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

1.5 Watt Audio Amplifier:

10 Watt Amplifier:

10 Watt Power Amplifier: Simple Class A Amplifiers

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.

120 Watt Power Amplifier #1: Text is not English

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 Audio Amplifier:

2 Watt Amplifier 1:

2 Watt Amplifier 2:

20 Watt / Channel Stereo Power Amplifier:

20 Watt Class a Power 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:

25 Watt Audio Amplifier:

25 Watt MOSFET Amplifier: High Quality simple unit. No need for a Preamplifier

250 Watt Stereo Power Amplifier:

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-Wattpower amp

300 Watt Subwoofer Power Amplifier:

4 Watt Amplifier:

50 Watt Amplifier:

50MHz Assistant (Preamp & Power Amp.):

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

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

Audio Amp Output Power Limiter:

Audio Amp:

Audio Amplifier Output Relay Delay:

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

BiDirectional 2.4 GHz One Watt Amplifier:

BiDirectional 900Mhz One Watt Amplifier:

Bridging Adapter for Power Amplifiers:

Brystom Power Amplifiers Circuit Diagrams:

Circuit combines power supply and audio amplifier: 12/20/01 EDN-Design Ideas / PDF contains multiple circuits - scroll to find this circuit

Class D Audio Power Amplifiers: 01/04/01 EDN-Design Ideas / Class D amplifiers are much more efficient than other Classical amplifiers, but their high efficiency comes at the expense of increased noise and distortion. You can assess the frequency- and Time-domain characteristics of a Class D amplifier, including the output filter, using online simulations.

Class T Digital Audio Amplifier Evaluation Board: This application note describes a digital amplifier, which operates from13.5-Volt power source and outputs up to20W poor channel power. The application note is in PDF format. Uses a Digital Power Processing Technology EB TA2020 from Tripath Technology.

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

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 Class a Power Amp:

Direct Injection Box for Recording & PA Systems:

Cheapo a Really Simple Power Amplifier:

HeadBanger Headphone Amp:

Headphone Amplifier #1:

Headphone Amplifier #2:

Headphone Amplifier #3:

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 back into the project.

Hi Fi Headphone Amplifier:

Hi Fi PC Speaker System:

Hi Fi Preamplifier:

High Performance Audio Applications of the LM833: RIAA Phono preamplifier stages and active crossover ne2-rks

Hiraga Le Classe a 20 Watt:

HJ 4P Professional Headphone Distribution Box: drives up to4 headphones from a single amplifier, has volume control and mono switch, product datasheet with circuit diagram in PDF format

HJ 6 Standard Headphone Distribution Box: drives up to 6 headphones from a single amplifier, product datasheet with circuit diagram in PDF format

Hybrid Amplifier using a 5687 Tube & Magnatec PowerMOSFETs:

Kumisa Mk. II Headphone Amp: DIY headph1-amplifier project using AD844 and some special transistors

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:

LM383 12 Volt Amplifier:

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 Noise Version of High Level Output Stage in 1031: PDF file

Low Power Audio Amplifier Based on LM386:

Lowlevel Audio Amp:

Microphone Phantom Power Supply:

MOSFET Power Amp: DIY high power MOSFET amplifier200 Wrms 8 ohms -350 Wrms4 ohms

MS Stereo Decoder:

MS Stereo Microphone:

One Watt 2.3 GHz RF Amplifier Using a MRF2001:

Personal Stereo Audio Amp:

Portable Headphone Amplifier: 3V Battery powered High Performance unit

Portable Microphone Preamplifier: High headroom input circuitry. 9V Battery powered.

Power Amplifier Clipping Indicator:

Power Follower: Less wasted power than true Class A but not as good sound

PushPull Class a 2A3 Stereo Amp:

Quadraphonic Amplifier: This is a four channel amplifier ideally suited for use with quadraphonic equipment such as a Sound Blaster Live card.

RIAA Equalized Stereo Phono Preamp:

Simple Amplifier:

Single Chip 50 Watt / 8 Ohm Power Amplifier: Uses LM3876 HiFi amplifier IC from National Semiconductor

Single Ended Class A2 SV81110 Stereo Amp:

Small Amplifier Circuit: Uses many amplifier ICs, from feWatt-Watts to200-Watt

SoftStart Circuit for Power Amps:

Spatial Distortion Reduction Headphone Amp:

Speaker Microphone:

Stereo Line Driver: Power Amp Stereo Line Driver

Stereo Tube Amplifier:

Subwoofer Equalizer: The Linkwitz transform circuit is a hugely flexible way to equalize the bottom end of a sealed loudspeaker enclosure. A speaker that is corrected using this method is flat from below resonance to the upper limit of the selected driver. The low frequency roll off point is determined by the parameters of the transform circuit. Should the enclosure size be too small and cause a lump in the response before roll off, this is also corrected. A conventional active crossover network is then used to divide the subwoofer signal from the main channel signals. Note that there is also a separate spreadsheet calculator available for calculating component values for different situations not handled by the original circuit.

Subwoofer Filter: 12 dB/octave low pass filter for subwoofer, includes subsonic filter

TDA2030 8 Watt Amplifier:

ThermoFan To Keep Your Amp Cool:

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

Tube Amplifiers:

Tube Buffer for CD Player:

Two 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

Two Transistor Audio Amplifier:

Two Watt Amplifier:

Underwater Microphone:

Voltage Controlled Amplifier:

Weighting Filter for Audio Measurements: