The ax-Amplifier: A 60W RMS Class A Amplifier featuring AFEC

Parts 1 and 2 of the ax-Amplifier were published in the April and May 2024 issues of US based audioXpress magazine. Click on the link to visit audioXpress Click this link to order 2 off ax- Amplifier PCB’s https://hifisonix.com/shop/2-off-ax-amplifier-module-pcb/ You can order copies of audioXpress here audioXpress Magazine Subscription – CC-Webshop Here is a short […]

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Imroved Soft Start + DC Blocker aka iSSDCB

The original Soft Start + DC Blocker published on this website a few years ago required quite complex wiring encompassing both the mains supply to the transformer and wiring from the rectified and DC-smoothed secondary.  Additionally, the mains power switch had to be rated for the full primary AC load current which placed severe limitations […]

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Hifisonix kx2-Amplifier

Originally published in January 2020. The hifisonix kx2-Amplifier features outstanding distortion and noise performance, coupled to switchable class A, AAB or AB operation. It delivers 28 W peak (15W RMS) class A into 8 ohms at less than 20 ppm distortion, and >80 watts RMS into 2 Ohms at 0.2% distortion. The compact PCB measures […]

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Hifisonix nx-Amplifier: A High Performance 100 W Class AB Current Feedback Amplifier

Originally published in December 2012. This power amp design is based on the sx-Amplifier topology, but with the TIS and output stage re-configured for class AB operation, enabling it to deliver 100 W into 8 Ohms. I have kept the design very simple, retaining the CFA topology, providing a very wide -3 dB bandwidth of […]

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Hifisonix sx-Amplifier: A 15 W Class A Current Feedback Amplifier

Originally published in August 2012. Update January 2018: For the sx-Amplifier, you can  buy a complete set of very high quality Double Sided THP Gold Flashed PCB’s from Jim’s Audio here: sx-Amplifier DSTHP Gold Flashed PCB Set About 150 sx-Amplifiers have been built world-wide. As you can read about in the PDF below, my class […]

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Hifisonix Micro Ripple Eater

You can buy Micro Ripple Eater boards in the Shop This simple ripple eater (aka MRE) can deliver up to 10A per supply rail (provided it is suitably heatsinked!) and will reduce mains related ripple on amplifier supply rails by up to 40 dB and as much as 50 dB at HF. The board is […]

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