🔍 Key Concepts

• Harmonic distortion in audio amplifiers and how even vs. odd harmonics are created • Operation of push-pull amplifier stages and how symmetry affects harmonic cancellation • The effect of keeping a tube (or transistor) in the linear region of its characteristic curve

💭 Think About

• How does a perfectly symmetrical push-pull stage treat even harmonics that are generated in each device? Think about what happens when the two halves of the waveform are combined. • If a single tube is biased so it only operates on the most linear part of its characteristic curve, what happens to distortion products, including harmonics? • Consider whether these two methods (push-pull operation and linear-region operation) address the same type of distortion or if one is more effective at canceling even harmonics specifically.

✅ Before You Answer

• Review how symmetry of the waveform affects even vs. odd harmonic content. • Check which method(s) are known in basic electronics to cancel even-order harmonics rather than just reduce overall distortion. • Verify whether both statements (A and B) are independently true about even harmonic reduction, or if one is more general distortion reduction rather than specific even-harmonic cancellation.