For
Anyone caught between two camps
You will learn
  • See why even-order harmonics cancel in push-pull
  • Hear class A vs AB vs B in the spectrum
  • Read 'warmth' and 'punch' as harmonic content
Before you start
Time & level
6 minBeginner
Next step

By

Beginner · Topology demo

Single-Ended vs Push-Pull — the demo

Three sliders settle thirty years of audiophile religion. Same sine, two topologies, the spectra answer.

Single-Ended vs Push-Pull — the demo

Same sine, two topologies. Drive harder, change bias class, add feedback. Watch the waveforms and the harmonic spectra answer back.

Drive80%
Bias class
Feedback0dB
Single-ended (SE)
asymmetric clipping → 2nd dominant
FH2H3H4H5H6H7H8
Push-pull (PP)
symmetric → 2nd cancelled, 3rd dominates
FH2H3H4H5H6H7H8
Reading the result

SE clips one half harder, building a strong 2nd harmonic — that's the famous warmth. Push-pull is symmetric by construction, so even-order harmonics cancel ; what's left is mostly 3rd, perceived as 'punchy' or 'edgy' near clipping. Class B sharpens the corner ; class A keeps both tubes always conducting and stays the cleanest.

Toy analytical model — real amps add output transformer, feedback loops, and supply sag. Use it to *see* why even-order cancellation happens, not to predict the actual SPL spectrum.