Here’s an explanation of how the circuit works:

The circuit gets divided into four sections, A through D.

Section A does some basic regulation to the waveform, first normalizing and then amplifying it, as shown above… Nothing too significant, just some basic preparation for the rest of the circuit.

The second stage uses two diodes to divide up the positive and negative peaks of the wave, and separates it into two channels.

Section C does two things- first, the negative peak band is inverted, meaning both waves are positive. You can see that the two hold (roughly) the same voltage.

After this, the waveforms are mixed together, and we can see we finally have 440 Hz, twice the Hertz value of our input- in other words, a full octave! This works due to the way that waveforms work- When the negative peaks are set to positive values, the amount of pulses (the frequency) is effectively doubled.

All that’s left is section D, which normalizes the waveform and shapes it to look (and sound) something like the input.

Problem: There isn’t an outlet in the hallway. (And it’d be inefficient to plug and unplug the lights anyway, even if there was)

After some thinking, I came across the idea that, since the light bulb plug uses the same voltage as a wall outlet, what if you could just make an adapter of sorts? And, once made, you could plug in the lights, and turn them on/off directly from the wall switch!

Shortly afterwards, I started in to making it, and finished it in about half an hour.

Final Product:

Once made, I replaced this (crazy) contraption with the overhead light bulb, plugged in (and hung) some Christmas lights, and tested it out! Luckily, it didn’t explode, short, spark or injure! (I don’t have a photo, but take my word that it’s there)

Spared from laying about parts, I’m honestly amazed that in this case, form met function, and that it fit together so nicely.

Anyhow-

Cheers to the modders/scrappers/rappers/and builders,

Secoyatree

A vocoder, put simply, is a device that filters an audio input (typically a microphone) in accordance to a second input (usually a keyboard). This is done by feeding the first source (the “Program”) through a series of ‘band-pass filters’– or ‘bands’ for short. Once the first input is separated and decoded, the second input (the “Carrier”) is analyzed and processed with a circuit to provide the amplitude levels for the program (An “Envelope Follower”). Finally, this spectrum of signals are mixed and re-encoded to a single output.

The vocoder adds a synthetic, artificial tone to the voice, as if the words are being spoken through a robot or an early voice module.

Here is one that Kraftwerk had custom built for them in the ’70s (and used in the album “Ralf und Florian“)!

The vocoder we will be building have a total of 14 bands (each separately adjustable in volume), optional mono or stereo out, and LED readouts for the levels of each band! The stereo effect is done by sending the odd numbered bands to the left channel, and the even ones to the right.

The page where the info on this specific vocoder may be found here, mind you, it’s only for reference- I merely retrieved the schematics from this page, along with a bit of miscellaneous data.

I have ordered the parts for it off of Tayda electronics roughly an hour ago, and the package should arrive in a week! (Over 500 parts- the soldering will be mind-numbing…)

Here are the schematics for this thing:

This is the amplifier for the “Program” input (With option for Mic Jack, or regular patch cable):

And for the “Carrier” input:

This is the combination Band-Pass Filter and Envelope-Follower Circuit. This circuit will be repeated 14 times, but each time will have different values for the capacitors marked “C”, value chart is up next.

And now for the values of the filter capacitors (a.k.a. “Condensers”):

Filter Capacitor Value Chart

After all the algebraic fun of spectral decoding, we finally get to the mixer, where the re-encoding happens!

So, however ambitious it may seem, the “output” of this project will be very much worth it!

This concludes today’s post, and once again,

“Weird sounds abound!”

–Secoyatree

That’s the complete schematic for it (so far). I’ll try to explain how each part of the circuit works…


This circuit is simply an amplifier… It takes the input audio, and feeds it through the circuit. It’s wired up to work with audio current around 0.5 volts, the standard output of a bass or guitar. The component at the beginning is a volume control, in case the input source is already amplified… Cheap, I know. But on to the next bit!

This part uses a 555 chip, a timer circuit. In this case, it produces the rate at which the tremolo runs. A range of about 1 to 17 Hz can be achieved with this. All the way to the right you’ll see a separate input source, as well as a switch. This is so the user of the device could also add a ‘carrier’ signal, allowing them to use a different oscillator.

The left circuit acts as an amplifier, only this time for the oscillator. This is just in case the user input goes below the 5 volts that the rest of the circuit operates under. The round component all the way to the left is actually an LED, which would be used to indicate the status of the oscillator. An almost identical setup is used to amplify the final output (shown on the right).

This segment is the actual tremolo! What it does is take the input source (the ‘minus’ pin of the triangle-shaped apparatus), but amplifies it based on the oscillator (fed to the ‘plus’ pin).
As an example, the built in oscillator returns only 5 and 0 volts (5 being the operating voltage of the circuit, 0 being ground). So when the oscillator is set to high (5 volts), then the input source will be amplified to 5 volts. When at 0 volts, the input source is not amplified at all… Here’s a picture demonstrating this:

The top wave is the final output, and the bottom is the ‘carrier’ frequency… That’s all there is to it, really– the rest is just conditioning the circuit so it’ll function without adding any unwanted distortion!

Probably not. Basic context:

When electronic parts are needed for a project, you could either go to Radioshack (convenient but expensive), or order them from online (cheap but slower). For the longest time, Max and I have had a hard time finding the best site to order from- whether it be because of part stock, pricing, shipping time, or otherwise. The main place we kept revolving around was Mouser (www.mouser.com), because they’re located just outside of Ft. Worth, making shipping cheap.

Recently, during the summer, we consulted this guitar repair man in Austin Vintage Guitars. We asked him about a possible suggestion for a good, reliable place to get parts. He told us about this great site called Tayda Electronics (www.taydaelectronics.com)!

This company, however located in Bankok, has the cheapest parts for electronics I’ve ever seen. And, for being in Thailand, it has relatively cheap shipping!

That’s all for today, folks, happy bending/modding/breaking/building!

-Secoyatree

P.S. This site is where I’ll be ordering the parts for the vocoder Max and I will be building!

Arduino Keyboard
This was a project that I really wanted to finish, but was unfortunately postponed due to some… complications. (I’ll get into that later!) The idea was to create a tiny, MIDI compatible keyboard, using keys scrapped from a kid’s toy.

..Not pictured is of course the Arduino chip. The keyboard works in an odd way, due to me wanting to conserve the amount of pins on the chip. Since the Arduino only has 14 digital pins, (meaning working with values of just 0 and 1) it wouldn’t be smart to assign each pin to a single key, as that would leave me very little room to work with. So I decided that I would rather use the analogue pins, which can process data anywhere between 1 and 0. Doing this was possible through a voltage divider set up through resistors:

This would mean that pressing the first key would divide the given 5 volts by 1, pressing the second key would divide it by two, etc. The resulting voltage would be sent to the Arduino as a value from 0 to 1023, and there it would be used to calculate a desired frequency. Each key is actually just a standard switch, which you can see here.

Now I mentioned earlier that I encountered some ‘complications’ in trying to build this on a permanent board. I’m not sure exactly what caused it– I assume it had to do with some bad connection, or perhaps the quality of the components– but every once in a blue moon the keyboard would become completely sporadic and unstable. This means that it would start producing some bizarre sounds, without any way to stop it. Here is a lovely sound clip! (Prepare your eardrums)

Maybe I’ll pick this up again someday, especially since now I’ve found some cheaper places to get parts…

Arduino 16 Step Sequncer
Many of our projects came out of the greatness of the Arduino project. Essentially, the Arduino is a magical little board that combines aspects of circuitry and computer programming. The result is rather amazing- we couldn’t find anything that we couldn’t do with it! Secoya and I decided on making a rudimentary sequencer with the Arduino, which despite being a bit twitchy and resembling an IED, works rather well!

Here’s how it works…
One knob controls the speed at which the melody is played. The other knob is a general ‘control’ knob, and a button switches through the three different modes of the sequencer. ‘Play’ mode will play through the sequenced notes on loop- by default, a chromatic scale is programmed in. The second mode, ‘Select’ mode, allows the user to choose which of the 16 positions to edit. Once selected, ‘Edit’ mode will use the ‘control’ knob to enter the desired note.

The biggest technical accomplishment on it was actually its display- similar to ones you’ve likely seen on digital alarm clocks or kitchen timers. What I did was have each segment on the display (there are eight total segments, despite being called ‘Seven-segment displays’) assigned to a pin on the Arduino. Each desired character to be displayed is represented by a series of 0s and 1s, which are then flashed to the display whenever told to- thus displaying a number or letter!

But enough technobabble for now. Here’s a video of the thing in action…

Yeah, this site is the best.
It takes an input phrase, translates it to a language, back to English, and continues with every language it can get it’s hands on.
Check it out here.

Try things such as:

“Coffee is the elixir of the gods” (Universal)

or

“No wifin’ in the club, give me twenty dollars, give me twenty dollars, give me twenty dollars.”

The video goes into a lot more depth than the first one did, and it’s also properly edited this time around. Hoorah!

The Arduino is a microcontroller board intended to make circuitry/projects a lot easier. For more info- click here, and here

On Adafruit, they have a bunch of useful electronic parts and projects, and recently, I noticed they have these, touch pads that were used in the Nintendo DS! So instead of buying one, I decided to take apart my old (dead) DS and spare it’s touch pad and two screens…

Then, an idea struck- What if were to use an Arduino to produce varying frequencies in different waveforms, and control it with the touch pad, thus having an Arduino KAOSSillator DIY NDS Clone!

So, it was on- I ordered the parts (including an Arduino and touch pad breakout board), and they should be arriving friday…

So until I get these parts and start to work on this project, I bid you a happy thursday morning (I actually should be in bed, it’s ~12:46am…)!

Happy Project Building/killing Modding,

Secoyatree