A Toolbox for Audio Lovers and Engineers
Without any ambition to reach scientific levels, this book aims to be a toolbox for both audio lovers and high-end equipment designers. The elementary theory presented is the bare minimum for readers to grasp the operation and practical use of electrical, electromagnetic, physics, and electronic operations available in the designers’ toolbox. Each tool is explained in a minimum of words and theory without needless coverage of underlying equations or figures.
The book chapters guide you through the process of designing quality amplifiers with vacuum tubes, from the very beginning, considering both technical and subjective requirements – in theory and practice.
The book is a compilation of the author’s notes used in his professional and educational career but was nevertheless primarily written as a result of true love for the audiophile hobby.
Nobody has any doubt that valve amplifiers produce a remarkably beautiful sound. They have a lively, deep, clear, and expressive sound, and dynamically they do not appear to have any limitations. The author investigates, in a systematic theoretical approach, the reasons for these beautiful properties. He develops new models for power valves and transformers, thus enabling the designer to determine the properties of the amplifier during the design process. Mathematical models for the coupling of power valve(s) and output transformer are provided. These will generate new insights in a special kind of distortion: the dynamic damping factor distortion (DDFD). With mathematical models in the complex domain, especially the properties at the limits of our hearing range (from 20 Hz to 20 kHz) are investigated and the minimal stability criteria for the amplifier are formulated. The often-applied negative feedback in amplifiers is extensively modelled and discussed in relation to our hearing appreciating. And after all this theory a fine selection of special amplifiers is presented and discussed.
You will notice in this book that the author not only writes about amplifier technique, but tells about the way the development of valve amplifiers can have an influence on your daily life; even the usefulness of patents is discussed. Summarizing: new theories and solutions for perfect audio with valve amplifiers. Not only the professional and the DIY-er but everyone who wants to understand valve amplifiers will read this book with much pleasure.
A Toolbox for Audio Lovers and Engineers
Without any ambition to reach scientific levels, this book aims to be a toolbox for both audio lovers and high-end equipment designers. The elementary theory presented is the bare minimum for readers to grasp the operation and practical use of electrical, electromagnetic, physics, and electronic operations available in the designers’ toolbox. Each tool is explained in a minimum of words and theory without needless coverage of underlying equations or figures.
The book chapters guide you through the process of designing quality amplifiers with vacuum tubes, from the very beginning, considering both technical and subjective requirements – in theory and practice.
The book is a compilation of the author’s notes used in his professional and educational career but was nevertheless primarily written as a result of true love for the audiophile hobby.
Valve Amplifiers are regarded by many to be the ne plus ultra when it comes to processing audio signals. The combination of classical technology and modern components has resulted in a revival of the valve amplifier. The use of toraidal-core output transformers, developed by the author over the past 15 years, has contributed to this revival. The most remarkable features of these transformers are their extremely wide frequency ranges and their very low levels of linear and nonlinear distortion.
This book explains the whys and wherefores of toroidal output transformers at various technical levels, starting with elementary concepts and culminating in complete mathematical descriptions. In all of this, the interactions of the output valves, transformer and loudspeaker form the central theme.
Next come the practical aspects. The schematic diagram of a valve amplifier often appears to be very simple at first glance, but anyone who has built a modern valve amplifier knows that a lot of critical details are hidden behind this apparent simplicity. These are discussed extensively, in connection with designs for amplifiers with output powers ranging from 10 to 100 watts. Finally, the author gives some attention to a number of special valve amplifiers, and to the theory and practice of negative feedback.
In summary, this book offers innovative solutions for achieving perfect audio quality. Do-it-yourself builders, as well as persons who want to gain a deeper technical understanding of the complex world of audio transformers, valve amplifiers and audio signal processing, will find this book a rich and useful source of information.
Learn KiCad with Peter Dalmaris
The Academy Pro Box "Design PCBs like a Pro" offers a complete, structured training programme in PCB design, combining online learning with practical application. Based on Peter Dalmaris’ KiCad course, the 15-week programme integrates video lessons, printed materials (2 books), and hands-on projects to ensure participants not only understand the theory but also develop the skills to apply it in practice.
Unlike standard courses, the Academy Pro Box provides a guided learning path with weekly milestones and physical components to design, test, and produce working PCBs. This approach supports a deeper learning experience and better knowledge retention.
The box is ideal for engineers, students, and professionals who want to develop practical PCB design expertise using open-source tools. With the added option to have their final project manufactured, participants complete the programme with real results – ready for use, testing, or further development.
Learn by doing
Build skills. Design real boards. Generate Gerbers. Place your first order. This isn’t just a course – it’s a complete project journey from idea to product.
You’ll walk away with:
Working knowledge of KiCad’s tools
Confidence designing your own PCBs
A fully manufacturable circuit board – made by you
What's inside the Box (Course)?
Both volumes of "KiCad Like a Pro" (valued at €105)
Vol 1: Fundamentals and Projects
Vol 2: Advanced Projects and Recipes
Coupon code to join the bestselling KiCad 9 online course by Peter Dalmaris on Udemy, featuring 20+ hours of video training. You'll complete three full design projects:
Breadboard Power Supply
Tiny Solar Power Supply
Datalogger with EEPROM and Clock
Voucher from Eurocircuits for the production of PCBs (worth €85 excl. VAT)
Learning Material (of this Box/Course)
15-Week Learning Program
▶ Click here to open
Week 1: Setup, Fundamentals, and First Steps in PCB Design
Week 2: Starting Your First PCB Project – Schematic Capture
Week 3: PCB Layout – From Netlist to Board Design
Week 4: Design Principles, Libraries, and Workflow
Week 5: Your First Real-World PCB Project
Week 6: Custom Libraries – Symbols, Footprints, and Workflow
Week 7: Advanced Tools – Net Classes, Rules, Zones, Routing
Week 8: Manufacturing Files, BOMs, and PCB Ordering
Week 9: Advanced Finishing Techniques – Graphics, Refinement, and Production Quality
Week 10: Tiny Solar Power Supply – From Schematic to Layout
Week 11: Tiny Solar Power Supply – PCB Layout and Production Prep
Week 12: ESP32 Clone Project – Schematic Design and Layout Prep
Week 13: ESP32 Clone – PCB Layout and Manufacturing Prep
Week 14: Final Improvements and Advanced Features
Week 15: Productivity Tools, Simulation, and Automation
KiCad Course with 18 Lessons on Udemy (by Peter Dalmaris)
▶ Click here to open
Introduction
Getting started with PCB design
Getting started with KiCad
Project: A hands-on tour of KiCad (Schematic Design)
Project: A hands-on tour of KiCad (Layout)
Design principles and PCB terms
Design workflow and considerations
Fundamental KiCad how-to: Symbols and Eeschema
Fundamental KiCad how-to: Footprints and Pcbnew
Project: Design a simple breadboard power supply PCB
Project: Tiny Solar Power Supply
Project: MCU datalogger with build-in 512K EEPROM and clock
Recipes
KiCad 9 new features and improvements
Legacy (from previous versions of KiCad)
KiCad 7 update (Legacy)
(Legacy) Gettings started with KiCad
Bonus lecture
About the Author
Dr. Peter Dalmaris, PhD is an educator, an electrical engineer and Maker. Creator of online video courses on DIY electronics and author of several technical books. As a Chief Tech Explorer since 2013 at Tech Explorations, the company he founded in Sydney, Australia, Peter's mission is to explore technology and help educate the world.
What is Elektor Academy Pro?
Elektor Academy Pro delivers specialized learning solutions designed for professionals, engineering teams, and technical experts in the electronics and embedded systems industry. It enables individuals and organizations to expand their practical knowledge, enhance their skills, and stay ahead of the curve through high-quality resources and hands-on training tools.
From real-world projects and expert-led courses to in-depth technical insights, Elektor empowers engineers to tackle today’s electronics and embedded systems challenges. Our educational offerings include Academy Books, Pro Boxes, Webinars, Conferences, and industry-focused B2B magazines – all created with professional development in mind.
Whether you're an engineer, R&D specialist, or technical decision-maker, Elektor Academy Pro bridges the gap between theory and practice, helping you master emerging technologies and drive innovation within your organization.
From SRPP and Mu-Follower to OTL Designs
Tube amplifiers suffer from distortion. Fortunately, circuits such as the SRPP amplifier, mu-follower, and beta-follower produce minimal distortion even at output voltages of 50 to 100 Vpeak.
These designs are often published with errors. Without a sound understanding of the theory, it is easy to arrive at a flawed design.
In the first section of this book, we investigate the origin of distortion, while in the second we investigate the design of and SRPP and a mu-follower.
On the internet we can find the most exotic designs. Evaluating them teaches us that these designs often make matters worse rather than better. In the chapter on incorrect SRPPs and mu-followers, we sometimes see bizarre and misguided designs where using a simple single-triode amplifier would perform much better.
Push-pull output stages also exist. A great number of them are examined, and their similarity to the SRPP is discussed. This is done especially with the help of the theory behind the OTL based on the ‘mother’ of all OTLs, the Philips HF303.
Finally, attention is given to frequency characteristics and technical matters such as the supply voltage and the filament power supply.
To illustrate these points, there are a few designs covering the subjects discussed.
This book presents much new theory that has not been published before. It is often an eye-opener, showing that many things have a beautiful and unexpected simplicity.
This adjustable circuit board holder is ideal for clamping PCB for soldering, desoldering or rework.
Features
2 adjustable grips on a retractable stand to accommodate various board sizes.
The adjustable clamps allow the PCB to rotate 360 degrees and stay set in any position.
The base of this rigid metal stand features four rubber feet to ensure stability.
Specifications
Product size
30 x 16.5 x 12.5 cm
Max. holding size
20 x 14 cm
Weight
450 g
From SRPP and Mu-Follower to OTL Designs
Tube amplifiers suffer from distortion. Fortunately, circuits such as the SRPP amplifier, mu-follower, and beta-follower produce minimal distortion even at output voltages of 50 to 100 Vpeak.
These designs are often published with errors. Without a sound understanding of the theory, it is easy to arrive at a flawed design.
In the first section of this book, we investigate the origin of distortion, while in the second we investigate the design of and SRPP and a mu-follower.
On the internet we can find the most exotic designs. Evaluating them teaches us that these designs often make matters worse rather than better. In the chapter on incorrect SRPPs and mu-followers, we sometimes see bizarre and misguided designs where using a simple single-triode amplifier would perform much better.
Push-pull output stages also exist. A great number of them are examined, and their similarity to the SRPP is discussed. This is done especially with the help of the theory behind the OTL based on the ‘mother’ of all OTLs, the Philips HF303.
Finally, attention is given to frequency characteristics and technical matters such as the supply voltage and the filament power supply.
To illustrate these points, there are a few designs covering the subjects discussed.
This book presents much new theory that has not been published before. It is often an eye-opener, showing that many things have a beautiful and unexpected simplicity.
Menno van der Veen is well known for his research publications on tube amplifiers used in audio systems.
In this book he describes one of his research projects which focuses on the question of whether full compensation for distortion in tubes and output transformers is possible.
In the past, a variety of techniques have been developed. One of them has largely been forgotten: trans-conductance, which means converting current into voltage or voltage into current. Menno van der Veen has breathed new life into this technique with his research project titled “Trans”. This book discusses all aspects of this method and discusses its pitfalls. These pitfalls are addressed one by one. The end result is a set of stringent requirements for Trans amplifiers.
Armed with these requirements, Menno then develops new Trans amplifiers, starting with Transie 1 and Transie 2. These DC-coupled, single-ended tube amplifiers have unusually good characteristics and are suitable for hobbyist construction. Next the Trans principle is applied to amplifiers with higher output power.
A trial-and-error process ultimately leads to the Vanderveen Trans 30 amplifier, which optimizes the features of Trans. The characteristics of this amplifier are so special and unique that Menno believes he has struck gold. To ensure that variations in tube characteristics cannot interfere with optimal Trans behavior, Menno makes use of simulations and comparison with other amplifier types. This book reads like an adventure story, but it is much more – it is an account of solid research into new ways to achieve optimal audio reproduction.
This book focuses more on practical aspects than on theory, and it has an contemplative nature, as though the author were viewing amplifiers from above. Knowledge elements are integrated and placed in the context of a broad overview.
Even now tube amplifiers still sound great perhaps better than ever before. In part that is because we now have access to modern components such as toroidal output transformers, extremely high-quality resistors and capacitors, and many sorts of wire with good acoustic properties. Modern audio sources, such as CD players, and the latest top-end loudspeakers also enable us to appreciate how well tube amplifiers reproduce music even better than before.
This new book from Menno van der Veen looks at tube amplifiers from more than just a theoretical perspective. It focuses primarily on the design phase, where decisions must be taken with regard to the purpose and requirements of the amplifier, and it addresses the following questions: How do these aspects relate to subjective and objective criteria? Which circuits sound the best, and why? If you want to develop and market an amplifier, what problems should you expect? What are the significance and meaning of measurements? Are they still meaningful, or have they lost their relevance?
Thanks to the enormous processing power of computers, we can now measure more details than ever before. How can these new methods be applied to tube amplifiers? Previously it was sufficient to measure the frequency range, power and distortion of an amplifier in order to characterize the amplifier. Are these measurements still sufficient, or should we start measuring according to how we hear, using real music signals instead of waveforms from signal generators? The author sketches a future where amplifier measurements that conform to our sense of hearing enable us to arrive at new insights.
This book focuses more on practical aspects than on theory, and it has an contemplative nature, as though the author were viewing amplifiers from above. Knowledge elements are integrated and placed in the context of a broad overview.
,
by Clemens Valens
FNIRSI DPOX180H 2-in-1 Digital Phosphor Oscilloscope (Review)
Oscilloscopes sure have made a lot of progress over the past two decades. Twenty years ago, I still used my single-beam analog 20 MHz CRT oscilloscope...
