Willsenton R8: Push Pull Global Negative Feedback Tuning.

In this final mod segment, I explore adjusting the Global Negative Feedback, or GNFB for short, on this vacuum tube amplifier. Using a scope + the Analog Discovery 2 with the audio analyzer suite software, I work to get a clean square wave, avoid instability/oscillations that can kill your speakers/tweaters and at the same time not kill off power.

This is a video series about the popular Willsenton R8 KT88 EL34 Push Pull tube audio amplifier. We will go through the repair this amp needs, testing and reviews of the amp as delivered, and then work on modifications to improve the sound quality and durability.

A great book for DIY amp building info!
Morgan Jones: Building Valve Amplifiers.
https://amzn.to/3X2hKfk

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https://amzn.to/3Q3Ynjr

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