Audio preamp sirkuit

Altec 1564A Preamp Power Supply

Altec 428B Microphone Preamplifier schematic

API 321 mic preamp schematic

Application note showing RIAA phono preamplifier based around the National LM833 (PDF)

Audio preamp

Audio preamplifier

Balanced microphone preamp

Basic low frequency preamplifier circuits

Bat detector microphone pre-amplifiers

Collection of phono preamplifier circuits

ECM Mic preamp

Electret mic amplifier

FET Preamp Cable

General purchase audio preamplifier based on pair of 2N2222 transistors

Hi Fi preamp

Hi-Fi Preamp with remote-control and other advanced features

High quality audio preamplifier (OPA2134)

Intercom preamp

Low impedance microphone amplifier

Low Noise Microphone Preamplifier

Magentic phono cartridge phono preamp circuit diagram

Microphone preamp for portable transceivers

Microphone pre-amp with high emphasis

Neumann U67 microphone preamp power supply

RCA BA-1A two-stage preamp schematic

RCA BA-21A preamplifier schematic

RCA BA-31A preamplifier schematic

Selection of audio preamplifiers including circuits suitable for battery operation

Simple Car Preamplifier and Artificial Earth

Simple Microphone Preamplifier

Simple microphone preamplifier

Simple microphone preamplifier

Simple transistor preamp - includes a PCB layout

Sound card microphone preamplifier

Ultra-Simple Guitar Preamp

Vacuum Tube Microphone Preamp

Voltage follower with 1G ohm input resistance based on LM11 opamp