Infinite Guitar Sustainer




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Today we're making a three-string guitar sustainer that fits under the strings like a guitar pickup.

This sustainer will enable any guitar to hold out a note infinitely long, achieving that rich, violin-like, sustain sound.

The principle behind this sustainer is the same principle that has been used by many popular guitarists such as Carlos Santana, Joe Satriani, and Steve Vai; a feedback (magnetic flux) is used to vibrate the strings, creating a sustained sound.

Step 1: Watch the Video!

Click here to watch on YouTube

Check out this quick video to see the sustainer working and hear how it sounds! It also guides you through the steps below from start to end.

Step 2: What We'll Need...

Here is the list of materials we'll need:

  • 6x 42 Ohm Passive Buzzers
  • 2x 1/4" Mono patch cable (one 4ft. and the other 1 ft.)
  • 1x Paper Protoboard
  • 1x 1/4" Mono panel jack

We'll also need our Tin Can Amplifier from our last project (a palm-sized amplifier that runs on a 9V battery).

Where to buy



Step 3: Prepare the Coils

We'll start by turning our buzzers into our sustainer coils.

Using a sharp blade, carefully shave off the cover of the buzzer, by working the blade around the groove of the buzzer.

When we remove the cover, we'll find our coil inside, as well as a metal piece that's responsible for making the buzzer sound.

We don't want our coils to produce any sound, so we can simply throw this piece out or glue it on top of the coil (so that it won't vibrate but will protect the coil from damage).

Step 4: Align the Coils

After we have our coils prepared, we'll start aligning them on our paper protoboard.

Keep in mind that the sustainer we're making goes under the top three strings. We'll need the strings directly above the center of the coils.

Just be sure to align them under your guitar first so that you know where to place them on the board.

We'll remove any excess board space by scoring it with our blade then snapping it off.

Then, smooth out the edges of the board with sand paper.

Now we're going to put our coils back in place. Note that it's important that we keep the polarities (positive and negative terminals marked on the back) of the coils in the same direction.

Step 5: Glue the Coils

Next we'll add a dab of super glue under each of the coils so that they stay in place.

Leave to dry before proceeding.

Step 6: Solder the Coils

Once the glue dries, we can bend the pins of the coils on the back of the board. We're doing this to reduce the height of the sustainer, so that it fits easier under the guitar strings.

We're going to have to solder the positive terminals together and the negative terminals together, so bend the pins in a way that minimizes soldering distance.

When we're done soldering, we can check the integrity of the joints by measuring the resistance between the positives and negatives with a multimeter.

Since we have three 42 ohm resistances in parallel, we should be reading around 14 ohms (since 42/3 = 14).

Step 7: Repeat

We'll repeat the procedure for the second row of coils.

Step 8: Solder the Cable

Now we'll take our 4 ft. 1/4" mono patch cable (I'm actually using an 1/8" cable with 1/4" adapters in the picture), and cut it in half. Then solder the positive and negative ends of the cable to the positive and negative terminals of each set of coils.

Step 9: Add Height

Since the middle string of the guitar is a little further away from the fretboard than the top string is, we'll need to attach a piece of popsicle stick to the back of the middle string coils so that it puts the sustainer on a slight slant, bringing the middle string coils closer to the string.

Step 10: Install the Sustainer

Now we're ready to attach the sustainer.

Loosen the bottom three strings, but keep the top three strings tight. We'll temporarily hold the sustainer in place with a bit of duct tape.

Make sure that the strings run directly across the center of the coils, and that none of the strings touch the coils when the strings are played.

We'll add a dab of hot glue under each of the four corners of the sustainer to set it in place.

Once the glue dries, we'll remove the tape.

On the back of the guitar, we'll need to add a dab of hot glue to hold down the sustainer cables. This will relieve the solder joints of any stress from the cable moving around too much.

Step 11: Add a Dry Signal Jack

** This step will require a small modification to the volume knob (potentiometer) of the guitar, and will create a louder sustain. It is possible to use the sustainer without this step (skip to next step).

We'll need to add a dry signal jack (a signal that is unaffected by the volume potentiometer) to the guitar. To do so, we'll have to access the back of the volume knob.

This guitar opens in the back, but most Strat-like guitars will open in the front.

After we open the plate, we'll see that our volume knob has three legs (refer to picture). We'll need to extend the input and ground pins, which are the leftmost and rightmost pin, respectively, to our new mono jack.

We'll solder two pieces of loose wires to those pins, and cut a hole through the back plate, so that the mono jack can sit on top, with it's panel connections exposed through the hole.

We'll glue the jack in place, then solder the signal and ground wires to the respective terminals of the mono jack.

Afterwards, we'll just screw it back together and we're done with the dry signal jack.

Step 12: Secure the Tin Can Amplifier

Now to hold the tin can amplifier in place, we'll use two strips of velcro.

Attach the soft side of the velcro to the guitar and the hard side to the tin can amplifier (we do this because the hard side of velcro will stick to clothing and we wouldn't want that on the back of our guitar when the tin can amplifier is not in place).

And we're done!

Step 13: Plug It In!

For self-sustain mode (does not require dry signal jack, but produces weaker sustain), one sustainer jack goes in the input of the tin can amplifier while the other goes in the output.

And for the dry-signal mode (requires dry signal jack, but produces louder sustain), we'll join both sustainer jacks with an adapter and plug that into the output of the tin can amplifier. Then our foot long patch cord connects the dry signal to the input.

Step 14: Turn It on and Give It a Test!

Turn on the can, plug in the guitar, and give it a test!

Check out the video attached above to hear how the sustainer sounds in action (and a comparison of the two modes)!

If you liked this project, then don't forget to share it with all your guitarist buddies.

Perhaps you'll like some of my other music related projects too - you can check them out at my YouTube Channel.

More cool projects coming up - see you next week!



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    30 Discussions


    Question 4 months ago on Step 14

    Soooooooo? Just wondering why 6 coils and not just 3? Is it different or is it just because you have only one pickup?


    1 year ago

    anyone out there to help troubleshoot this?

    I made 3 tin can amps that work great.

    I made 3 buzzer chips and none work! I get only feedback.

    1 reply

    Reply 1 year ago

    Same problem here. If the amps work but the buzzer unit doesn't my only guess i something is not wired right or maybe the wrong buzzers.


    1 year ago

    This is an excellent instructible. Kale put a lot of time and effort into making this and the video. And for that thank you very much. There is, however, one small detail that would have been nice to know. R.e. the buzzers he says bend the pins to make soldering easier. Well, if you install the buzzers with the pins lined up in a nice, neat row, left to right or vice versa you will never orient the pins in the manner that obtains the beautiful soldering pattern he performs. I discovered that AFTER I glued the buzzers down. Look at his pictures VERY closely.


    1 year ago

    This is a terrific project. Thanks. I have a possible idea for another project you might consider designing, an audio cable tester. Every guitarist needs one.


    3 years ago

    just get a Sustainiac. you won't have all that stuff hanging out the guitar

    3 replies

    Reply 1 year ago

    Lol. You also spent 150 bucks for the sustainer and another 100 bucks to have it installed. This gizmo by Kale is 10 times cheaper.


    Reply 3 years ago

    Although you do have a point, i think you are missing the point of this web. No offence


    1 year ago

    In your video and Instructible I see three different types of mono
    jacks. I have the 3 pin mono jack seen in the picture of Step 2 of the
    Instructible. How do you determine which pin on the jack gets the
    signal lead and which pin gets the ground lead from the volume pot.? I
    think that the first pin on the mono jack is the ground but I don't
    know which of the other two rearward pins gets the signal.


    Question 1 year ago on Step 1

    In your video and Instructible I see three different types of mono jacks. I have the 3 pin mono jack seen in the picture of Step 2 of the Instructible. How do you determine which pin on the jack gets the signal lead and which pin gets the ground lead from the volume pot.? I think that the first pin on the mono jack is the ground but I don't know which of the other two rearward pins gets the signal.


    Question 1 year ago

    Just out of curiosity, do you think it would work for top thee strings?


    1 year ago

    I have a question. It might be a stupid one. Anyway, I'd be very glad if
    someone can answer it: Why don't the rest of the strings sound when one
    of them is being sustained? If all three electromagnets are connected
    to the same output, shouldn't they all activate at the same time?

    1 reply

    Reply 1 year ago

    it takes great “dampening” with fret fingers and strum hand I presume. But what Might be true is the electromagnetic field will bounce off a vibrating string, where a still string has no fight against it.


    1 year ago

    I have a few spare pickups laying about. Couldn't I use one of those turned sideways instead of using the buzzer pickups?


    1 year ago

    I'd buy a $30 ebow knock off.


    1 year ago

    Hi Evan, What happens if you plug in a keyboard into the mini amp and simultaneously play the same note? Do different sounds change the tone of the guitar? If so, it could make a clever little built in guitar effects that can also work on acoustic guitars... Detect frequency, play the corresponding midi note, amplify the output sound into the mini amp and boom, endless guitar effects! (If it works)


    2 years ago

    Really interested in this project, however due to scarcity of resources due to my location I wanted to omit the tin can amplifier part. So I'm looking for alternatives (which will be cheaper and a lot more tidy) and my question is; Can I use a lm386 amplifier module like in this pic? If so, can u help me out with the schematics pls? Anyone?


    3 years ago

    Thx for a nice ible. However I have to ask why we need 2 row of coils when using the dry signal jack. Does it work w just one row??