hifisonix

Tag: preamplifier

  • Hifisonix X-Altra Mini II Line Preamplifier with Remote Control (Deprecated)

    The X-Altra Mini II has been discontinued as a complete project. The individual PCBs are still available over in the shop however and are great line stages and power supplies. The X-Altra Mini II is a superb preamplifier and it sits at the heart of my system, but it was complex with lots of inter-module…

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  • Hifisonix Standard PSU

    Click here to buy a PCB for the Standard PSU Click here for the build documentation Click here for the BOM The Hifisonix Standard PSU features low noise, up to 400mA per rail output current, a MUTE relay driver to ensure when the load powers up or down there are no clicks or thumps, a…

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  • 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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  • Baxandall’s Original Tone Control Article from Wireless World 1952

    This article was published in October of 1952, when Baxandall was 31 years old, the design having already won him a prize 2 years earlier in a competition. His design basically relegated other tone control circuits to the scrap heap, although cheap passive, or non-inverting circuits still persisted well into the 1980’s, especially in low…

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  • OPEX-1: A Discrete OPAMP for Audio

    This design showcases a discrete opamp for audio applications.  It features very low noise, low distortion and a class A output stage that will deliver 1ppm distortion into a 600 Ohm load at 12 V peak. OPEX-1-Discrete-Opamp

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