The only part left was the discharge transistor; a pentode was enlisted to stand in for that vital function, making the circuit complete. To physically implement the design, [David] built a large ...

If your first thought is that he must have made a flyback converter to step that voltage up to something more useful then you’re in for a surprise, because the single 6J6 pentode really does run ...

What you're looking at is the Audio Research Reference 330M power amp, a fully balanced, pentode-mode monoblock ... stands for Junction Field-Effect Transistor, a semiconductor device that uses ...