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 […]

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Opamp Noise Visualizer

This Excel spread sheet tool was developed from one by Steve Hagman (www.AnalogHome.com) and allows en and ien data for up to 7 opamps to be compared.  When using the tool, make sure you enter comparable data – so for example,  always use the same frequency to make the comparison.  I normally use 1 kHz […]

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Tom D Kite Busts Some Audio Myths!

Ever wondered how we got to ‘feedback is bad’, ‘ . . . sampling destroys the music’  or  ‘ . . .  analog is 40 bits resolution . . .’  ,  ‘we need damping factors of 1000’  and   ‘ . . . only vinyl sounds good’ ?  Tom D Kite PhD, of Audio Precision, takes […]

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AN-597 Current Feedback Amplifiers

This National Semiconductor application note was written by Hans Palouda and published in 1989. It explains basic CFA operation clearly and concisely. AN-597 Current Feedback Amplifiers Here are some other useful application notes and articles that may help in developing an understanding of amplifier topologies and their associated trade-offs. wiki https://en.wikipedia.org/wiki/Current-feedback_operational_amplifier EDN https://www.edn.com/design/analog/4458753/In-defense-of-the-current-feedback-amplifier ADI https://www.analog.com/media/en/training-seminars/tutorials/MT-034.pdf TI https://cas.ee.ic.ac.uk/people/dario/files/E416/OA-30.pdf     […]

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