The series of Audio Noise Reduction (DNR system)

This circuit can be use to audio noise reduction for use with audio playback systems. The DNR system is noncomplementary, meaning it does not require encoded source material. The system is compatible with virtually all prerecorded tapes and FM broadcasts. Psychoacoustic masking, and an adaptive bandwidth scheme allow the DNR to achieve 10 dB of noise reduction. DNR can save circuit board space and cost because of the few additional components required.

Skema Rangkaian Peredam Noise Audio (DNR system )

PCD layout DNR system

Features
Non-complementary noise reduction, “single ended”
Low cost external components, no critical matching
Compatible with all prerecorded tapes and FM
10 dB effective tape noise reduction CCIR/ARM
weighted
Wide supply range, 4.5V to 18V
1 Vrms input overload
Applications
Automotive radio/tape players
Compact portable tape players
Quality HI-FI tape systems
VCR playback noise reduction
Video disc playback noise reduction
Note:
The circuit system should always be placed before tone and volume controls. Placing DNR system after tone or volume control won’t work because any adjustment of these controls would alter the noise floor seen by the DNR control path.