Searching for a Unicorn Part 2: Generating a Good Signal Source

In this second article, Brian Lowe (Belleson LLC) continues his search for the Unicorn of "Measuring Voltage Regulator Ripple Rejection," this time focusing on the test fixtures. Testing a voltage regulator with exceptionally good performance requires an even more exceptional signal source and measurement setup to measure sub-microVolt ripple across a wide frequency range. Complementing the final article, Jan Didden, offers an informative sidebar about super regulators. This article was originally published in audioXpress, June 2019.

In this article Brian Lowe shares a fascinating journey in his search for a "Unicorn" that is measuring voltage regulator ripple rejection - or power supply rejection ratio (PSRR). Lowe is the founder and principle engineer at Belleson, LLC, and he has devoted a lot of time to this fascinating "quest." This article was originally published in audioXpress, May 2019.

Stuart Yaniger wrote a great article for audioXpress in February 2009, The ImPasse Preamplifier, describing a tube preamp to drive a pair of Nelson Pass’ First Watt F4’s (or other low-to-unity-gain power amplifiers) in balanced mono. Yaniger’s preamp is truly an elegant design with very, very low distortion, using a 6SN7 to drive a 6922 in balanced mode. There are LED’s, NE2H neon lamps and depletion MOSFETs in the design.

A great solid-state project where National Semiconductor’s (since 2011, a part of Texas Instruments) LM4702 meets up with Renesas lateral MOSFETs, this article by Jack Walton was originally published in audioXpress July 2007 and it is still cited as a reference today. An ideal project for the DIY enthusiasts.