Many Beta VCRs have a circuit that removes unwanted hiss from the normal (linear monaural) audio track. Called BNR (for Beta Noise Reduction) it uses a strategy that compresses and expands the audio signal similar to the Dolby® and DBX® noise-reduction systems. This processing reduces the high volume hiss generated by residual magnetization. It is always present in the fine oxide grains that are imbedded in the tapes emulsion. Some recorders have a switch for turning this circuit off. Also applies to linear stereo VCRs. ©Misterßetamax go to homepage