@@ -75,7 +75,9 @@ Every synthesizer needs an oscillator. An oscillator is a circuit that takes a s
[diagram]
## Wendy: the NOT gate
I strongly recommend that you read Elliot Williams' [Logic Noise blog post](https://hackaday.com/2015/02/04/logic-noise-sweet-sweet-oscillator-sounds/), because it explains the circuit that the Wendy module uses,
I strongly recommend that you read Elliot Williams' [Logic Noise blog post](https://hackaday.com/2015/02/04/logic-noise-sweet-sweet-oscillator-sounds/), because it explains the circuit that the Wendy module uses, and shows you how to build it on a breadboard.
In short, the Wendy has a chip at its heart that contains a set of inverters, also called NOT gates. Inverters, to borrow a metaphor from Nicolas Collins in *Handmade Electronic Music*, are like a friend who disagrees with whatever you say - that person who always has to play devil's advocate. Send a high voltage into the inverter, and it outputs a low voltage. Send in a low voltage, and it outputs a high voltage (for the chip we're using, 'high' means 9V, and 'low' means 0V).
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@@ -85,12 +87,9 @@ Stitch Synth has two oscillators on it:
* One uses a 2.2nF capacitor, and by touching the input and output points of the oscillator, your body becomes the resistor (in general, touching electric circuits isn't advisable, but in this case it's safe - you won't be getting any electric shocks!).
* The second oscillator uses a 10μF capacitor.
* The second oscillator uses a 10μF capacitor. This value of capacitor creates audio piches when a ...
[diagram]
mixing
## Delia: the phase-locked loop
The Delia oscillator uses a chip that's a little more complex than the Wendy. Again I'm going to send you to [Logic Noise](https://hackaday.com/2015/08/07/logic-noise-4046-voltage-controlled-oscillator-part-one/) to properly understand how it works, as Elliot Williams has already done a great job of explaining this.
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@@ -101,9 +100,10 @@ The Delia module's circuit is exactly the same as the one Logic Noise shows you
Four of the modules allow you to play Stitch Synth by touching them. Here's how they work.
@@ -113,11 +113,14 @@ The Maryam module works with the Wendy module
The design of the Maryam module is a Hilbert curve. Read more in my project diary (link) about this
## Daphne
The Daphne module is one of the modules you can use with the Wendy module. The strips of conductive material on the front and back of Daphne create one long path of conductive fabric between the two metal snaps. Pulling on the fabric tabs shortens this path, which lowers the resistance between the two sides, and raises the pitch you create.
The Daphne module is one of the modules you can use with the Wendy module. The strips of conductive material on the front and back of Daphne create one long path of conductive fabric between the two metal snaps. Pulling on the fabric tabs shortens this path, which lowers the resistance between the two sides, and raises the pitch you create.
The volume module is a fabric version of a potentiometer, working as a voltage divider, but instead of having a continuous range, it has three settings - low, medium and high.
The Hedy module is a simple filter. It's the first step of [this Logic Noise tutorial](https://hackaday.com/2015/03/25/logic-noise-filters-and-drums/) which eventually turns the raw square wave sound of our oscillators into electronic drum sounds! But the Hedy module is simpler than that - using a capacitor, a resistor, and another IC chip, it is a lowpass filter, knocking out some of the higher frequencies of the signal and resulting in a smoother sound.
The Power module is very simple, but very important! It houses the battery that powers the entire synth. Each module has a power, ground, and signal line, and connecting the power module in between the output of one module and the input of another (not Ada, Anni, Daphne or Maryam, but any of the others) will power everything.
