High Performance Audio Power Amplifiers

Appendix 3

Active devices

The following listings cover active parts – over 140 transistors and over 60 valves – that are common or notable in modern high performance audio power amplifiers, and that are subject to wearout, or otherwise in practice require occasional replacement.

In the following semiconductor listings (A,B,C), low voltage (<50v), small signal (<50mA) transistors are excluded, since after burning in, few will fail during the lifespan of the owner, or before the remainder of the amplifier rusts and rots away!

The majority of parts are ‘still current’, ie. in manufacture at the time of writing. The fact that some are 15 and up to 25 years old, shows not necessarily near-perfection, but also the lack of further work by semiconductor ...