The ax-Amplifier: A 60W RMS Class A Amplifier featuring AFEC
in Power amplifiers
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 The ax-Amp is a […]
Imroved Soft Start + DC Blocker aka iSSDCB
in Power amplifiers, Power supplies
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 […]
Hifisonix X-Altra Mini II Line Preamplifier with Remote Control
in Preamplifiers
Originally published in January 2022. The Remote Control board optionally replaces the manual select control board to provide full remote control functionality on the preamplifier. The remote control board has a H-bridge output to drive a motorised ALPS RK27 or RK16 20K log taper potentiometer (5V at 100 mA) and is short circuit proof. Further, […]
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 X-Altra RIAA Phono EQ Preamp
in Vinyl preamp
This project was published in two parts in the influential US-based audio magazine ‘audioXpress’ in February and March 2021 (links to the download page below). About sixty of these preamps have been built as of May 2023. You can buy a set of X-Altra MC/MM preamplifier boards for $49.50 + $15 for shipping over in […]
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 […]