| AUDIO AMP + 3KHz FILTER This circuit is the audio amp section for a complete optical transmitter. The circuit amplifies and filters the voice audio signals from an electrets microphone. The circuit is described in more detail in the receiver section of Dave Johnson's Handbook of Optical Through the Air Communications. (this link is off-site.) |
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 Power Amplifier: Simple Class A Amplifiers |
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. |
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 Watt Amplifier 2: Low distortion amplifier using discrete components |
2 Wire Remote Microphone Amplifier: uses special amplifier module from Op-Amp Labs |
20 Watt Power Amplifier: Designed to be used as car 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. |
25L6 Amp: design without a power transformer |
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 |
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-Watt per channel |
80 Watt Amplifier #2: Uses the LM12 chip |
ALL FET MC Phono Preamp: Phono preamp with54 and 64 dB gain and RIAA accuracy is better than0.2dB, from Borbely Audio |
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 |
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 |
Boost 3.3V to 5V with tiny audio amplifier: EDN - Design Ideas / 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: EDN - Design Ideas / (added 10/03) 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 |
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. |
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 two microphones to1-microph1-input |
Dual Microphones Separate Voice From Noise: EDN-Design Ideas |
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 |
Guitar Amplifier 10 Watt: Old-Style ultra-compact Combo2-inputs-Overdrive-Treble-enhancement |
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. |
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 (added 4/02) |
LM380 Power Audio Amplifier: National Semiconductor Application Notes,04-Nov-1995 |
Low Cost Audio VChas High Performance: EDN-Design Ideas |
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 |
Making a Rugged, Connectorized Microphone From a Panasonic Microphone Capsule: |
Microphone Mixer: Designed for3-dynamic microphones |
Microphone Preamp: Very simple two transistor circuit |
Mike Pads & Other Small Gadgets: Includes Active Direct Box circuit |
Modification of Panasonic Backelectret Capacitor Microphone (WM GOAT DigiKey P9967 ND): This drawing describes the conventional hookup and option where FET is connected as source follower with3 wires to preamp. |
MOSFET Power Amp: DIY high power MOSFET amplifier200 Wrms 8 ohms -350 Wrms4 ohms |
MS 2 Mic Splitter: Send signal from1-microph1-to two mixers, product datasheet with circuit diagram in PDF format |
MS 82P Microphone Splitter With Phantom Power Buss: 8 channel microph1-splitter that can inject phantom power to microphone, product datasheet with circuit diagram in PDF format |
Neve BA283Volt Class a Circuit: The famous Neve Class A recording series modules such as the1066,1073, and1272 all used a similar gain building block like the BA283AV shown here. This circuit consists of two stages of amplification on a single printed circuit board with an input voltage gain stage and a line driver output stage. |
OTP µC controls Boomer amplifier: EDN-Design Ideas /PDF contains multiple circuits - scroll to find this circuit |
Pocket Equalizer for Headphone: many circuit examples |
Portable Microphone Preamplifier: High headroom input circuitry. 9V Battery powered. |
Quadraphonic Amplifier: This is a four channel amplifier ideally suited for use with quadraphonic equipment such as a Sound Blaster Live card. |
Quick & Dirty Audio Amplifiers: For those of you who like to experiment with audio and would like a "quick and dirty" amplifier that frees you from having to figure out the biasing resistors, this article has two for you and they run off 9 Volts too!.1-uses an Op-Amp and the other used a transistor. |
Single Chip 50 Watt / 8 Ohm Power Amplifier: Uses LM3876 Hi-Fi amplifier IC from National Semiconductor |
Small Amplifier Circuit: Uses many amplifier ICs, from few-Watts to200-Watt |
Sony C 37Condenser Microphone: information with circuit diagram |
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 |
Super Capacitor Powers Audio Amp: EDN-Design Ideas / Micro power and low-voltage op amps allow you to build high-performance analog-signal processors that require no batteries or wall transformers, this simple mixer is powered using one large capacitor such as a Supercap or Dynacap for some Time |
Three Transistor Audio Amp 50 Milliwatt: Here is a little audio amplifier similar to what you might find in a small transistor radio. |
Tube Amplifier: The unit is powered directly from the 120 volt AC line, with no power transformers. Filaments are wired in series, with the total adding up to 117 volts (35 + 35 + 35 + 12). The 35W4 forms a half-wave rectifier, which is filtered by a three-stage RC network. The B+ for the output stage plates and screens are taken from the second capacitor, and the B+ for the preamp and phase inverter from the third capacitor in the filter. |
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 Watt Amplifier: Low distortion amplifier using discrete components |
Two Wire Remote Microphone Amplifier: uses special amplifier module from Op-Amp Labs |
Vacuum Tube Microphone Preamp : from January1997 EQ Column, includes phantom power supply (added 4/02) |
Variable Amplifier Impedance: idea of being able to vary the output impedance of a power amplifier |
Voice Over Circuit: Switches automatically from sound source to microph1-when enough sound comes in from microphone. |
Amplifiers: Audio Circuits
