Output Stage Topology
Output stage topology describes how the tubes or transistors supplying power to your speakers are arranged in each amplifier channel.
Single-ended uses one signal-handling output device for the whole waveform. Parallel single-ended uses several devices doing this together. Push-pull uses two sides driven oppositely: the signal drives one toward more current and the other toward less. Parallel push-pull places multiple devices on each side.
Output Stage Topology — Power Amp
Push-pull can operate in Class A: both sides then conduct throughout the waveform, rather than each conducting for only half. On amplifiers combining tubes and transistors, the topology label describes the output stage.
Topology does not specify connectors, bridge mode or output-transformer presence. Class D, bridging or a device count alone cannot identify one of these arrangements. Nor does topology rank sound quality: check output-power ratings and their speaker-load conditions to assess speaker matching.
Sources
- The Zen Amplifier: single-ended operation — Nelson Pass / Pass DIY
- Leaving Class A: push-pull conduction — Nelson Pass / Pass DIY
- Conquest: parallel single-ended output stage — Audio Note (UK)
- P-4200: parallel push-pull output stage — Accuphase