This circuit makes use of a low impedance microphone. The relay is according to the supply voltage which can be between 9 and 15 V. The operational gain is approximately 100.
Two potentiometers mounted at right angles, so that they can be operated by a lever, form a very...
This circuit is from a 2005 Linear Technology manual. The circuit uses an LT6700-3 and has an...
This circuit with RIAA equalization is from 1985 US documentation. The circuit has a flat response...