Books | Audio & RF

Easy and Affordable Digital Signal Processing The aim of this book is to teach the basic principles of Digital Signal Processing (DSP) and to introduce it from a practical point of view using the bare minimum of mathematics. Only the basic level of discrete-time systems theory is given, sufficient to implement DSP applications in real time. The practical implementations are described in real time using the highly popular ESP32 DevKitC microcontroller development board. With the low cost and extremely popular ESP32 microcontroller, you should be able to design elementary DSP projects with sampling frequencies within the audio range. All programming is done using the popular Arduino IDE in conjunction with the C language compiler. After laying a solid foundation of DSP theory and pertinent discussions on the main DSP software tools on the market, the book presents the following audio-based sound and DSP projects: Using an I²S-based digital microphone to capture audio sound Using an I²S-based class-D audio amplifier and speaker Playing MP3 music stored on an SD card through an I²S-based amplifier and speaker Playing MP3 music files stored in ESP32 flash memory through an I²S-based amplifier and speaker Mono and stereo Internet radio with I²S-based amplifiers and speakers Text-to-speech output with an I²S-based amplifier and speaker Using the volume control in I²S-based amplifier and speaker systems A speaking event counter with an I²S-based amplifier and speaker An adjustable sinewave generator with I²S-based amplifier and speaker Using the Pmod I²S2 24-bit fast ADC/DAC module Digital low-pass and band-pass real-time FIR filter design with external and internal A/D and D/A conversion Digital low-pass and band-pass real-time IIR filter design with external and internal A/D and D/A conversion Fast Fourier Transforms (FFT)

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Vacuum-tube (or valve, depending upon which side of the pond you live on) technology spawned the Age of Electronics early in the 20th Century. Until the advent of solid-state electronics near mid-century, hollow-state devices were the only choice. But following the invention of the transistor (after their process fell to reasonable levels), within a couple of decades, the death of vacuum tubes was widely heralded. Yet here we are some five decades later, and hollow-state equipment is enjoying something of a comeback, especially in the music and high-end audio industries.Many issues surround hollow-state audio: Does it produce—as some claim—better sound? If so, is there science to back up these claims? How do hollow-state circuits work? How do you design hollow-state audio circuits? If hollow-state equipment fails, how do you go about troubleshooting and repairing it? Can we recreate some of the classic hollow-state audio devices for modern listening rooms and recording studios? How can we intelligently modify hollow-state amplifiers to our taste? These and other topics are covered in The State of Hollow State Audio.

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The short-wave technique has a very particular appeal: It can easily bridge long distances. By reflecting short-wave signals off the conductive layers of the ionosphere, they can be received in places beyond the horizon and therefore can reach anywhere on earth. Although technology is striving for ever higher frequencies, and radio is usually listened to on FM, DAB+, satellite or the Internet, modern means of transmission require extensive infrastructure and are extremely vulnerable. In the event of a global power outage, there is nothing more important than the short-wave. Amateur radio is not only a hobby, it’s also an emergency radio system! Elektor’s SDR-Shield (SKU 18515) is a versatile shortwave receiver up to 30 MHz. Using an Arduino and the appropriate software, radio stations, morse signals, SSB stations, and digital signals can be received. In this book, successful author and enthusiastic radio amateur, Burkhard Kainka describes the modern practice of software defined radio using the Elektor SDR Shield. He not only imparts a theoretical background but also explains numerous open source software tools.

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This comprehensive book on audio power amplifier design will appeal to members of the professional audio engineering community as well as the student and enthusiast. Designing Audio Power Amplifiers begins with power amplifier design basics that a novice can understand and moves all the way through to in-depth design techniques for very sophisticated audiophiles and professional audio power amplifiers. This book is the single best source of knowledge for anyone who wishes to design audio power amplifiers. It also provides a detailed introduction to nearly all aspects of analog circuit design, making it an effective educational text. Develop and hone your audio amplifier design skills with in-depth coverage of these and other topics: Basic and advanced audio power amplifier design Low-noise amplifier design Static and dynamic crossover distortion demystified Understanding negative feedback and the controversy surrounding it Advanced NFB compensation techniques, including TPC and TMC Sophisticated DC servo design MOSFET power amplifiers and error correction Audio measurements and instrumentation Overlooked sources of distortion SPICE simulation for audio amplifiers, including a tutorial on LTspice SPICE transistor modeling, including the VDMOS model for power MOSFETs Thermal design and the use of ThermalTrak transistors Four chapters on class D amplifiers, including measurement techniques Professional power amplifiers Switch-mode power supplies (SMPS)

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Learn to use inexpensive and readily available parts to obtain state-of-the-art performance in all the vital parameters of noise, distortion, crosstalk and so on. With ample coverage of preamplifiers and mixers and a new chapter on headphone amplifiers, this practical handbook provides an extensive repertoire of circuits that can be put together to make almost any type of audio system. A resource packed full of valuable information, with virtually every page revealing nuggets of specialized knowledge not found elsewhere. Essential points of theory that bear on practical performance are lucidly and thoroughly explained, with the mathematics kept to a relative minimum. Douglas' background in design for manufacture ensures he keeps a wary eye on the cost of things. Includes a chapter on power-supplies, full of practical ways to keep both the ripple and the cost down, showing how to power everything. Douglas wears his learning lightly, and this book features the engaging prose style familiar to readers of his other books. You will learn why mercury cables are not a good idea, the pitfalls of plating gold on copper, and what quotes from Star Trek have to do with PCB design. Learn how to: make amplifiers with apparently impossibly low noise design discrete circuitry that can handle enormous signals with vanishingly low distortion use humble low-gain transistors to make an amplifier with an input impedance of more than 50 Megohms transform the performance of low-cost-opamps, how to make filters with very low noise and distortion make incredibly accurate volume controls make a huge variety of audio equalisers make magnetic cartridge preamplifiers that have noise so low it is limited by basic physics sum, switch, clip, compress, and route audio signals The second edition is expanded throughout (with added information on new ADCs and DACs, microcontrollers, more coverage of discrete op amp design, and many other topics), and includes a completely new chapter on headphone amplifiers.

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