Hifisonix High Performance Balanced Line Stage
in Preamplifiers
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 […]
Hifisonix X-Altra Mini II Discrete Line Stage
in Preamplifiers
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 […]
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. […]
Hifisonix Standard PSU
in Power supplies, Preamplifiers
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 […]