If ever you want to build your own guitar amplifier, here’s the first thing you need to build. This is because guitar preamp are not usually sold as a kit unlike amplifiers. Guitar preamp are actually simple and usually consist of 2 stage, first – gain stage which amplifies the signal coming from the guitar and second – the filter stage which boost or cut frequencies that is determined by the user. Some preamp also includes effects such as distortion and reverb as the most common.
Simple Solar Charger
Since electricity is one of our basic needs and it doesn’t come for free. In fact it increases every year. Meanwhile sun power is free for all so why not use it? Here is a very simple way to charge your battery using solar power.
Why need a charging circuit?
Solar cells and batteries comes in different voltage and current capacity. You need to match these ratings for safety and reliability reasons. Connecting a higher voltage solar panel to a battery might over charge the battery and may cause it to explode. It is best to limit the voltage and current output of the solar panel to avoid this from happening.
TDA7498 – 200W class D audio amplifier
Many years ago, it is not easy to build a powerful audio amplifier. You will need big power transistors with massive heavy heatsinks plus a heavy transformer too. It will also require a lot of efforts to build it, from drilling the heatsinks and connecting those wires. It is a very tiring task. Today a 200W amplifier can be as small as your mobile phone. Thanks to the evolution of Class D audio amplifiers. Smaller and more efficient amplifiers are now possible.
Electronic Audio switch with crossfade
Often times we used a simple toggle switch to switch between audio source. This is the easiest and simpliest method. But this simple circuit creates some clicking or boom sound when switching audio sources specially when the 2 audio source are operating. Here’s a simple and effective circuit to switch between audio sources gently. It gently decrease the volume of the audio source previously selected and while slowly increasing the volume of the selected audio source.
DIY Loud Bluetooth Speaker for your car
Building a bluetooth speaker nowadays won’t require so much technical knowledge. You just need to know how and where to connect wires. You can now buy a bluetooth receiver with a built in amplifier online and make your own audio system for your car for cheaper price.
WHY DIY(Do it Yourself)?
Some cheap car amplifiers on the market is not honest on their advertised power, these are very common to cheap and not so known brands. By doing it yourself, aside from getting cheaper, you can also be sure that your amplifier has the right power you need.
Simple DI box
Last time I have featured an active Di box circuit. Here is a more simple circuit that only uses 1 JFET instead of an OPAMP.
This circuit is so simple that you can actually build it without PCB. You can also just use a universal board on this one. I actually copied this circuit from an acoustic guitar. haha! sure it works and I also have simulated it.
3W x 2 class D amplifier
In case you wan to build an small amplifier for your small speaker, here’s a 3W per channel amplifier for you. Take note that this can only operate up to 5.5V. You can’t use USB to power this circuit as USB can only provide up to 2.5W power. If you will use 8 ohms speaker, it can only provide up to 1.4W of power.
Minimum value of Ri is 18k. Minimum speaker impedance is 4 ohms.
SIMetrix Basics Tutorial
Simetrix is a very powerful circuit simulation software for electronic circuits design. I use it a lot and is very helpful and most all you can get it for free. The free version has circuit size limitations but still adequate for most hobbyist designs.
Bass Booster Circuit design
If you love listening to a music with super loud bass, then here’s a circuit that can help you boost the bass. There are many ways to boost the bass and I will be sharing some of the most simple ways. And of course the simulation result, if it works on the simulation then it will also work on the actual.
The circuit
The circuit is very simple and only needs few components.
Tone Control Circuits for guitar effects
There are many tone control designs out there. Let’s take a look at those and analyze each circuit. If you are planning on designing a tone control circuit for your guitar effects, it is not actually that not hard to do. You only need to understand the basics. Please note that these are only passive type tone control meaning you will loose some signal strength when you use this circuit. To compensate for the attenuation caused by this circuit, you will need to add an amplifier circuit with a gain of at least 2.