The Amazing FET Circlotron Construction, Continued — Michael Rothacher / 2008

A lot of would-be audio projects die on the vine, even when printed circuit boards and components are readily available. The planning, layout, and construction of the chassis metalwork are sometimes the barrier. Perhaps, this is why complete kits are often the first choice of beginners. To get you building, I’m including some additional information, a few instructions, pictures, and a parts list. Wherever possible, I’ve tried to select suppliers who have online stores so you can just “click” your way to a complete kit of parts. The Chassis To simplify construction of the FET Circlotron we’re going to go… More...

Super-Symmetric Amplification — Nelson Pass / 1998

U.S. Patent # 5376899 describes a new amplifying circuit topology that takes advantage of the character of special matched balanced amplifiers that are cross-coupled to provide cancellation of distortion and noise. The result provides high performance with very simple linear circuits, better than previous efforts by an order of magnitude. We have dubbed the approach Super-Symmetry (Su-Sy), an homage to particle physics. Super-Symmetry works by exploiting the complementary characteristics of precision matched balanced circuits to differentially reject distortion and noise, and extends this symmetry to make the distortion and noise virtually identical on each half of a balanced amplifying circuit.… More...