2 Watt Amplifier 
      ECM Mic Preamplifier

     Tone Controls

     Stereo Line Driver

     TDA2030 8 Watt amplifier

     Audio Notch Filte

    6 Input Mixer 


   Hi-Fi Pre-Amplifier 

   Peak Reading Audio Level Meter

   Doorphone Intercom 

   Computer Microphone

   100 Watt Amp Circuit

    3 Band Equalizer

   Voice-Over Circuit

    Quadraphonic Amplifier

    15 Watt Amplifier 

     Audio VU Meter  

      Soft switching Amplifier with Tone Controls

    Audio Level Meter

    Dynamic Microphone Amplifier

    Headphone Amplifier

      Low Voltage Preamplifier

    Class A//A-B 100W Amplifier 

    Vinyl Amplifierd

     Op-Amp Microphone Preamplifier

    Buffer Amplifier 

     The Gem Amplifier 

   150W MP3 Car Amplifier 

    24 Watt Class A Amplifier 

  32 Watt Stereo Amplifier

    200 mW Watt Stereo Amplifier

   2 Watt Amplifier 


  سه سطح براي ميزان صدا
10 Watt Audio Amplifier
10 watt audio power amplifier using discrete transistors (includes PCB layout)
100W Guitar Amplifier
100W RMS Amplifier
110mW emitter follower audio power amplifier
12 dB Amplifier and High Current Line Driver with DC Servo (PDF)
13.5 Watt Power Amplifier using a TL081 opamp and TIP125 / TIP120 power transistors
150W audio amplifier that's cheap to build using TIP142 / TIP147 Darlington power transistors
16 Watt amplifier
20 dB Amplifier and High Current Balanced Line Driver
20 Watt / Channel Stereo Power Amplifier
20 Watt Audio Power Amplifier
20 Watt Class-A Power Amplifier
22 Watt Audio Amplifier
22 Watt Stereo Amplifier using TDA1554
22W Audio Amplifier
25 Watt MOSFET Audio Amplifier using IRF532 / IRF9532 hexfet transistors for output stage
25W MOSFET audio amplifier
2W Audio Amplifier using BD139 and BD140 transistors
300W Subwoofer Power Amplifier
300W Subwoofer Power Amplifier
30W ultra-low distortion audio power amplifier
360W RMS into 8 ohms or 550W RMS into 4 ohm audio power amplifier
4 channel power amplifier with bi-amping and bridging options
4W amplifier
50 Watt Amplifier
50W Amplifier
50W audio amplifier using ICL8063
50W audio power amplifier
8 Watt amplifier
8 watt audio amp
Ampliefied speaker, built for MP3 player but can be used with other headphone only devices (PDF)
Amplified ear for surveillance
Amplifier based on LM4780 including a thermal shutdown feature
Audio Amp Output Power Limiter
Audio amplifier output relay delay
Audio amplifier with squelsh-control
Build a good Audio Buffer Amplifier
Class-A/AB Amplifier delivering 100W into a 4 ohm load
Class-C power amplifier
CMoy pocket headphone amplifier
Compact 50W Integrated Amplifier with Meier Headphone Section
Crest Audio LT Series LT100, LT1500 and LT2000 Schematic Set - class D amplifier (PDF)
Death of Zen (DoZ) - A New Class-A Power Amp
DIY Headphone-Amplifier with Natural Crossfeed
DPA 220 amplifier schematic
DPA 440 amplifier schematic
DPA 880 amplifier schematic
Easy to build DIY 50W amplifier based on ICL8063
El-Cheapo - A Really Simple Power Amplifier
Five Tube Stereo Amplifier
Hammonator Organ to Guitar Amp Conversion (tube amplifier)
H-Bridge Power Amp circuit diagram and SPICE simulation files
HeadBanger Headphone Amp
Headphone amplifier based on 12AX7 tubes
Headphone monitor amp
Headphone practice amplifier
Hi-Fi Headphone Amplifier
High quality exponential VCA
LM380 2.5 watt audio amplifier circuit
Low impedance microphone amplifier
Low Power Audio Amp Experiments
Low power audio amplifier circuit based on LM386
Low power audio amplifier using BC109C along with BD679 and BD680 Darlington pairs
Mini bench amplifier (LM386)
Miniature audio amplifier
Mini-MosFet Audio Amplifier
More Discrete BJT, Low Power AF Amp Experiments
Potpourri of Transistor Audio Amplifier Circuits
Quadraphonic Amplifier based on pair of LM1877 devices
Ruby is an "enhanced" version of the Little Gem battery-powered amplifier (LM386 based design)
Selection of Integrated Circuit Audio Amplifiers
Simple 0 to 24 dB Gain Amplifier and Balanced Line Driver (PDF)
Simple 200W audio amplifier
Simple Class A Amplifier - 10W audio output
Simple class-D amplifier based on 555 pulse width modulator
Single Chip 50 Watt / 8 Ohm Power Amplifier
Single Supply Simple Mosfet Audio Power Amplifier Design
Small audio amplifier based on LM386
Small bench amplifier ideal for testing audio stages in circuits
Soft-Start Circuit For Power Amps
Soft-Start Circuit For Power Amps
Spatial Distortion Reduction Headphone Amp
Speech Amplifier Box
Stereo audio amplifier based on TDA2822M
Super linear Headphone amplifier
Super Simple 3 Watt Audio Power Amplifier based on TDA1015
TDA2030 8 Watt amplifier
Thermo-Fan To Keep Your Amp Cool
Tube amplifier
Two 9v battery-powered amps based on the LM386. Schematic and PCB/perfboard layouts.
Two Transistors Audio Amplifier
Variable Amplifier Impedance
Voice Amplifier