Channel: DIY Experiments

Category: Science & Technology

Description: • Link of our Facebook page : facebook.com/DIY.Experiments.YouTube • Text of the video : Hi everyone, in this video, we’re gonna show you how to transform an acustic guitar into an electric one. In addition, you could just like us, use only waste-materials. Right now, we’re gonna try our folk guitar with its homemade electromagnetic sensor. After that, we’re going to explain how it works, and also, how to build the sensor. In order to make our guitar compatible with any e guitar amplifier, we’ve added a jack plug to our system. First, we’re gonna amplify the guitar’s sound without any other effect. This is a little comparison of the sound: Without amplifier ! Now, with amplifier. Playing with a louder volume is nice, but it doesn’t add much to the guitar tone. Now, we’re gonna use the amplifier in a way to make an electric guitar’s sound. One of the main effects of the electric guitar is saturation. We make the gain much higher than volume. It’s coul to create your own e guitar, but there is little chance that you already pozess an amplifier! That’s not a problem, if you have a Hi-fi, it will diou. To get saturation, you can create your own preamplifier with an ampli op. You can also build your own amplifier, but it’s a bit more difficult. All connections are made. A little test without hi-fi! And now with it! The other advantage of this system is that we can record in a very good quality. Using a cable inserted into the line input jack, we can connect the electromagnetic sensor and the computer. After starting the computer software Audacity, we put Mic Volume to the maximum, and we choose line input and a single input channel. Recording is started and we notice that the voice causes no interfErence. This way, one could compose its own music. After some adjustments, it could give a great result. As you already understood, to transform an acoustic guitar into an electric one, an electromagnetic sensor should be made. The sensor works only with metal strings. So let’s forget about those in nylon. In theory, the electromagnetic sensor’s functioning is easy, but we did face a lot of problem to make it. The goal is to create an electric current from the string movement. An electric current can be created in a coil of wire from a magnetic field variation, for example: in a generator, an electric current is created if we move coils in front of magnets. But the problem is that strings aren’t magnets. So we can’t just put a coil in front of them to get the signal. We have to make the strings slightly magnetic, by using magnets that aren’t attached directly to the strings. We’ll use remote magnetisim by placing them on the sensor. A little test: If a non-magnetic ring and a magnet ar’ brought closer without touching, the ring become temporarily magnetic, until I remove my hand. Therefore, our sensor contains magnets, which are facing on the same polarity. These magnets transform the thin metallic rods into magnets, that in turn magnetize the strings. The rods are thin enough to allow winding a thousand coil turn, and also to bring them out to the other side. To build the sensor, you’ll need: magnets, a transformer, a wooden plank, molly screws and a butterfly nut. For the magnets, we used the one’s we find in little speakers. They’ve gotta be facing the same polarity, but be careful, in this position, the magnets repel, so you’ve got to force them to hold. After that, you have to recover the primary winding of the transformer. But, it’s a delicate task because you have to remove the steel plates, one after the other. Regarding the wood, to be secure we recommend solid wood. In order to keep homogeneity, the one we’ve used has the same color as the head of our guitar. Now, to make the magnets hold easily, the molly screws were cut. But it still needs cyanoacrylate glue to make sure it’ll hold very well. Then, you have to drill holes in wood, add the coil, and at last add the attachment system. Finally, a wire and a jack plug could be added, shape its wooden support to make it homogenus with the guitar. You don’t have to drill any hole in the guitar, A little experiment to illustrate the Larsen effect: I’ll scratch the 110 Hertz string near the hi-fi speaker, and see what happens. We notice that the sound is increasingly louder, and that the string vibrates indefinitely. Unlike what one might think, it’s not the electromagnetic sensor that causes the string vibrations. When the rope moves, the sensor generates an electrical signal representative of the vibrations of the string. The signal is amplified and the speaker diaphragm vibrates the same way. The sound has exactly the same tone as that of the string. Due to the resonance, it vibrates with sound energy. Then, the phenomenon intensifies until reaching the amplifier’s limit. Bonus: the electric guitar version of Bach’s suite.