Linear Audio Volume 4 is the fourth issue of a series of printed bookzines dedicated to technical audio and perception. The international team of authors for this issue again offers technical audio articles on a wide ranging number of subjects, from tutorials to circuit and system design, to projects and test reports, to book reviews. In this volume:
In The case for subjective Listening Tests, Dr. Hans van Maanen argues that there is a large body of circumstantial evidence for audible effects in audio equipment. Although not strictly ‘scientific’, this evidence can nevertheless be analyzed and used to determine promising avenues of development.
Burkhard Vogel discusses The Glowing NoiseMaker - On the demystification of triode noise, developing some usefull procedures to calculate realistic triode noise figures, and appeals to tube manufacturers for more consistent data. Ian Hegglun makes progress towards a reconciliation of measurements with listening tests with a weighted distortion measurement protocol that much better matches subjective listening tests.
Nelson Pass gives an overview of Static Induction Transistors, from the vintage Sony and Yamaha VFETs to the exciting new PASS-SIT-1 device. Lennart Jarlevang, in Revisiting the SIT Nemesis gets his hands on a couple of PASS-SIT-1 devices and develops a single-ended, transformer output class-A amplifier with excellent sound. Finally, Alfred Hesener presents us with The “Terrible Twins” – a push-pull amplifier with solid state pentodes based on SITs.
Marcel van de Gevel shows us he is an equal opportunity designer with his elegant Tube based Phono Preamplifier, while Bob Cordell takes another approach with VinylTrak – A full-featured MM/MC phono preamp.
Les Bordelon takes a wider view of audio DAC system design, Building a Great Sounding DAC with a Little Help from My Friends.
John Walton cuts to the chase of myriad claims and reports on audibility of audio power supplies in A comparative overview of power supply regulator designs with listening tests and reaches some expected as well as unexpected conclusions.
The Way I see it
In Supply Decoupling – Finesse before Brute Force Stan Curtis explains how the indiscriminate addition of decoupling caps to a design can be counter-productive and that a few caps placed with finesse can be more effective and less costly.