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How To Make A Guitar Sustainer System, Tutorial

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I have some problem with fetzer/ruby and don't know some things.

I use Diy fever Fetzer/Ruby circuit diagram but don't understand these:

1. Why the are two ground in circuit?

2. Where i put battery ground, to the circuit ground?

3. I have loud awful voice when not batterien on.

4. i don't understand which one is Transistor J201 source and drive? i know where is gate. Source goes 1M? and drive goes condensator?and trimmer.

5. Is it problem if i have 9ohm mic winded?

Help me, i know u understand.

-Ari, finland.

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Welcome Ari...questions like these are best posted on the main thread in the electronics section...there is a link at the end of the post. Have replied to your PM...welcome aboard!


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Below are some entries from the Sustainer Thread recently. These show another variation of the basic project, an alternative circuit and two great sound/video clips of the device in action to give people an idea of what can be expected with care and attention to detail.

Excellent work by Strib...

Hi there !

Tests passed successfuly

I've built 2 preamp/opamp to do my tests :

- first fetzer ruby, which was not loud enough, because of the lm386 N1 chip (only 0.7w).


As I was almost sure about the driver, then, I managed to build another amp, based on a LM741 preamp and a TBA820M opamp.

The difference between the 2 circuits is very important, with only one pot for the gain, here it is :


This is a prototype, I've now reduced the size of the PCB to 5cmx3cm . That will allow me to install it directly into electronic cavity.

I've built 2 differents drivers, the first one with a piece of planer blade, 2.5mm thick :


The second, made from transformer scratched :


I first ued a ceramic bar from an old single coil, but the sustain was not very accurate, especially on the G/E/B strings (because of the diameter of the chords), then I replaced the bar with small square neodymium magnets (6mmx4mm 2mm thick), and this solved the problem.

My old rusty guitar is now ready to cry :


Here are 2 divs movies during first tests :

fondamental mode

harmonique mode

Sustain forever



Hello !

Both drivers look fantastic and the circuit very professional...the proof of course is in the sound clips, the harmonic one a particularly like...nice control for just starting out playing with the device, good technique!

Thanks pete :D

Now of course people are going to want to know more about these circuits, especially the second one. Are you prepared to share? I am surprised that the F/R wouldn't work but I do think there are limitations to the design, using an op-amp for the preamp allows for a lot more control over the gain and so allows adjustment for the guitar.

Of course I'm ready to share. The opamp/preamp come from the bobblick pages, he has developped this shematic

(It can be publied in DIY projects, I've contacted him for the autorisation, that he nicely gave me. I thank him again)

Then, I took the typical application of the TBA820M included in the datasheet :


For making these schematics and PCB :




(these are optimized for fitting into electronic cavity. This is the same circtuit you can view in my last post. => 400DPI images, print them at 25% scale)

Normally I would have suggested that more magnetic and amplifier "power" is perhaps not the best idea...but it seems to have worked for you. In the circuit, are those LED's a clipping circuit or indicator lights...again, clipping has proven not to be such a good idea, but then maybe it provides some compression that is working for you creating a limiter effect. I guess the proof is if you can play the guitar completely clean with the same control.

There is no more magnetic with the little neodymium, just a balanced magnetization of the bar. I've put 2 little magnets for the E/A/D strings, and 3 for the G/B/E .

The leds are supposed to act as clip as you said. The problem I have, is that I must decrease the gain for harmonic mode, because I have an EMI noise if I switch with the same level than fondamental mode...

Must solve this with a larger pot I think.

I'll try to developp a little bit more the system this week end, before thinking about finishing the installation :D

If you need more informations, feel free to contact me B)


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Hello from Barcelona!!!

this is Michel Miralles,spanish luthier from Barcelona.I make custom guitars,exploring new chances tecnollogy gives us.

The Open Source meaning aarived to guitar making when i transplant Line 6 Variax electronics to my custom guitars,feating Fernandes Sustainer,MIDI systems anf things like this.All this toys are closed.One day,really one night...I brocke accidentally a coil from the Fernandes Sustainer circuit.Can you imagine next?nobody,the dealer,the company,nobody could tell me what king of coil was,an replace this.It was secret...I had to pay another Sustainer,,,Finally I resolved the problem,Line 6 make a secret too of the Variax circuit,and nobody can replace or repair anything.You don t buy the toy with his information,you buy the toy for only a time.Finally you have to go the company for a new product or the official dealer.

Im very happy with your project.Fernandes Sustainer is great but too expensive,and the best is than this is than we can make it better.

I will began now your project,but I haven't found the schematic.Is there the same configuration than the Fernandes Sustainer?two switches,one intesity pot?

last thing,excuse my english ,I feel speackin like an indian guay on a western...

thanks really

Michel Miralles




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Hola Barcelona!

This is the tutorial section...there are some circuit things available in the first post here...however...general or specific questions need to be directed to the main sustainer thread...HERE

Your My Space Page says that you professionally install and modify sustainers and variax systems and some picks of a couple of very nice guitars so I would expect you know more about this kind of thing than me!

The DIY sustainer is not the same as the Sustainiac or Fernandes systems and so will need specific information about how you have broken the driver coil. These things are not designed to come apart and this would appear to be the only way it could be broken in this way.

If you mean the transformer on the fernandes circuit board, I am not sure what this is, but there may be numbers or means to measure it and replace it. Again come to the Sustainer thread to discuss such questions.

The DIY sustainer circuit is a much simpler design that works only with drivers designed for it...the driver or the circuit can not be used to fix a fernandes system.

If you are planning on building your own, you will need to do some reading.

If you are planning to make your own for sale through your guitar business, this is forbidden...these ideas were developed by myself and a lot of members here as an alternative DIY method of producing a similar effect and not as a commercial undertaking. Many have tried to take the ideas and make them their own over this time without having the understanding to make it work properly and then promote it elsewhere and failed.

Please post at the main Sustainer Thread after reading this tutorial and other threads linked below...

welcome...pete :D

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Here's an idea for the mounting of a sustainer unit:


Basically, place it in the fretboard where the end of the board would usually go. Genius!

(obviously, the nanomag isn't a sustainer, but I think it's possible to make a sustainer unit small enough to fit into that size area)

Edited by Prostheta

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Interesting...I am not sure why epiphone thinks you can get an acoustic sound out of another "magnetic" pickup by using rare earth magnets and placing it in that position...I would have thought a piezo would be the only way to really pickup anything but the strings vibrations...ehhh

This kind of end of the neck placement has been used on acoustics for a long time (John Lennon's Gibson acoustic comes to mind) and might be able to be adapted...


Since I am breaking my rule in adding to the "tutorial" section and thus risking a huge tutorial thread in response to the even huger sustainer thread (see previous post :D )...


Above is my latest driver...a surface mounted very compact coil on a telecaster (vote for it next month in GOTM...and see the links below...)

The "rail" in the core needs to be as wide as a fret so the added coil makes it just a little wider again. It would be tricky to get it exactly the width of the fretboard...the end winds will obviously add to that.

After much experimentation and perhaps even more discussion and debate...my design of a thin coil (in this case and generally 3mm deep)...is very important to the working of the device.

In more recent times I have been working towards pickup adaption coils to produce this...



A wafer coil to convert a strat sized pickup of choice to a sustainer driver to make a pickup-driver with very low mod and visual impact. Both these, and to a lesser extent the driver above rely on my epoxy winding machine...so difficult to DIY (though I could see with care something like the tele one could be achieved)

There may be some exciting news on the wafer coil thing in the near future...and the possibility of my circuit becoming available...

An idea that I have always liked was the possibility of making an HB ring that included the sustainer coil in a larger neck side portion. Another option would be to build an HB out of a rail or SD jnr and put a driver next to it in an HB sized hole and ring. HB drivers (as such) have not really been explored...

The idea of using rare earth magnets has often come up...but generally not suitable. I tried it again on the first version of the tele but it adversely affected the strings natural vibration even when off. However the ceramic magnets used were only 3-4mm thick. I could see some benefit in shaping an alnico magnet from an HB perhaps and remagnetizing it after cutting and such has adversely affected it.

On a custom instrument...I dare say a little ingenuity and experimentation should be able to produce something pretty stealthy and the success of the tele driver shows the potential for the thing to be very compact...a recent member wound something very similar by had with the wood glue method (see main thread), much to my surprise taking the tele driver as an inspiration.

I am very proud of the tele driver as it's transparent construction shows more clearly exactly how simple and compact the thing can be and seems to be encouraging more people to try this stuff for themselves...


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Thank's for your answers.

I design and build electic guitars,and I thought it would be great use "open hardware".That's a one man project, that's not a company, I'm musician, and I work in a retall space where I have the workshop. I know about Open Source philosophy.That's the reason why I only use Linux based software, and the reason why finally I make my own instruments.I use Fernandes Sustainer for the last years,and I would like make my next instruments wth a system similar.I do the same with Variax Line 6.I buy the guitar,take out electronics,and feat inside my guitar.Like buying Fernandes Sustainer or Seymour Duncan pickups.There's no relation betwen us,but I don't have the "source code",they are clossed.I would like to use an open schematic,making refernce the original source,designer and original lisence.I don't wanna sell this,one by one,only make this for my guitars.And maybe sell this one by one,with your schematic inside.I think a Creative Commons lisence would be great.

My new instrument will feat "sustainer",Variax,midi output,and maybe some led on the fretboard... i restart guitar making now,I stoped this for the last years.My production I hope will be 2 instruments by year.That's more an artistical workshop. I think it's not a good idea only use open conocimiento de forma privada,.This is like professinal suport for open software, like Linux.

I send you some links of some new open products



I hope you will understand the reall meaning of this mail,and excuse my horrible english

thanks for your time


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Hello Michel!

Try going here BIG sustainer Thread, this thread is not up to date.

I am currently working on a "Creative Commons" schematic that I will release on the forum. It is a simple and standardized little circuit that is not at all hard to build if you have some soldering skills and knowledge of electronics. PSW is helping me out with it, and I think it will be a really solid design that will help get people like you up and running.

Although PSW's really advanced circuit will remain secret and be for sale from him soon, my circuit will be freely availible here as perfectly functioning sustainer amp. It just will not have the really advanced features in it that PSW has spent years and lots of $$$ developing.

So be patient -- hopefully I will have time to test my circuit design and then post it here soon!

Edited by mrjstudios

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That Coyote is the most awesome thing I have ever seen.....who would have thought that open source capability would be brought forth to instruments? That's like Line6 offering out a public API to modelling....awesome!

I would however recommend introducing this to a seperate thread.

Michel - your English is cool, but if you need a translator to get across what you need, then I'm sure the mod team can help you out.

Hell yeah.

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You will note though, that these things are not strictly "open source"...you still have to buy the hardware for these things. Not bad, but the open source bit is from people programming effects and such...Line^ allows this too with their workbench modeling tools...

All the information to build your own sustainer is provided here...but not for people to make a profit from it so much...and certainly the intention is that people will contribute to the project itself rather than simply copy it to sell guitars with.

As MSJ says, there are circuits and he is working on updated version and I have decided to sell limited copies of my own circuit at a very reasonable price in the near future. However, this more developed miniture circuit is not for open source as far as the details go.

Anyway...more than welcome, but this is the tutorial thread...post over at the main thread linked above and or below and a whole bunch of people may be able to help you and leave this one to the more tutorial aspects and save it getting too big also :D


PS...you wouldn't be "billyluthier" from the GN2 forum with a similar proposal?

PPS...also, check links in my signature below for more details about my designs and stuff

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