soon.

FoneBone

P.S.: I didn't get it in the store, so I ordered it online. We will see :D

Edited by FoneBone
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just occured to me. since we have discussed driver impedance here has anyone thought of using one of those little ratshack transformer to help drive the driver more effectively. i mean they do freakin wonders for the lm386 to a speaker cab. alot better response than what i was getting straight. thought that might help.

ed

forgot to note its a 1k:8 ohm transformer

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Hi, I'am new here,

like eightstring, I would few month ago, build an ebow with these schematics:

Ebow schematics

but I didn't arrive to do working, so I'm happy to see that you have made this sustainer project.

Although that I read almost the whole thread, I have some questions:

1) what diameter of the enamel wire I have to buy?

2) What can I take for steel core?is it a magnetized core?, the thickness is significant?

3)what Preamp I have to build, Ruby, feltzer..?

4) Do the preamp need some modifications,and need to an harmonic switch and pots.

thanks

My site :SoundDIY

Edited by mathleflan
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woo lots of questions..

@ mathlefan: all "succesfull" sustainers that various people have built throughout this thread used 0,2 mm wire. I'v experimented with 0,3 mm, others with 1,5 mm, 1 mm,...etc; and we've pretty much established that 0,2 diameter wire really is the most efficient.

The core can be a steel rod, a ceramic magnet, little steel plates laminated together (think of the stuff they use for the core of transformers)...basically whatever you feel like using as long as it's magnetic. If you use a steel or iron core you still need a separate magnet of course.

I've been using ceramic bar magnets (from old pickups) and simply wrapped the coil around that because it takes away the hassle of sanding and filing steel. I didn't really notice a big difference in performance vs a steel core; the steel core does seem to be a bit more "focused" (the magnetic field doesn't stray away as much).

The core needs to be say.... 3-7 mm wide and as low as you can build it (something like 3-6 mm).

about the circuits:

- the ruby is a good all-round circuit, so that's your best bet

- the feltzer valve circuit (schematic is on the first post of the link) has more gain, so use that if you have low output pickups

- the little gem circuit doesn't have a preamp so you can (only) use that if you already have a built-in preamp, like with active pickups.

They don't really need any special modifications.

Keep in mind this isn't an exact science, so feel free to eperiment with other materials, makes, sizes. I've just tried to summarize what has worked best for various people.

@ ansil:

I believe RG alluded to using a transformer to change something (match impedance?) that would then change something something... :D . Also the very first sustainer patent thingy (was it Floyd Rose?) used a big transformer I believe. I think he was actually a standard pickup, but it had to be powered from the grid. At least it's worth exploring.

@ Fonebone:

You'd might have to make some adjustments to those circuits. Seems like the telephone amp uses a coil (Adapterspule) to pickup the sound from the telephone horn and amplify that. I *think* you basically have to remove that and connect your pickup there. The first circuit (preamp) might just be powerful enough on it's own (and probably easier to connect). I'm lousy with electronics though, so don't take my word for it! B)

@ eightstring

It's a lot of blind luck really.. we just take the bridge pickup signal, amplify it with an lm 368-based amp and send it through an 8 ohms coil made from 0,2 mm diameter enamel wire. And somehow everyone's experiments keep coming back to those values. I don't think you'd want to drive the strings with the pure fundamental; as a guitar string essentially vibrates at a mixture of it's fundamental and the corresponding harmonics. We're not just trying to vibrate the string, but to simulate the "natural" string behaviour and thus, feed it with it's own mixed harmonics sound. It might be worth exploring if the driver's ecfficiency would benefit from leaving out certain nth order harmonics or if it could be employed to improve the string separation of the hex designs. The hex drivers (separate drivers for each string) had a lot of problems with their magnetic fields influencing the adjacent strings...but that's a whole other can of worms, really.

I was intrigued when you said the coils can only push, not pull...can you elaborate on this?

@everybody

this is my latest prototype:

PICT0288.jpg

I just put it on top of the strings so you get an idea of the size. The core is a 5 x 5 x 60 mm ceramic bar magnet with 2 pieces of 1mm thick steel sheet glued to the sides of it; so the whole core is about 7mm wide.The steel is there to direct the magnetic field a bit more upward (well that's the theory). I actually wanted to make it a lot more narrow, but that magnet is a b*tch to shape :D . The clever part of the design is this: I doesn't need any bobbins! Since the core is magnetic I just stuck a small iron plate on top of it, and an identical plate on the bottom (I wrapped them in cellophane/ kitchen foil first); and wound the coil in between that, while adding epoxy onto the windings. If you're a bit careful you can just take off both plates after the epoxy has hardened, because kitchen foil is PE and epoxy doesn't stick to that! et voila...a bobbinless pickup.

The performance is excellent, and the only thing I want to try now is to make a smaller version, but other than that I think it's a keeper.

Anyway good to see this topic catching on again, and I hope psw returns soon, because I'm really lousy at long posts :D

Tim

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You'd might have to make some adjustments to those circuits. Seems like the telephone amp uses a coil (Adapterspule) to pickup the sound from the telephone horn and amplify that. I *think* you basically have to remove that and connect your pickup there. The first circuit (preamp) might just be powerful enough on it's own (and probably easier to connect). I'm lousy with electronics though, so don't take my word for it! :D

Hi onelastgoodbye,

thanks for your answer. So do you think I have to put the driver instead of the speaker and the guitar output instead of the the coil (Adapterspule)? Or do you mean the opposite? Sorry, but my electronic knowledge is very bad, as you can see :D

FoneBone

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thank you very much onelastgoodbye!

that's cool

I will buy a 0.6mm of wire, the smallest I can find..

For the steel core, I think I will take the core of a old pickup:

core.gif

I don't really undestand for the wire and core mounting.

you said "I just stuck a small iron plate on top of it, and an identical plate on the bottom (I wrapped them in cellophane/ kitchen foil first);"

In fact these iron plate is for put the wire easily on the Steel core?

I mad this little schematic, To know if I'm wrong

driver.gif

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@ FoneBone: Yes that's what I meant. The thing i don't know is how the circuit will react when it 'sees' the guitar output instead of the adapterspule...it might create problems, or it might not. You'll just have to try and see I guess. Anyway, if it doesn't work, don't be too afraid too solder your own circuit (the Ruby) it's really not that hard.

@ Mathlefan: Yeah, it's exactly like in the schematic, though the iron plates are bigger than that. They are about about 1 cm bigger than the core on all sides, so the coil wire can't slipp off while winding. Just don't overtighten the wire and make sure the plates don't slide off of the core.

I'm a bit worried that you won't get good results with the 0.6 mm wire, though. You'll have a really big coil if you want to wind it to 8 ohms ( a coil of 0.3 mm @ 4 ohms is about 50 % larger than a coil of 0.2 mm @ 8 ohms).

@ theblueark: I'm not sure yet, I think it might be best to shape them on a grinding wheel, as sanding them really doesn't take anything off and if you try to file them you tear these little pieces out. It's a very brittle material so be careful not to break them. Also watch out for your fingers.

Tim

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onelastkiss

I said the coil can only pull and cannot push.

Imagine two magnets,in north/south polarity they attract each other (what i call pull), in south/south or north/north polarity the repel each other (what i call push).

Now imagine an electromagnet,a battery,and a piece of iron or steel.

In a polarity the electromagnet will attract the iron, but in the reverse polarity it STILL will attract the iron.Thus the only option is to attract or not to attract,to pull or not to pull.

The iron piece is not a magnet, it can be only attracted.

The string is the piece of iron and the sustainer driver is the electromagnet.

Well, when you send a ac signal to the driver,the negative cycles will pull just like

the positive ones,so the the attraction force will look like the output of a bridge rectifier.Making the cycles to be twice as fast. Because of this,the string fundamental can be only driven with half of its frequency, and also is possible to drive the string with a high frequency modulated to half the frequency of the string.I previosly read in the thread someone talking about a patent talking about using a 40khz tone to drive the strings.

sorry I made a drawing but I have no webpage and cannot post it.

You told the hex drivers had problems with trying not to drive adjacent strings.

Anyways the problem should be less than a single big driver,isn't it?

ansil:

I think transformers are lame because they have a lot of problems,when managing wide bandwidth or high frequencies,but sure someone can go with it.

For higher impedance drivers I had I mind something like these:

http://www.geofex.com/circuits/+9_to_-9.htm

and or

http://www.geofex.com/circuits/+9_to_33.htm

Simply higher voltage available. (98% efficiency).

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Hi Tim...

There seems to be a fair bit of action here lately...very impressive stuff there...love the box as always.

And the magnet cored driver is fabulous...my thin driver coils have bobbins as thin as paper so they are virtually bobbinless, but I was never quite able to get by without something. That one is so neat.

I used thin plastic from folders and double sided thick cardboard to the top and bottom for support while winding so very similar. My coil is about 3mm thick. With a conventional bobbin that itself will double it's size and you got to make the thing so no bobbin is so much easier. You could mold the thing to any shape you wanted later in epoxy like the emg to keep it safe, assist in mounting and look super cool. No bobbin also allows the driver to be just that much closer to the string...or that little bit further away than one with a bobbin so excellent.

That german telephone amp LM386 with a transistor preamp stage looks just the ticket. Till my life got turned upside down I was about to abandon the LM386 for a new kind of amp chip that's clickless, etc. Still would require a preamp of some kind...but hey the old LM386 works but I know one could do just a little better.

The box idea and any others still have to address the guitar interface question...turning off the other pickups, selecting the bridge Pup and connecting the power. That's a fair bit of wiring...hmmmm.

The easiest would be a single pickup guitar or simply replacing the neck pickup with the driver and using the selector to turn on the driver...that would be really neat...

Thanks LK...hope to get some regular internet access in the near future and get my email back and talk to you guys but I am really proud to see this project still moving along and to have you guys continuing the enthusiasm...great stuff.

Anyway...good luck to everyone and I'll drop by again and check out some of the stuff I've missed (like the rest of the picks Tim)...

My Sustainer Strat is still going fine by the way and the project really is do-able. The driver really is the key...I fretted for the longest time over phases and driver modes but simple is best...0.2mm wire on a thin driver is a proven winning formula it would seem...it was a long road to get there, people needn't read the whole thread to find out how it was arrived at...but it does work with plenty of room for simple and creative experimentation...good luck all and thanks to everyone for keeping this thing alive...mnster thread that it is :D !!!

psw :DB)

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I said the coil can only pull and cannot push.

Wow...this is like the old days...I'll really have to check this stuff out a bit later when I've got a little time...I originally used a soundcard to drive the drivers teasting pure tones and different drive wave shapes and stuff...there are a few ways to drive a string including sending pulse through the string itself...and the hex idea is a whole nother kettle of fish...

The reason why the thin driver theory works so well is not really been fully explored...so stick around and maybe we can improve it...or at least understand it a bit more...sounds like some interesting debate could come from it...till then...psw

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I've spent the week reading this whole thread, till my eyes went all criss-crossed heh.

I am amazed at the amount of work and dedication you have put into your creations. Very impressed by everything.

Have you ever thought about working for some bigger company's Research and Development? Since the way I see it, you, like most diy guitarists, are more interested in finishing the creation than in owning the license and stuff like that.

Could this be a solution to many of your problems? You'll have access to more parts than you'll have on your own, you'll get paid doing what you're doing everyday now anyway, and although you won't have the license to the product, you'll probably be credited with the invention of it.

Would some kind folks volunteer emailing the more trusted 'ethical' companies and point them in the direction of this thread? I'm sure if they read through carefully they will see how dedicated you are and what a valuable employee you would make.

Some questions, of which I wasn't able to find the answers in the thread.

1) I got lost somewhere in the middle as to why you abandoned the hex x series drivers. Was it because of the string bending? Or was it that it is simply easier and that it works better in this magnetic coil method?

2) How do you split the signal? 1 goes to the driver and 1 goes to the output. Do you have a buffer before the split? I understand the Ruby amp circuit but I'm not sure how to connect it up to my guitar and still have an output to my output jack. It seems in Ansil's circuit, he just takes the output from the pickup and directs it into the amp. So pickup --> output and pickup --> amp. Won't that cause any problems? I always thought you had to have a buffer before any splitting of a signal, instead of just using a Y cable, or the signal would be weaker, and the the 2 loads will affect each other.

3) What will happen if we wind the driver like an inductor? As in coiling the wire around the width of an object roughly the length of our pickups and with the thickness similar to what we've been working with (3-6mm)

Like so:

simple2.jpg

I'm gonna participate in the experimenting once my exams are over, around the December period. Hope my questions aren't too silly :D

Edited by theblueark
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I did a bit more research and found these:

Kramer Sustainer

Kramer Baretta Infinity Sustainer

Japanese sustainer?

cont.jpg

02.jpg

04.jpg

jack.jpg

The Kramer Sustainer page has a manual for download and a schemetic on how to hook it up (not for how it works though). Apparently it's a humbucking sized sustainer and can work as a humbucking pickup also.

Edited by theblueark
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Those are my first drivers. Both have 8 ohms.

First was too thick, but second is only 4mm.

driver01.jpg

driver02.jpg

The tests with the telephone amplifier were bad, so that I will test another circuit.

Are there any mods of the fetzer-ruby circuit that work better than the original?

FoneBone

P.S.: Do you know any alternative to the MPF102/2N5457/J201? I don't find it at any store around me.

Edited by FoneBone
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The Fetzer-Ruby should work well exactly as originally drawn - the only addition I can think of that might improve performance is tweaking the caps to optimize the frequency response. As for the JFET, a BF245 is probably the closest European substitute, although if you have access to Toshiba semiconductors (which are reportedly fairly common in Europe), 2SK117 and 2SK170 are good possibilities as well. Any general purpose N-channel JFET with a Vgs(off) of .5 volts or less should work great. Keep in mind that JFETs by nature vary widely, even within the same manufacturing lot, so even with the trimmer in the circuit, you results will vary from one to another, so if you can't get the first one you try to bias out correctly, try another transistor or two until you get one that will work.

And if you happen to find a really good deal on 2SK170s, even in quantity, please let me know - they're scarce as hen's teeth over here, and priced accordingly!

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@lovekraft

Thanks for the alternative to the MPF102... I have used an BS170...

...and here it is:

fetzer-ruby01a.jpg

But I've got another problem... this little amp is very noisy... it hums and changes only the frequency of humming, if I use the potentiometers.

Any ideas?

Thx

FoneBone

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And if you happen to find a really good deal on 2SK170s, even in quantity, please let me know - they're scarce as hen's teeth over here, and priced accordingly!

There is the 2SK170 at reichelt.de for 0,47€.

As for the JFET, a BF245 is probably the closest European substitute, ...

Which version should I take BF245A, B, or C?

FoneBone

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