A Class-D amplifier operates the output transistors as switches instead of as variable resistors, as in more traditional amplifiers. In doing so, nearly all conduction losses in the output power devices are eliminated, leading to a very efficient amplifier. [via]
DIY class-D amplifier – [Link]
If you have ever wanted to plug in a pro-quality microphone and headphone to an iPhone or iPod touch, pay attention and read on. This guide will show you how to make a cable that will allow you to do just that.
iPhone / iPod Touch DIY Microphone – [Link]
Mark Houston writes:
While looking through the local (Jaycar) electronics store catalogue I came across a Magnetic Cartridge Preamp Kit (Cat. No. KC5433). It uses two LM833 Operational Amplifiers (op-amps) and cost $AU39.95. Naturally, the op-amps can be upgraded with higher performance versions.
DIY Moving Magnet Phono Preamplifier Kit - [Link]
The author wanted to make a device that plays back digital audio, without the use of any programming or a microcontroller or a computer. In other words, the most basic rompler, as a hardware-only device. This is an example of a drum machine.
Drum Machine – [Link]
This is a DIY Headphone amplifier based on OPA2134 op-amp by Texas Instruments.
Apart from running headphones crystal clear, another advantage is that it can act as gain enhancer for my gainclone when watching movies from PC.
Cmoy DIY Headphone Amplifier - [Link]
This project is an audio amplifier rated at 100W. An audio amplifier is an electronic amplifier, which it used to amplify low-power audio signals (20 hertz to 20,000 hertz) to a level that suitable for driving loudspeakers. This amplifier uses the TDA7294 IC from SGS-Thomson which it’s a 100 watt operational amplifier. Check construction details on the link below.
100W Audio Amplifier - [Link]
Aurora is a USB powered multichannel mixer in a typical dj form factor. The device features two linear channel faders, a single a/b crossfader and eight backlit buttons. Twenty four backlit knobs allow you to control effects.
Auroramixer – [Link]
This project shows how to build a parabolic microphone.
Employing any curved reflector and a microphone will greatly enhance the long distance performance over using the microphone alone. Although the reflector used in this particular project was not truly parabolic, it worked very well.
Parabolic Microphone – [Link]
This project is an amplifier designed to drive an 8 ohm speaker or phones to an extremely loud level at small input signal down to 700uV RMS. Although designed to be used with the parabolic microphone also listed on this site, this amplifier is also very well suited for use with any Crystal Set or other low signal output device.
Very High Gain Audio Amplifier – [Link]
This project is a LED lighting system that is able to pulse with the music bit. It is based on Arduino and a PC for signal processing. The audio output is fed to the PC and a script is making the process and calculates the light levels which then are send to Arduino. Arduino is controlling the LEDs via a control board. The system has four LED modules that each have two 4-channel LEDs (red, green, blue, white), this means that is required 32 PWM signals to control all the LEDs. To achieve that the author used 2x TLC5940 16-channel PWM chips. These ICs act like cascading shift registers. Check details on the link below. [via]
Audio controlled LED party lights - [Link]