Audio Amateur 4/1977 PDF

Audio Amateur 4/1977 PDF - Issue is in black & white
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The 1977 issue 4 of The Audio Amateur concludes the year with a powerful mix of vintage restoration, precision testing, and groundbreaking research into what makes audio truly sound "good." Here are the highlights to entice your inner audio engineer:

• Audio Research Remakes the Dynaco Stereo 70: Witness the transformation of a classic. William Z. Johnson of Audio Research takes the venerable Dyna ST-70 and reimagines it with a sophisticated, highly regulated circuit design. This article provides the complete technical details to turn a budget legend into a "state-of-the-art" contender,,.
• Slewing Induced Distortion (SID): The Listening Tests: In the definitive conclusion to his landmark series, Walt Jung puts his measurements to the "acid test." Through rigorous subjective listening evaluations, learn exactly how different levels of SID manifest as audible grit or a loss of "sweetness" in your music,.
• 111dB’s Around the Workshop: Precision is key to a great build. Frederick Gloeckler details how to construct a Constant Resistance Decade Attenuator (CRDA). This professional-grade tool allows you to measure gain and frequency response with a resolution of 0.1dB, far surpassing standard amateur gear,.
• The Super Buff: Mating Hostile Impedances: Stop your tape recorder from "sucking the life" out of your preamp. Walter Morrey introduces a high-performance buffer circuit designed to isolate your signal path from the loading effects of recording equipment, preserving high-frequency clarity.
• The Gately Micromixer: Part 2: Continue your journey into professional-grade recording. This second installment provides the full-size guides and wiring diagrams for the stereo output module of the 16-in, 2-out modular mixing console,.
• Editorial: The Decline and Fall of FM: A veteran engineer provides a sobering look at how commercial interests and signal processing "gimmicks" have degraded the once-pristine medium of FM broadcasting. Learn why the "good stuff" is getting harder to find on the airwaves,.
• Kit Report: Heath’s IM 5248 IM Analyzer: Get the expert verdict on Heath's latest intermodulation distortion analyzer. This report evaluates whether this $170 kit can provide the laboratory-grade accuracy needed for serious equipment design and troubleshooting,.
• Audio Aids: This issue is packed with clever reader hacks, including a DIY tape deck switching circuit, instructions for adding 78 RPM capability to Technics turntables, and tips for improving capacitor fidelity,.
• Classic Circuitry: The Audio Research D-76A: Study the engineering of a modern masterpiece. This issue features the full, detailed schematic for the legendary D-76A amplifier, offering a fascinating look at professional-grade tube design.

Table of Contents

• Editorial: The Decline and Fall of FM by Roy H. Trumbull ..................................................... 3
• Audio Research Remakes Dynaco's Stereo 70: by Edward T. Dell, Jr. ............................... 4
• 111dB’s Around the workshop: by Frederick M. Gloeckler, Jr. .......................................... 12
• The Super Buff: mating hostile impedances: by Walter Morrey ..................................... 18
• Slewing induced distortion in audio amplifiers Part IV: listening tests at last: by Walter G. Jung ........................................................................................................................ 22
• The Gately Micromixer: Part 2: by Edward J. Gately ......................................................... 30
• Kit Report: Heath's IM 5248 Intermodulation Distortion Analyzer: by Frederick M. Gloeckler, Jr. .......................................................................................................... 38
• Audio Aids: by readers Carlstrom, Shults, Sellman, Marsh and Merrick .......................... 44
• LETTERS ..................................................................................................................................... 51
• CLASSIFIED ................................................................................................................................ 57
• CORRECTIONS .......................................................................................................................... 51
• AD INDEX ................................................................................................................................... 62