The 1974 issue 2 of The Audio Amateur marks a milestone in DIY audio, offering professional-grade console designs and a comprehensive look at the quadraphonic revolution. Here are the highlights to entice your inner audio engineer:
- An IC Preamp/Console: Stop settling for "all-in-one" systems and build a professional quality audio console designed to be the collector and distributor for every sound source in your system. This modular powerhouse features 13 separate amplifiers, including dedicated circuits for mixing, monitoring, and even live microphones.
- W(h)ither Quadraphonics?: Get the definitive report on the state of four-channel sound. This deep dive evaluates the competing matrix and discrete CD-4 systems, providing expert analysis on the latest demodulators, cartridges, and specialized styli needed to achieve a true "illusion of reality".
- Regulated & Current Limiting Power Supplies: Eliminate hum and bias shift with a family of sophisticated regulated power supplies. These designs offer versatile outputs from 16 to 68 Volts and include active current limiting to protect your expensive output transistors from accidental shorts.
- IC Op Amps for Audio: Master the technical foundations of modern circuitry with Walt Jung. This installment focuses on critical dynamic characteristics like slew rate and gain bandwidth product, and even includes a schematic for a handy IC tester you can build to verify your components are functional.
- Learning to Use Transistors: Explore the "designer’s dream"—the Field-Effect Transistor (FET). Learn how these devices mimic the desirable characteristics of pentode tubes and how to implement them in common source and follower configurations for high-performance audio applications.
- Audio Aids and Comfort: This issue is packed with practical workshop wisdom, from repairing Teac tape decks to achieving a professional finish on equipment panels and a clever trick for drilling perfectly round holes in sheet metal.
Table of Contents
- An IC Preamp/console: Part one: by Richard Kunc ........................................................... 4
- W(h)ither Quadraphonics?: by B. V. Pisha .......................................................................... 7
- A Family of Regulated & Current Limiting Power Supplies: by Joshua I. Goldberg ... 13
- Audio Aids and Comfort: by readers Resler, Gilmore, and Gloeckler .......................... 16
- IC Op Amps for Audio: by Walt Jung .................................................................................. 18
- Learning to Use Transistors: by C.N.G. Matthews .......................................................... 24
- Letters ........................................................................................................................................ 27
- Advertiser Index ................................................................................................................... 27
- Classified ................................................................................................................................... 29