Perimeter Monitor:  Using a single cable such as speaker wire or doorbell cable, this circuit can be remotely positioned, for example, at the bottom of a garden or garage, and used to detect all sound in that area. The cable can be buried in a hosepipe or duct and is concealed out of sight. The mic is an ordinary dynamic mic insert and should be housed in a waterproof enclosure with the rest of the circuit. (Electronic Schematic / circuit added 4/02)

Portable Microphone PreAmplifier:  High headroom input circuitry. 9V Battery powered. (Circuit / schematic design added 6/06)

PreAmplifier Computer Microphone:  adapting electret microphone to soundcards with dynamic microphone inputs (Electronic circuit added 5/02)

PreAmplifier for Microphone or guitar use:  suitable for guitar or microphone use. (Electronic circuit added 7/03)

Radio Shack Pressure Zone Microphone (PZM) Modifications:  (Electronic Schematic / circuit added 4/02)

Rane MS 1B Microphone PreAmplifier Circuit Diagram:  This is a circuit diagram of a commercial high quality balanced microph1-preamplifier. This document is in PDF format. (Electronic circuit added 5/02)

Simple microphone preAmplifier #2:  This is a simple microphone preamplifier circuit which you can use between your microphone and stereo amplifier. This circuit amplifier microphone suitable for use with normal home stereo amplifier line/CD/aux/tape inputs. This microphone preamplifier can take both dynamic and electret microphone inputs (preamplifier provides power foe electret microphone elements). The idea of this circuit is to keep the design as simple as possible to be easy to build. That was my goal when I needed a simple external microphone preamplifier for my mixer. The performance of the circuit is nothing superior but can be used with many not so serious projects....  (Electronic circuit added 4/05)

Simple microphone preAmplifier:  (Electronic circuit added 4/05)

Simple Stereo Electret Microphone PreAmplifier:  (Circuit / schematic design added 6/06)

Sony C 37Condenser Microphone:  information with circuit diagram (Electronic circuit added 5/02)

Speaker Microphone:  circuit that allows you to use a cheap loudspeaker as a poor microph1- (Electronic circuit added 5/02)

Standard Microphone PreAmplifier Input Circuitry:  PDF file (Circuit / schematic design added 6/06)

Stereo Electret Microphone PreAmplifier:  (Circuit / schematic design added 6/06)

The Big-E Stereo Parabolic Microphone:  This device is a stereo amplifier for a high sensitivity stereo parabolic microphone. It can be used for listening to distant sounds. Typical parabolic microphones are monophonic, this unit has a stereo audio path that helps produce more realistic sounding audio. The Big-E can be used with headphones or as an audio source for a stereo tape recorder or a PC sound card. This circuit also works nicely as a remote stereo audio receiver for accompanying a video surveillance system. It is capable of operating on the end of a four wire shielded cable that is more than 100 feet long. For remote operation, a set of inexpensive amplified PC speakers can be connected to the outputs for monitoring the sound....   (Circuit / schematic design added 6/06)

The scoop on Java:  11/07/96 EDN-Design Feature / (added 2/06)   Java is a programming language. Java is object oriented. Java is byte code. Java is an operating environment. Java is processor independent. Java is marketing hype and an enabling technology. Java is all the above and more. —Markus Levy, Technical Editor

Theory and Construction of MIC Splitters:  (Electronic Schematic / circuit added 4/02)

Transformerless Microphone PreAmplifier :  (Circuit / schematic design added 6/06)

Tube Microphone Preamp:  (Circuit / schematic design added 6/06)

Two Wire Remote Microphone Amplifier #2:  uses special amplifier module from Op-Amp Labs (Circuit / schematic design added 6/06)

Two Wire Remote Microphone Amplifier:  uses special amplifier module from Op-Amp Labs (Electronic circuit added 5/02)

Vacuum Tube Microphone Preamp :  from January1997 EQ Column, includes phantom power supply (Circuit / schematic design added 6/06)

Vacuum Tube Microphone Preamp/Direct Box Project:  from January 1997 EQ Column, includes phantom power supply (Electronic circuit added 5/02)

Voice over Circuit:  Switches automatically from sound source to microph1-when enough sound comes in from microphone. (Electronic Schematic / circuit added 4/02)

Wireless Microphone #4:  (Electronic circuit added 4/05)