Stereo Circlotron OTL Project Circlotron OTL Schematic 12-3-2018.pdf is a continuation of my experiments with the circlotron output topology.This article is about building your own all-FET Circlotron. Bridge” more accurately describes the topology and makes for less hocus-pocus. And, since. THE AMAZING FET CIRCLOTRON 2008 Michael Rothacher Cue the Theremin music! Bridge more accurately describes the topology and makes for less hocus-pocus. Thank Mjolnir's Crossfet™ circlotron-style output stage. It's unique in the headphone amp world, and it delivers both excellent performance and low. Fashion occurs in electronics, as well. This circuit uses the Cascode's topology to increase greatly the gain of this circuit.