A Non-Complementary Audio Noise Reduction System:  National Semiconductor Application Note   (app note added 6/06)

AN-337: Reducing Noise on Microcomputer Buses:  National Semiconductor Application Note   (app note added 6/06)

AN-386: A Non-Complementary Audio Noise Reduction System:  National Semiconductor Application Note   (app note added 6/06)

AN-4148 / Audible Noise Reduction Techniques for FPS Applications:  Fairchild Application Notes / (app note added 6/06)

Audible Noise Reduction Techniques for FPS Applications / AN-4148:  Fairchild Application Notes / (app note added 6/06)

Audio Notch Filter :  A variable notch filter with both high and low pass filters.  For audio frequencies 100Hz 10KHz  (added 11/05)

Burwen DNF1201Dynamic Noise Filter:  Schematics and Lineup Instructions (added 5/02)

Circuit Eliminates Hum from Pulsed Signal:  01/20/94 EDN-Design Ideas / (added 3/03)  The circuit eliminates hum from a periodic signal by a factor of as much as100:1. Fig2a shows an incoming signal that combines a periodic square wave and a much lower frequency hum. Suppose for simplicitys sake that the hum is sinusoidal.

Circuit Reduces VCC Ripple in Audio Band:  01/18/96 EDN-Design Ideas / (added 08/05) The circuit in Figure 1  reduces noise and ripple by at least 35 dB over the audio range of 100 Hz to 20 kHz. The circuit provides a clean source of 5V power for driving audio circuits in portable applications such as cellular phones and multimedia notebook computers. Most linear regulators reject noise only to about 100 Hz, and the bulk of a low-frequency passive filter is unwelcome in portable applications.

Digital Filter Makes Simple SPICE Eliminator:  04/10/97 EDN-Design Ideas / (added 3/03)  

Digital Noise Reduction Techniques for Combo Ii:  National Semiconductor Application Note   (app note added 6/06)

Filtering PC Bus Power:  (electronic (schematic / circuit added 4/02)

GalaXY Noise Filter:  (electronic circuit added 7/03)

Hum Bucking and Noise Reducing Electronics for Guitars:  (electronic (schematic / circuit added 4/02)

Hum Filter:  (project / circuit added 11/06)

Noise Filtering and the ADT7461:  AN-699 Analog Devices Application Note   (app note added 6/06)

Non Complementary Audio Noise Reduction System:  National Semiconductor Application Note 09-Apr-1996 (app note added 4/02)

Reducing Noise on Microcomputer Buses:  National Semiconductor Application Note   (app note added 6/06)

TB-02: Digital Noise Reduction Techniques for Combo Ii:  National Semiconductor Application Note   (app note added 6/06)