Guitar Amplifier using Op-Amp

Today I made a simple guitar amp. I based my design around the 741 op amp chip. There are a lot of ways to make a guitar amp but this one is quite easy and involves only a couple of components. First you will need a 741 op amp chip. One resistor with a value of 470Ω and a 470Ω potentiometer/rheostat. You will also need two nine volt batteries, one acting as the positive supply rail and the other acting as the negative supply rail. An op amp needs both supplies because it amplifies signals that involve positive and negative voltage signals. The last three components you will need is a quarter inch guitar jack, a guitar and a guitar chord.

I have attached the schematic for building this circuit so I will just go into the theory of our guitar amplifier. First the 470Ω resistor is used to be compared to the value of our 470Ω rheostat. We set the amplifier as a non-inverting amplifier so when we turn the rheostat the gain of the signal will increase instead of increasing negatively. A signal is generated from the guitar that is very small and must be amplified. The signal is created by a device usually being an inductor in the guitar that takes the sound signals that you strum and converts it to electricity. Once we increase the amplitude of the guitar signal we send it to a speaker. Now we have audible sound from the guitar. Turning the rheostat to the left (< resistance) lowers the gain and makes the audio cleaner while turning the rheostat to the right(> resistance) saturates the signal and creates a cool distortion sound. Have fun building this one!

AM Transmitter Design

Here is a video of me making an AM transmitter.  It doesn't work that great but I will make it better.

Enjoy the Show!

Radio Waves WOWIE!

I have always been fascinated with radio wave signals.  When I first started learning about them I thought it was magic.  How can a certain frequency carry information which can then be decoded?  Well the radio stations we listen to include AM and FM.  AM radio is different from FM in that AM radio sends its information using amplitude modification and FM sends its information using frequency modulation.  

Transmitting amplitude modulation signals involves a carrier signal that contains audible frequencies within its bandwidth.  The carrier signal only acts as a messenger while the frequencies inside that AM bandwidth contain the audible sound.  Transmitting frequency modulation signals is similar in that it has a carrier frequency but the audible sounds are decoded by phase changes in the carrier signal.  So the audible sound of an AM signal is detected by amplitude changes in the frequency while the audible sound of an FM signal is detected by frequency changes of the carrier signal.  

The way a signal travels through air is an amazing concept.  Transmitters somehow manage to pulse out signals that can be detected hundreds of miles away.  How people do this depends on the intensity of power of that transmitter.  Transmitters need a lot of power output so the signal can be detected within a certain radius.  Air is a horrible conductor so the waves transmitting through the air really need to be pushed to be detectable by radios within the area.  That is why power is so crucial and to be more specific: power is the voltage multiplied by the current of that signal.  So that's how radio works, ain't it cool? 

Finished Fish Tank Design!

The last blog post I was in the process of designing a lighting system for my fish. Well I decided to stay up all last night to finish it up and make it look pretty. I believe it was worth it but my body doesn't seem to agree. The coffee keeps me upright and prevents me from smashing my head into my monitor as I type these precious words. I decided it was time to grow up so I took my setup and integrated it into my old fish tank hood that was without lighting. Check out the video of the finished fish tank design.



I have a couple of questions for you. What do you think I could do to improve this setup? Would you change the colors? Are you interested in seeing my design schematic so you could make this or modify it? I love sharing information and collaborating with others to come up with cool designs. It is always good to have another opinion when creating anything. Your collaboration partner can see things you overlooked or add cool ideas into the brainstorm process. Whether you are creating electronics, writing music or painting pictures, it is always beneficial to have a second opinion. Constructive criticism can sometimes feel like a blow but at the same time can be crucial in the design process. So let me know what you think about my project and don't be shy to ask questions or give some feedback.

Electronics Help Forum

Hey guys and nerds hope all is well. I just wanted to share with you a website that has inspired me to become a total nerd. This website/forum is called AllAboutCircuits.com otherwise known as the AAC. Well the AAC has been a great source of help and knowledge in my project making. The people within the forum are extremely helpful and are just as obsessed with electronics as I am. If you have no idea how electronics work and would like to start, the AAC is a great place to take that step into the unknown. Most of the people on the AAC site make projects so it is a great "clubhouse" to hang out and share information. Electronic projects that I have seen on the site have inspired me to come up with similar designs. It is always fun to take another person's general design and put your twist on it. Here is a picture of a robot a fellow AAC user has been designing. The robot detects obstacles using an infrared detector and avoids those obstacles on its own. Pretty neat!

Another great part about the AAC is the book of information they have created to help other users understand how electronic components work. The book is intended to be read sequentially from beginning to end starting with the basics and then moving forward into electro-magnetism and transistors. I personally have gained a lot of insight into how electronics work from reading these pages. I recommend reading the beginning chapter of the book so you can decide for yourself whether or not you might be interested in the subject.

Fish Tank Disco Night!

Hey interwebs ain't it a good ol' day to start a project?  This is the type of day I should be out playing frisbee or playing hopscotch but NOOO I am inside my house squinting at a circuit design.  Well I came up with a little light show for my fish "Serra", short for Serrasalmus which is a type of piranha species.  Anyways I used a 555 timer circuit which creates intervals that the lights should be on and off.   This is followed by a large CAP that makes the LEDs phase in and out.  I grabbed the high lumen LEDs from Radio Shack which cost me three bucks a pop!  These are the types of sacrifices I make for Serra so he/she can have disco parties...sometimes you just gotta splurge. I got a video that shows how I did it.  Take a look!