Single-Ended 807 Amplifier


This amplifier was built on-the-cheap. I used salvaged transformers purchased well below online prices and 807 tubes which are still reasonably priced. 7 watts per channel. I won an impromptu local “shootout” with this. Recently added speaker/headphone switch and headphone jack. Now it’s personal!


How it was done: Single-ended pentode mode, with primary-side feedback, and fixed bias operation.

A look at the construction:


2 thoughts on “Single-Ended 807 Amplifier

  1. Ah, look again! It’s a fixed bias circuit, not cathode bias. The 10 Ohms are present for allowing the current level to be measured (50ma = .5V). Very little degeneration at 10 ohms, bypass isn’t needed. Ignore the schematic comment, it’s .5V not .05V.

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