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Articles

Welcome to our articles page, where you’ll find a wealth of information on everything audio-related. Our articles cover various topics that will appeal to audiophiles of all levels.

  • The New nx2-Amplifier: a 100W CFA Power Amp

    The New nx2-Amplifier: a 100W CFA Power Amp

    A new high performance 100W CFA amplifier. The nx2 produces >100W into 8 ohms and >200W into 4 Ohms both channels driven. At 100W into 8 ohms, the measured distortion is below 30ppm while at 200W, it is below 40ppm. The amplifier features 700ns rise/fall times and an EF2 output stage using three pairs of…

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  • Ovation 250 Power Amplifier

    Ovation 250 Power Amplifier

    The Ovation 250: A 250W per Channel Audio Power Amplifier (updated 1st June 2013). This amplifier was designed and built in 2005/2006 as my first foray back into audio design after a nearly 20-year hiatus, This write-up was originally published in 2009 when I was living in Tokyo, Japan. Introduction Diy Audio is a wonderful activity:- …

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  • Audio Power Amplifier Design – Peter J Baxandall

    In this 6 part series of articles published from January 1978 in the now defunct Wireless World magazine, Peter Baxandall takes the reader through some of the fundamentals of audio amplifier design as they were understood at the time. Baxandall_Audio Power Amplifier Design In 1978  there was still much discussion about feedback and how to…

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  • Douglas Self’s 8 Distortions and a Few More

    (pictured above is the hifisonix 180 Watt per channel e-Amp) No one had codified all the major audio amplifier distortion mechanisms until  Douglas Self published the first edition of his ‘Audio Power Amplifier Design Handbook’ or APAD’ as it has become known, in 1996.  He used a standard Lin* topology amplifier and then proceeded to…

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  • The Theory of TIM – Matti Otala

    Matti Otala  follows up on earlier research on the subject of TIM. The Theory of TIM Matti Otala

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  • Some Ideas on Temperature Compensation for Audio Amplifier EF Triples

    Temperature compensating an EF3 audio power amplifier output stage is not a trifling task.  There are 6 Vbe junctions, running at 3 different current densities, different temperatures and neither is the thermal performance of the heatsink assembly characterized in most DIY cases. This makes deploying a conventional 2 transistor  Vbe spreader (or Vbe multiplier as…

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  • Review of Bob Cordell’s Book ‘Designing Audio Power Amplifiers’

    ‘Designing Audio Power Amplifiers’ by Bob Cordell  – Reviewed by Andrew C. Russell in 2011 Bob Cordell (on the right) pictured with Jan Didden, publisher of ‘Linear Audio’ After a 15 year hiatus from electronics, I returned in 2005 to linear design not as a professional but as a hobbyist. Earlier in my career, I…

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  • Saturn V Rocket Performance Report

    Absolutely nothing to do with audio, but a great read for the techies. This performance report was pulled together in the late 1960’s by Walter Haeussermann , one of the German rocket scientists who went to the US after WWII, where he settled and went on to have a spectacularly successful career with NASA.  He…

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  • CFA Diamond Buffer IPS: Does it Operate in Class B or class A?

    There is a persistent assertion by small group of amplifier design practitioners that the diamond buffer input stage of CFA audio amplifier operates in class B (or AB) mode wherein there is a hard ‘handover’ between each half of the diamond buffer input stage as the input signal passes through 0V.  The most recent claim…

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  • Barney Oliver: Crossover Distortion in Class B Audio Amplifiers

    This is the famous analysis of class B amplifier cross-over distortion by the then head of HP Reasearch Labs, Dr. Barney Oliver,  published in the February 1971 edition of the HP Journal.  The  bias current Iq for a class B emitter follower amplifier is shown to be approximately  Iq = .026/(Re+re+(rb/hFE)). In practice,  – the…

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