The Zeus Passive-Preamp/Line-Driver, also built in 2007.

Pair of Zeus75 amps, sitting on their power-supplies, built in 2007. The heatsinks are 300 x 200 x 85mm in size. These use the depletion MOSFETS, and run at about 60W bias.

My Zeus75 prototype, built in 2005. This runs with a higher B+ supply and the bias is set higher at 750mA per MOSFET, hence the much larger heatsink.

Pics of one of the two original Zeus35 power-stage amplifiers which I built in 1995. The pair of amps are still in daily use, unmodified from their original construction thirty years ago.

Audiophonics Introduction: My audio projects based around my transformer based amplification topology, which I started developing in 1994, now over thirty years ago! This audio-path implementation schematic shows depletion mode MOSFETs, eg IXTH20N50D, which auto-bias on the windings DC resistance.