1.5 Volt AF Amplifier: A small single battery cell AF amplifier able to drive a Low impedance 8-Watt load up to15mW, built using discrete transistors

1.5 Volt Amplified Ear: Useful to listen in faint sounds1.5-Volt Battery operation, includes electret microphone preamplifier which runs from1.5-Volt DC and can directly drive32 Ohms impedance mini-earphones

10 Watt Amplifier:

10 Watt Power Amplifier: Simple Class A Amplifiers

100 Watt Amp Circuit:

100 Watt Audio Amplifier #1:

100 Watt Guitar Amplifier #2:

100 Watt Guitar Amplifier Mk2:

100 Watt RMS Amplifier: This is a100-Watt basic power amp that was designed to be (relatively) easy to build at a reasonable cost. It has better performance (read: musical quality) than the standard STK module amps that are used in practically every mass market stereo receiver manufactured today. When I originally built this thing, it was because I needed a100 WPC amp and didnt want to spend any money. So I designed around parts I had in the shop.

15 Watt 6V6 Guitar Amp (valve):

15 Watt Amplifier:

16 Watt Amplifier:

2 Channel Power Amplifier: The2-Channel Power Amplifier based on NTE1606. The circuit is powered by a12V,10-Amp power supply. The power of the output channels is4 W connected to 8-ohm loudspeakers

2 Transistor Amplifier:

2 Watt Amplifier 1:

2 Watt Amplifier 2: Low distortion amplifier using discrete components

2 Wire Remote Microphone Amplifier: uses special amplifier module from Op-Amp Labs

2.3 GHz Power Amplifiers:

20 DB Amplifier & High Current Balanced Line Driver:

20 Watt / Channel Stereo Power Amplifier:

20 Watt ClassPower Amplifier:

20 Watt GaAaFET Power on 2.3 GHz:

20 Watt Power Amplifier: Designed to be used as car amplifier

200 Watt Amplifier:

22 Watt Audio Amplifier: Simple stereo amplifier based on TDA1554

220 Watt Power Amplifier: This is a building plan for an audio amplifier with2 x220-Watt output power. Text is in Finnish.

2304 and 3456 MHz Power Amplifiers:

250 Watt Stereo Power Amplifier:

25L6 Amp: design without a power transformer

3 Band Equaliser:

3 Band Equalizer:

3 High Accuracy, RIA/ IEC, MC & MM Phono Preamplifiers:

3 Transistor Audio Amp 50 Milliwatt: Here is a little audio amplifier similar to what you might find in a small transistor radio.

30 Watt Power Amplifier: Ultra-Low distortion30-Watt Power Amplifier

300 Watt Subwoofer Power Amplifier:

4 Watt Amplifier:

45 Watt Single Chip Amplifier With Tone Controls:

50 Watt Amplifier:

55 Watt (Originally 75W) Power Amplifier:

60 Watt Into 8 Ohms Power Amplifier: A simple amp to build, uses commonly available parts and is stable and reliable

60 Watt Power Amplifier :

75 Watt Power Amplifier: AKSA is a highly refined push pull solid state stereo amplifier of 75-Watt per channel

8 Watt Amplifier:

8 Watt Audio Amp Based on LM383:

80 Watt Amplifier #1:

80 Watt Amplifier #2: Uses the LM12 chip

Active Subwoofer & Controller:

Active Subwoofer:

ALL FET MC Phono Preamp: Phono preamp with54 and 64 dB gain and RIAA accuracy is better than0.2dB, from Borbely Audio

AM Oscillator for Wireless Microphones:

Amplified Ear:

Audio Amp Output Power Limiter:

Audio Amp, Ultra High Gain:

Audio Amplifier Circuits:

Audio Amplifier Output Relay Delay:

Audio Amplifier: 2-Transistor Audio Amp

Audio Compressor: A circuit for a single-channel audio compressor using a JFET to control the gain of a virtual earth amplifier.

Audio Level Control Device: compressor circuit based on LED and photodiode

Audio Preamplifier:

Balanced Low Noise Microphone Preamp: very low noise, close to the theoretical minimum, high hum rejection and variable gain with a single rotary pot, similar to that used in many professional grade mixing desks

Basic FM Radio Transmitters:

BiDirectional 2.4 GHz One Watt Amplifier:

BiDirectional 900Mhz One Watt Amplifier:

Binaural MICs:

Boost 3.3V to 5V with tiny audio amplifier: 09/05/2002 EDN - Design Ideas / (added 10/03) This charge-pump circuit quietly converts a 3.3V source to 5V at 500 mA (figures 1 and 2). National`s (www.national.com) LM4871LD power amplifier makes this design idea both possible and practical, thanks to its low output resistance, low cost, compact size, and high dissipation capability. Its output resistance has an average value of 0..

Boundary Layer Dish Microphone: ideas for a directional microphone assembly.

Circuit combines power supply and audio amplifier: 12/20/2001 EDN - Design Ideas / The circuit in Figure 1 can help if you must transfer dc power and audio over a pair of copper wires. One application for such a circuit is a low-cost door-opening system with speech input. The circuit uses only one IC, the well-known LM317, a low-cost power-supply regulator. ... .

Computer Microphone: adapting electret microphone to soundcards with dynamic microphone inputs

Condenser Mic Audio Amplifier:

Condenser Microphone hookup:

Constant Power "PAN" Control: Circuit for Microphone for Microphone Audio Mixing

Crest Audio LT Series LT100, LT1500 & LT2000 Schematic Set: A commercial Class D Amplifier, complete schematics in PDF format.

Death of Zen (DoZ) a New ClassPower Amp:

Designing An OpAmp Headphone Amplifier: many circuit examples

DIY Microphone for Sony MD R35 Minidisc Recorder: simple electret microphone

Dual JT MB C Microphone Combining Circuit: connect tw1o microphones to1-microph1-input

Dual Microphones Separate Voice From Noise: 06/23/94 EDN-Design Ideas /

Dynamic Microphone Amplifier:

Dynamic Microphone to Electret Microphone Input:

ECM Mic Preamplifier:

el Cheapo a Really Simple Power Amplifier:

Electret Mic Apps: an electret MIC is the best value for money omni directional microphone you can buy for 90% of microphone application

Electret Microphone Connection: how to connect electret microphone

Electret Microphone Powering:

Guitar Amplifier 10 Watt: Old-Style ultra-compact Combo2-inputs-Overdrive-Treble-enhancement

HeadBanger Headphone Amp:

Headphone Amplifier #1:

Headphone Amplifier #2:

Headphone Amplifier #3:

Headphone Amplifier #4:

Headphone Distribution Amp:

Headphone Monitor Amp:

Hi Fi Class D Audio Power Amplifier: The purpose of this site is to share a pulse-width modulating Class D audio power amplifier design with the world, in order to involve people that have an interest in this kind of technology. This is in effect an "open source project", i.e. the design is open and free, and those that have the interest and ability, are encouraged to feed back into the project.

HiFi Headphone Amplifier:

High Sensitivity Hearing Aid:

Interfacing Microphones to Computer Sound Cards:

JLH Headphone Amplifiers:

Leach Amp 120 Watt Power Amplifier: Latest update of the "Low Tim Amplifier", Claimed to be a very good sounding design

Leach SuperAmp: 270-Watt Double Barreled Amplifier published in Audio magazine

Lidstr?m Improved ZEN I Class a FET Amplifier:

line Level Signal to Microphone Input Adapter:

LM380 Power Audio Amplifier: National Semiconductor Application Notes,04-Nov-1995

LM383 12 Volt Amplifier:

Low Cost Audio VChas High Performance: 01/19/95 EDN-Design Ideas

Low Level Audio Amp:

Low Noise Balanced Microphone Preamp: very low noise, close to the theoretical minimum, high hum rejection and variable gain with a single rotary pot, similar to that used in many professional grade mixing desks

Low Power Audio Amplifier Based on LM386:

Making a Rugged, Connectorized Microphone From a Panasonic Microphone Capsule:

Mega phone circuit 9v:

Micro Spy With FETs:

Micro Spy With TTL:

Micro Spy With USW:

Microphone Amplifier: