Chapter 10

Noise reduction techniques

Almost all signal handling stages will introduce some unwanted extraneous components. When these unwanted signals are unrelated electrically to the wanted one they are generally termed ‘noise’, and recording processes are particularly prone to this type of problem. This can arise as a result of mechanical imperfections in the recording process, which can introduce ‘rumble’ – low-frequency noise characteristic of motor bearings – or ‘hum’, due to the stray electrical fields from the AC mains supply or from AC ripple, due to inadequate smoothing in the power supply system. Alternatively, and more commonly now that thermionic valves have been replaced by solid state amplifying devices, the noise will take the ...

Get Audio Electronics, 2nd Edition now with O’Reilly online learning.

O’Reilly members experience live online training, plus books, videos, and digital content from 200+ publishers.