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Digital Control of an Analog Parametric Equalizer

This project focuses on creating a digitally controllable analog band-pass filter with an adjustable resonant frequency for a middle frequency adjuster in an audio equalization stage. The design of the band-pass filter is a standard series resistor, inductor, and capacitor filter network. An adjustable gyrator circuit simulates an inductor to change the resonant frequency of the filter. Inside the gyrator circuit, a voltage-controlled amplifier is configured to simulate a resistor to change the gyrators simulated inductance. A digital to analog converter controls the gain of the voltage-controlled amplifier to make the analog filter digitally controlled. This circuit successfully acts as a bandpass filter with a digitally controllable resonant frequency.

Author: Conner, Blair Ryan
Affiliation: Purdue University
AES Convention:131 (October 2011) eBrief:22 Import into BibTeX

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