Hobby Electronics, Do it Yourself Projects, Audio, Video, Home Gadgets, DIY.
Danish Audio ConnecT - Denmark
The DACT Attenuation Curve Calculator (ACC) is a tool to assist DACT customers and others 
interested in designing their attenuator / volume control circuit correctly. The ACC is especially useful for calculating passive volume controls (passive preamps).The Attenuation Curve Calculator is a Microsoft Excel spreadsheet (version 5.0 or later). It requires only input of three figures to run a complete set of curves.
Runoffgroove - Audio and Sound Effects
Multi-Face - Inspired by Tim Escobedo's "The Many Faces of Fuzz." Build notes, photo, and PCB/perfboard layouts.
Mr. EQ - A simple, yet potent DIY equalizer. Schematic, PCB/perfboard layouts, and photos.
Little Gem - Two 9v battery-powered amps based on the LM386. Schematic and PCB/perfboard layouts.
Eighteen - The Marshall 18W adapted for use as a distortion stompbox. Schematic, PCB/perfboard layouts, and photos.
Tonemender - An ultra-flexible tonestack with clean boost. Schematic, photo, and PCB/perfboard layouts.
Thor - The legendary Marshall 100W Super Lead adapted for use as a distortion stompbox. Schematic and PCB layout.
Splitter-Blend - Dual parallel buffered effect loops with blend control. Schematic and perfboard/PCB layouts.
Professor Tweed - The Fender Princeton adapted for use as a distortion stompbox. Schematic, PCB/perfboard layouts, and photos.
Electronic Peasant DIY Projects
The Peasant is dedicated to inexpensive, easy, and fun Do-It-Yourself electronics projects, particularly those which involve music production and reproduction as well as alternative energy. 
Jason Neals DIY Audio and Electronics
Dual Polarity Power Supply
Two versions of a dual polarity power supply with printed circuit board artwork. The supplies are built around the popular LM317 & 337 complementary voltage regulators which offer very high ripple rejection as well as short-circuit and thermal protection.
Microphone Preamplifier
A battery-powered microphone preamplifier and microphone wand for acoustic tests and recording. The preamplifier features 20dB of switchable gain and a clipping indicator,
Amplifier.cd - measuring instruments - audio
The Content consists of theory, test, analog technique and measuring instruments for amplifiers, electronics and Hifi. A Tutorial describes fundamental ideas of electro-technology and the general amplifier and audio technology. The test equipment gallery shows measuring instruments - older, historical and partly new.
Elliott Sound Products - The Audio Pages
The above pages has many useful ideas and practical tips.
It is by Hobby and DIY - Do it Yourself, Education Starts even without books. Then you need to read to enhance your abilities to Design your own.
In order to compensate or enhance your education, you need to work at a small shop as an apprentice even as a student, not for the sake of project work alone. An Evening job at a factory or a home mini workshop-lab is very essential for obtaining the skills.
Solderman 1702 - from the delabs Archives
Sam Electronic Circuits
Audio Preamplifier, filter, crossover circuits, Audio Power Amplifier circuits, Automobile - car circuits, Audio Equalizer circuits, Battery circuits, Computer circuits, Clock and Timer circuits, Decoder circuits, Digital circuits, Electronic Switch circuits, Light Effect and Controller circuits, Measurement - Test circuits, Oscillator circuits, Power Supply circuits, Tube Preamplifier circuits, Tube Power Amplifier circuits, Video circuits, Vu Meter circuits.
