Introduction: 555Synth

This project was created during an Instructables Build Night (in collaboration with Jameco) at Open Garage. Using a 555 timer chip, a couple of synths were created, using different capacitor and resistor values. The project uses a variable resistor to change the synth pitch.

Step 1: Build the Basic Circuit

This circuit is heavily inspired by Bare Conductive's 555 Noise Maker circuit.

What you'll need
555 timer chip
9V Battery
9V Battery clip
Breadboard
A variable resistor (eg. conductive rubber, fabric or a potentiometer)
2 Capacitors (2x 1uF will get you started)
1 Resistor (1K Ohm)
1 Piezo speaker

Optional
LED
1 Resistor (220 Ohm)

Wire the circuit using the diagram attached. The LED was added to the circuit to see if the 555 was outputting something. Depending on the values of the capacitors and resistors, the frequency of the pulses the 555 chip generates can be too slow or too fast, resulting in pitches that fall outside of the human hearing range. The LED will visualise the pulses, just to make sure the circuit is working fine.

Step 2: Mod 1 : Conductive Rubber & Textile

A first synth was built using conductive rubber (we used this).

Specific components required:
Capacitors (1x 0.10uF, 1x 100uF)
Conductive rubber
1 Resistor (10K ohm) - depending on the length of the piece of rubber, you might need to add another resistor for a better effect.
Tshirt
Conductive thread

The idea of this synth was that it could be integrated in a tshirt, if you would pull the tshirt down - the pitch of the synth would change. Since the circuit is not too complex, it can be easily transferred to a tshirt using conductive thread (all you need is patience, and by the end of the project - you'll have greatly increased your sewing skills!)
For sewing the components, we used the Open Softwear PDF book, which has some very handy tips when it comes to sewing electronics.

Step 3: Mod2 : Potentiometer & Small Footprint

A second synth uses the same circuit as in the first step, using a potentiometer as an input. Turning the potentiometer increased or decreased the pitch. This synth was created as low piched synth (aka "the bass").

Specific components required:
2 Capacitors 100uF, 200uF
1 Rotary potentiometer (10K Ohm)

(Images of this one will be uploaded soon)

Comments

author
tkvaale made it! (author)2016-05-20

It worked great! Added a small button for convenience.

2016-05-20 22.42.33.mov2016-05-20 23.13.10.jpg
author
jomistinguett made it! (author)2015-07-01

Hi, I'm trying but it doesn't work. What is that blue small capacitor in the pictures? Couldn't find in the list.

author
DriesDR made it! (author)DriesDR2015-07-01

Hi there, the small blue one is a ceramic capacitor of 0.10uF. Compared to electrolytic capacitors, ceramic ones are not polarised - if you're using electrolytic ones, make sure to put them in the right way. Hope this helps!

author
jomistinguett made it! (author)jomistinguett2015-07-02

I'll try! Thanks!!

author
Shortcircui made it! (author)2014-08-21

this actually works really well. I tried it on a breadboard and it worked fine, but I just tried putting it on a stripboard and it wouldnt work. any hints?

author
DriesDR made it! (author)DriesDR2014-08-21

Hmm, odd. I only made the circuit on breadboard, I should think moving it to stripboard shouldn't cause any issue when all connections are the same.

author
Shortcircui made it! (author)Shortcircui2014-08-22

I got it working again, after desoldering everything. rebuilt on a breadboard and took a few attempts to get going, but it works again and I am happy to say that I havent damaged any of the components with my rubbish soldering skills. therefore, the problem is either rogue solder joints, bad joints, or the scratched off copper under the 555 itself wasnt properly scratched off. any thoughts as to how I might go about putting it on a stripboard properly. btw, I am only 13, so solutions within my price range would be helpful. thanks!

author
Shortcircui made it! (author)Shortcircui2014-08-23

and it turns out that you can run this without the 1uf capacitor

author
Shortcircui made it! (author)2014-08-16

What sort of effect would a 50k potentiometer have on the pitch?

author
DriesDR made it! (author)DriesDR2014-08-17

If I remember correctly, increasing the resistance in the circuit caused the pitch to go down. I'm not sure what a 50k potentiometer would do, but if you try it and don't hear anything the sound is probably too low. If that is the case, try replacing the 10K resistor with something a lot lower.

In the example with the conductive rubber, my maximum resistance was about 3.5K ohm.

author
Karol Kagan made it! (author)2014-05-23

Great! Really easy for beginners, and I love how easy to modify it is!

555synth.jpg
author
slader166 made it! (author)2013-12-05

Where do I find a 1uF capacitor? The closest I can find is 0.1uF.

author
aalejo made it! (author)aalejo2014-02-04

my friend it a ceramic caps the brown round 103 is 0.01uf the 104 is 0.1uf

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