Hifisonix kx2-Amplifier
in Power amplifiers
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 […]
Hifisonix nx-Amplifier: A High Performance 100 W class AB Current Feedback Amplifier
in Power amplifiers
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 […]
Hifisonix sx-Amplifier: A 15 W Class A Current Feedback Amplifier
in Power amplifiers
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 […]
Hifisonix Soft Start + DC Blocker for mains
in Power amplifiers, Power supplies
You can buy a DSTHP PCB for the Soft Start DC Blocker over in the Shop. Large (300 VA and above) Toroidal transformers suffer from high in-rush currents if they happen to have mains applied when the AC voltage cycle passes through zero volts. On a 1 kVA transformer, this can exceed 100A. Added […]
Hifisonix Micro Ripple Eater
in Power amplifiers, Power supplies
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 […]
Hifisonix Speaker Protection Board
in Power amplifiers
You can buy a Hifisonix Speaker Protection Board over in the Shop. This simple, low cost speaker protection board uses the ubiquitous UPC1237 from Unisonic, a Taiwan based semiconductor manufacturer. The circuit will work from 25V through to 75V and uses mosfets to switch the speaker load rather than relays which are problematic and unreliable. […]