MAGNETIC_PICKUP_PREAMP

Published:2009/7/6 5:50:00 Author:May | From:SeekIC

Circuit uses type 747 dual opamp, but individual 741 opamps may be used instead. Input signal is first amplified flat, after which equalization acts on both signal and noise to give improved S/N ratio. Adjust first opamp for gain of 13. Series feedback is used to minimize noise since impedance of magnetic pickup is low compared to opamp input impedance. Second opamp has frequency-dependent series feedback for RIAA compensation. Gain here is unity at 1 kHz. Out-put is about 70 mV for modern pickup having output of about 5 mV.-B. S. Wolfenden, Magnetic Pick-Up Preamplifier, Wireless World, Sept. 1976, p 81-82.



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