This device, connected to the loudspeaker output of an audio amplifier, will indicate the instantaneous output power delivered to the loudspeakers by means of six LEDs illuminating one after another by voltage values increasing little by little, providing the visual impression of a luminous bar or column, increasing and decreasing in height following the increase and decrease of the signals level.
The circuit in reduces noise and ripple by at least 35 dB over the audio range of 100 Hz to 20 kHz. The circuit provides a clean source of 5V power for driving audio circuits in portable applications such as cellular phones and multimedia notebook computers.
In any recording situation, monitoring is critical to make sure you're getting what you want on tape. This is just as true in field recording, but in most cases, one's monitoring options are severely limited--stereo headphone is the only choice.
A transformer is an electrical device that allows an AC input signal (like audio) to produce a related AC output signal without the input and output being physically connected together.
JT-MB-C in Low Noise, High Isolation Line Receiver for Low-Z Sources
This project describes the construction of test equipment for double-blind or ABX testing of source components - preamplifiers, tuners, DACs etc. or even, if that is your particular vice, interconnects.
The ESP Sound Impairment Monitor is a method of determining just how much your amplifier modifies the original signal. The first version is designed to be built into an amplifier circuit, and although quite simple in concept will indicate if any modification is made to the signal by the amp, for any reason at all.
A circuit for a single-channel audio compressor using a JFET to control the gain of a virtual earth amplifier.
It makes use of the ICL8038 signal generator chip, manufactured by Intersil. An improved version, made by Exar corp. is available (XR8038A). It can be used to produce three types of waveforms, sine, square and triangle. The frequency, amplitude and duty cycle can be varied, and selection of waveform is done digitally.