Introduction: Infinite Guitar Sustainer
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!
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
- 42 Ohm Buzzers: http://amzn.to/2dHqdnx
- 1/4" Mono patch cable: http://amzn.to/2dPQWdy
- Perfboard: http://amzn.to/2cQcN7q
- Mono panel jack: http://amzn.to/2dPR3Ws
- Weller WES51 Analog Soldering Station: http://amzn.to/2dq7Q4m
- MG Chemicals Silver Solder: http://amzn.to/2dHj0nq
- Helping hand: http://amzn.to/2dc553O
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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Please be positive and constructive.
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.
Just out of curiosity, do you think it would work for top thee strings?