Biasing Double-Ended Amplifier Output Tubes, Part 1: Basic Explanation & Methods

In this Part 1 of 2 videos, I will describe two different methods to measure the output tube bias (Plate Dissipation) of double-ended (DE) tube amplifiers, and one method to adjust the bias of cathode-biased DE circuits. I will also present insights into how to read and interpret amplifier schematics to assist you in performing your own biasing procedures. For best comprehension, it is strongly recommended that you first view my previously-posted video covering the biasing of single-ended cathode-biased amps. In the Part 2 video, I will demonstrate the DE biasing procedure and will describe the most common methods to adjust the bias of grid-biased DE circuits, and a second and more accurate way to adjust the bias of DE cathode-biased circuits. Throughout the demonstration, safety rules will be emphasized. NOTE: When biasing cathode-biased output tubes, the Plate Voltage should be measured from plate to cathode to obtain the “net“ PV for determination of accurate Plate Dissipation. If y