CFA vs. VFA: A Short Primer For the Uninitiated

This article was written in 2014 in response to what can only be described as a vitriolic debate as to what constituted a CFA on diyAudio.com.  At the time, many of the participants were struggling to grasp the fundamental differences between VFA’s and CFA’s, and even how to tell them apart.  So, this document is […]

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Output Coupling Inductors

Inductors on the output of an amplifer are used to isolate the amplifer from capacitive loads at HF and ensure stability.  There has been quite some debate on DIYaudio.com as to whether they are audible, necessary, or just the result of designers being overly cautious.  Some very well known designers in the field have decided against using […]

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A Concise Overview of TIM by Bob Cordell

This set of articles was written in the early 1980’s by Bob Cordell, a few years after Matti Otala (RIP) identified TIM (Transient Inter-Modulation) as the probable cause of sonic imperfections in high feedback solid state amplifiers in the 1970’s. Otala’s paper sent shock waves through the amplifier design community but sadly it ended up […]

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