David Berning on the history and technology of ZOTL & OTL amplifiers

David Berning, the inventor and designer of the patented Zero-hysteresis Output Transformerless (ZOTL) circuit on which all Linear Tube Audio amplifiers are based, gives a detailed history and technical explanation of ZOTL as well as traditional output transformerless (OTL) amplifiers.
Get out a pen and paper, folks, this gets technical. But it's all presented in David's amiable and imitable style.
Thank you to the San Francisco Audiophile Foundation for the opportunity to give this presentation to their membership and making it available to the public. Check them out on KZbin: ‪@sanfranciscoaudiophilesoci3023‬ and at their website: sfaf.clubexpress.com/
0:00 Intro
4:23 History of Output Transformerless (OTL)
24:26 The Berning ZOTL Amplifier
1:02:42 - The OTL and Single-ended Implementation
1:14:41 Q&A
To learn more about David Berning, the ZOTL circuit, and his amplifiers: davidberning.com/
To learn more about Linear Tube Audio and their ZOTL amplifiers: