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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Hifisonix X-Altra Mini II Discrete Line Stage

This is the discrete line stage used in the X-Altra Mini II line level preamplifier discussed in detail elsewhere on this website. The presentation linked to above discusses the design and presents the measurements of just the discrete line level amplifier. This is a paired down, simple design that nevertheless offers excellent measured performance and […]

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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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Hifisonix Speaker Protection Board

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. […]

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Hifisonix Standard PSU

You can buy a PCB for this power supply over in the Shop. If you are building a headphone amplifier, you can also buy a Standard PSU + HPA-1 Class A Headphone Amplifier PCB bundle in the Shop.  Here is a low noise general purpose linear power supply that can be used to power the […]

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Hifisonix X-Altra HPA-1 Class A Headphone Amplifier

You can buy PCB’s for the HPA-1 Headphone Amplifier over  in the Shop. There is also a Standard  PSU+HPA-1 bundle option as well in the Shop. The HPA-1 is a compact, very high performance class A headphone amplifier that will deliver up to 1.75W into a 32 Ohm pair of headphones. The amplifier features ultra-low […]

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