#diyelectronics

[adafruit]

PCB of the day! Metro ESP32-S3 🔧🔋💡

[teardownit]

DIY Dumble-like sounding MOSFET Overdrive

The Hermida Zendrive guitar pedal we will study, assemble and listen to today is a true masterpiece. Many say its sound is close to the Holy Grail of guitar amplification - Dumble Overdrive Special.

Other people are more pessimistic in their judgments. Still, the precise response to the picking dynamics, the Voicing tuning options, and the sheer beauty of this overdrive's sound are simply impossible not to love.

But before we study the Lovepedal Zendrive or its copy of the Landtone Phoenix song, or the Aion effects Azimuth dynamic overdrive, we'll study the evolution of the MOSFET overdrives that finally resulted in the development of this gem.

Fulltone OCD

Mike Fuller was one of the first to start using MOSFETs instead of diodes to limit the amplified guitar signal in 2004.

His Obsessive-Compulsive Drive overdrive-distortion pedal is built on a standard circuit with one dual op amp. The first operational amplifier, X1, amplifies the amplitude of the guitar signal by a factor from 8 to 463 times, depending on the position of the drive control X3. This is a 1-megohm potentiometer.

Further, through resistor R9, the signal is fed to the limiter, which comprises 2N7000 MOSFETs M1 and M2 connected in parallel. A germanium diode D1 - 1N34A is additionally included in series with M2, which makes the limiter asymmetrical and, therefore, makes more interesting sound.

A limiter in overdrives is usually included in the negative feedback circuit of an operational amplifier (i.e., in parallel with C6). Such a limiter is called a soft limiter.

And here, a hard limitation is applied: clipping sections are included between the preamplifier output of the gain section and the virtual ground - half of the supply voltage Vref, formed by resistors R4 and R7.

Virtual ground is used in the unipolar powering of operational amplifiers to amplify analog signals, such as audio signals. The guitar signal does not change from zero to plus but from minus to plus, passing through zero.

To prevent the signal from being limited to the circuit's ground, it is shifted in the plus direction by half the supply voltage.

Such hard limiting is typical for distortion pedals. But by using MOSFETs instead of diodes or LEDs, the top of the signal is not cut hard but softly rounded. Therefore, OCD can work as both distortion and overdrive.

Due to the smoothed peaks of the limited signal, the sound is highly dependent on the sound's attack dynamics. For rock and especially blues, this is very valuable. With modern metal pickups that compress the dynamic range of the signal, it can help make solos sounding more sweet.

The second operational amplifier X3 amplifies the limited signal by a factor of 3.8, correcting its timbre. Capacitors C6 and C9 prevent the self-excitation of operational amplifiers at high frequencies.

Next is a simple passive tone knob, which implies a treble leak circuit. Potentiometer X4 10 kilohms and capacitor C11 47 nanofarads are connected in the same way as on the pickguard of any electric guitar.

The Switch1 switch changes the circuit's output impedance as if the high-impedance and low-impedance pickups were switched. When it's open, you get a transparent overdrive like the Klon Centaur, and when it's closed, you can get a more aggressive sound like the Marshall Plexi.

Hermida Audio Zendrive

The Zendrive pedal's authors, Hermida audio technology (now produced by LOVEPEDAL LLC), have undoubtedly studied the Fulltone OCD thoroughly. Let's find the differences between the two circuits.

First, the limiter is included in the operational amplifier feedback, that is, between the output and the inverting input, not between the output and virtual ground. That is, here we have a soft limiter.

Secondly, one diode is added in series with each MOSFET. Clipping remains asymmetric: we have one diode in the left arm of the limiter and two diodes in the right arm.

Third, the second operational amplifier is used as a voltage repeater, aka buffer: the output is directly connected to the inverting input.

Fourth, the tone control is implemented a little differently: two OCD`s switchable resistors are replaced by a potentiometer.

And finally, the most critical, fifth difference. A potentiometer is included in the tone correction circuit between the inverting input of the first operational amplifier and the artificial midpoint.

This fourth knob, Voicing, or Character, allows you to smoothly adjust the lower frequencies in the overdrive structure over a wide range, similar to the Resonance control on many tube guitar amps.

The potentiometer is signed as a trimmer in the diagram because some pedal makers don't want to install a fourth knob on the pedal`s body. This is what Landtone did when developing the Phoenix Song Overdrive DIY kit.

The developer suggests installing the trimmer on the PCB, and to access it, you need to disassemble the pedal by unscrewing the footswitch nut and taking out the PCB.

But I will not be lazy to drill an extra hole in the pedal body and install a potentiometer with a knob, connected to PCB by wires instead of the trimmer. Because I consider this regulator simply invaluable and irreplaceable.

Before we get to assembly and testing, let's look at another pedal with a similar adjustment. However, it is based not on the Fulltone OCD but on the Ibanez Tube Screamer.

The Precision Drive

This is a signature pedal by Misha Mansour of Periphery, manufactured by Horizon Devices. Compared to the original Overdrive Pro TS808, the circuit adds a noise suppressor, which we will not consider, and an exciting ATTACK switch.

The Precision Drive scheme was studied and partially replicated by PedalPCB and PCB Guitar Mania. They are manufacturers of DIY kits for guitarists. Their products are called Dwarven Hammer and Collision Drive, respectively. A noise gate is not provided there, but the attack switch is implemented. This is the main difference between Precision Drive and many other overdrive pedals.

In the Fulltone OCD schematic, we saw a resistor switch at the tone shaping circuit in the output section. The Zendrive has a variable resistor in the preamp's RC circuit which is controlling the overdrive structure.

Precision Drive has a constant resistor in the same place, between the inverting input of the overdrive section operational amplifier and the virtual ground, but the capacitors are switched.

This is the same thing: we change the time constant of the RC circuit, which adjusts the audio signal's frequency spectrum. At the same time as the time constant, the complex impedance changes, thus the gain.

A resistor is a resistance to both DC and AC current. At the same time, a capacitor is only resistant to AC current because DC current does not flow through a capacitor. Since DC current does not flow through our RC circuit, there is no difference between adjusting the resistance and switching the capacitance.

But the active/reactive ratio affects the circuit's Quality factor, i.e., its resonance. It's no coincidence that the knob on guitar amplifiers, which adjusts the same frequencies as our potentiometer or switch, is often called RESONANCE. And it is used to adjust to the resonance of the electromechanical system - the loudspeakers in the cabinet, along with the masses of air in and around it.

The reactive impedance accumulates energy and gives it away, except for losses due to dielectric recharging and magnetizing the magnetic core in inductors. This is why coreless inductors are often used in high-end equipment, so-called air inductors. They weigh a lot, take up a lot of space, and are expensive because copper is more expensive than steel. But these are the laws of physics on which technology is based.

Unlike reactive impedance, active resistance converts electrical energy into heat, thus reducing the Q-factor. In some cases, it is necessary and useful. In others, it is harmful. Or it simply creates a unique sound character.

That's why switching capacitors and turning the potentiometer knob in the feedback circuit of an audio frequency amplifier is almost the same thing, but not quite. And it's great that there are such different variants of guitar overdrive pedals!

Landtone Phoenix Song Overdrive

Now you can hear how my Zendrive from the Landtone OD-1 kit sounds, with a Seymour-Duncan SH4 humbucker on a Gibson MM Explorer guitar, into an Orange MT20 with a Torpedo Captor X. And see how I assembled the pedal and also a kitten walking around the table and prancing around.

I liked the pedal, especially its fourth magic Voicing knob, which does things to the sound that other tone controls can't. I also liked the bird on the body. Because I love birds. And in the music world, the decoration of instruments and hardware plays no small role because it inspires creativity. And the fact that the pedal is assembled by my hands also warms my soul and creates inspiration.

[its-not-gay-to-be-gay]

The idea is for people who live with someone, and this someone does not know how to knock on the toilet door to check if it is occupied!!!

This is a simple device based on some kind of microcontroller that turns on the red backlight along the contour of the door if the latch is closed, and turns on the green backlight when the latch is open. The latch in this case works as a switch, and the microcontroller checks whether there is power on the pin connected to the latch and thus knows which backlight to turn on.

As a result, we get a demonically red illuminated door that hates this someone who does not know how to knock on this very door!

Even If I dont make it myself, I'll post everything you need for this project.

[d0nutzgg]

Raspberry Pi Projects

Raspberry Pi is a tiny computer that packs a punch! It's a single board computer that's small enough to fit in the palm of your hand, but powerful enough to run a variety of projects. Whether you're a beginner or a seasoned pro, there's a Raspberry Pi project for you.

One of the most popular projects for Raspberry Pi is creating your own media center. With software like Kodi, you can turn your Raspberry Pi into a streaming device that can play all of your favorite movies and TV shows. You can even add a touch screen and use it as a portable media center.

Another popular project is creating a retro gaming console. With software like RetroPie, you can emulate all of your favorite classic games and play them on your Raspberry Pi. You can even connect it to a TV or monitor and use it as a standalone gaming console.

Raspberry Pi can also be used for home automation projects. You can use it to control lights, thermostats, and other smart devices in your home. You can even use it to set up a security system or create a smart mirror.

Raspberry Pi is also great for learning to code. You can use it to learn programming languages like Python and Scratch. There are also a variety of educational resources available that can help you learn how to code and build projects with Raspberry Pi.

Overall, Raspberry Pi is a versatile and affordable computer that can be used for a wide range of projects. Whether you're into gaming, home automation, or coding, there's a Raspberry Pi project that's perfect for you. So why not give it a try and see what you can create!

[mikrozone]

LibrePCB 0.1.7 - Measurement tool + Snap points

[amrartrprojects]

Live at Π6, Athens, July 2022

Spoken Word by Yannis Mihos and electronics.

Group Improvisation

[cyrusmehdipour]

DIY Digital Laser Ruler Tutorial with VL53L0X GY-53, SSD1306, and Wemos ...

[linhkientop]

Mạch điều tốc dimmer 10A DC từ 9V đến 50V chuyên dùng gắn cho mottor điện

[alinagentry90]

How To Make Electronics Water Diya At Home

Creating a water diya at home is a simple and fun electronics project that anyone can try. Here's a step-by-step guide to make your own water diya:

Gather the materials: You'll need a small plastic or glass container, two metal electrodes (like copper or aluminum rods), a battery, and some water.

Prepare the electrodes: Clean the metal rods to ensure they conduct electricity well. You can use sandpaper or a metal cleaner for this.

Fill the container with water: Pour water into the container until it's about three-quarters full.

Insert the electrodes: Place one electrode on each side of the container, ensuring they don't touch each other.

Connect the battery: Attach the positive terminal of the battery to one electrode and the negative terminal to the other.

Test it out: Once everything is set up, the circuit should be complete, and you should see a small current passing through the water, creating a gentle glow.

Adjust as needed: If the diya doesn't light up, check the connections and make sure everything is securely in place.

Learn More - https://goglobalways.com/blog/how-to-make-electronics-water-diya-at-home/

[adafruit]

Bringing up the Python Camera S3 - PREVIEW ! Espressif ESP32-S3, an open-source digital camera 📸🔧🐍

[electronics-components]

Devlopment board

[learnandgrowcommunity]

Practical Exercise 01 | Step-by-Step: Designing a Half Adder with Xilinx Vivado | VHDL | In Hindi

In this practical exercise, you will be guided through the process of designing a half adder using Xilinx Vivado and VHDL. The step-by-step instructions will ensure that you understand each stage of the design process thoroughly.

Subscribe to "Learn And Grow Community" Follow #learnandgrowcommunity

[electronicconference]

World Electronic Materials Conference December 16-18, 2024 | Singapore

More information: electronicmaterialsconference.com

For Enquiry: contact@electronicmaterialsconference.com

[dushume]

I was delighted to be invited to give an artist talk about my practice and also perform at the Quorum based in the ArtsOne Building's Pinter Studio at Queen Mary University in Mile End, London. Quorum is affiliated with the School of English and Drama.

Thank you to Henry, Heath and all the Quorum Committee, and big thanks to David Wright for the technical support on lighting and sound, plus Zoom!

[livewirehopecollege]

Unlock the power of embedded systems with us! 🚀 Dive into a world of innovation and technology where every circuit, code, and connection matters. Read more: https://livewirecoimbatore.com/

Reach Us: 8870275880

Embedded Systems