Hifisonix X-Altra Mini II Line Preamplifier with Remote Control

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, […]

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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 X-Altra RIAA Phono EQ Preamp

Originally published in US based audio magazine ‘audioXpress’ in February and March 2021. You can buy a set of X-Altra MC/MM preamplifier boards for $49.50 + $15 for shipping over in the Shop.  The X-Altra MC/MM RIAA preamp is a state of the art design that brings new levels of performance to vinyl EQ featuring […]

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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 High Performance Balanced Line Stage

You can buy a stereo PCB for this line stage over in the Shop. This OPA1641 and OPA1642 opamp based stereo line stage, which is used in the X-Altra Mini II full feature line level preamplifier, offers a balanced output for the left and right channels and 2 unbalanced outputs each for the left and […]

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