hifisonix

Tag: distortion

  • RIAA Equalizer Amplifier Design

    This article explores the fundamental’s of phono amplifier design,  culminating in a few practical designs. Special emphasis is placed on overload margins (critical if you want good sonics from your EQ amp), driving the EQ network adequately and noise. RIAA Equalization Amplifiers V2.0 Below is the RIAA Calculator Excel spread sheet.  Please read the article above,…

    Read more

  • Amplifier History: The JBL SA-600

    The beautifully styled JBL SA-600 amplifier was launched by the James B. Lansing company in 1966, and Bart Locanthi (the designer) wrote the  technical article (link further down) in January 1967.  This is one of the earliest – if not the earliest – example of a commercial  amplifier that addressed the potential for TIM/SID and…

    Read more

  • Solid State Feedback Amplifiers: A Short History

    “Why, sometimes I’ve believed as many as six impossible things before breakfast.” ― Lewis Carroll, Alice in Wonderland     A Future Without Feedback by Martin Colloms There is no mysticism in amplifier design, just serious science. —Andrey A. Danilov Introduction You will recall from the The Theory of TIM by Matti Otala elsewhere on this site,…

    Read more

  • Class A Buffering the Correct Way

    Here’s a simple way to force an opamp output stage to run in class A when used with a discrete buffer output stage – it takes just 1 resistor to provide a near constant current source load. Operating the opamp (and the output buffer stage) in class A dramatically reduces harmonics on the power rail…

    Read more

  • Hifisonix ‘Symphony’ Line Preamplifier

    I designed and built this preamplifier while living in Taiwan a few years ago. The Symphony preamp features Baxandall tone controls, up to 7 inputs,  a class A 2 W headphone amplifier and a Goldpoint 24 position attenuator.  The write-up describes the design process and choices in some detail and my listening impressions: Part 1…

    Read more

  • Ovation e-Amp: A 180 Watt Class AB VFA Featuring Ultra Low Distortion

    The e-Amp is a 180 Watt RMS (very conservatively rated into 8 Ω ) fully balanced symmetrical (‘FBS’) amplifier featuring an emitter follower triple (EFT) bipolar output stage and beta enhanced VAS stage. The amplifier can be configured using jumpers for TMC (Transitional Miller Compensation) or straight Miller compensation (MC). The VAS can be lightly…

    Read more

  • 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…

    Read more

  • 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…

    Read more

  • The Theory of TIM – Matti Otala

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

    Read more