The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 10, 1984
Filed:
Dec. 18, 1981
Sven Mattisson, Bjarred, SE;
Inventab Audio Kb, Luna, SE;
Abstract
An equalization amplifier (30) is disclosed which includes two amplifier stages (32, 34) connected in cascade. The first amplifier stage (32) includes a low pass filter amplifier (40) having a pole frequency of F1 and a feed forward path (36) bypassing the low pass filter amplifier. The feed forward path provides the input signal to an adder circuit (42) where it is added to the output of the low pass filter amplifier. The effect of this addition is to provide the first amplifier with a zero frequency of F2, where F2 is greater than F1. The resulting sum signal is applied to the second amplifier stage (34) which also has a low pass filter characteristic. The second filter has a pole frequency of F3, where F3 is greater than F2. The equalization amplifier is particularly useful for providing RIAA equalization of phono cartridge output signals.