Tag «Audio Control»

Telephone Circuit: Music On Hold

Waiting a call hold can be boring if there is only silence on the line. It’s a good thing to present an “easy music”  in call hold, make a long waiting time feels much shorter. This simple circuit (consists of diodes, SCR, and some passive components) allows to place the caller on hold in one …

Voltage-Controlled Attenuator (Volume Control) Using FET

Using the circuit shown in the schematic diagram below, we can control the low-level audio signals with ±3V variable DC voltage. This attenuator circuit uses a field effect transistor (FET) to shunt the signal to ground. The R2 is used to control the output level (the attenuation level), but you can use other source of …

Phase Selector (Flipper/Inverter)

Using circuit shown below, we can invert or amplify without inversion by flipping a switch. The voltage gain is depending on the switch position. It could be either +1 or -1. The variation of the circuit comes in two version, A and B. I personally prefer B version, since there is no moment when the …

TDA1524A Voltage Controlled Tone and Volume Control

The device below is built as an active stereo-tone/volume control for TV receivers, car radios and mains-fed equipment. The device below has function for bass and treble control, volume control with built-in contour (can be switched off) and balance. We can control all these function using dc voltages or by single linear potentiometers. This device …

TEA6320 Multichannel Audio Selector and Volume Control

High-end audio equipments are normally digitally controlled by a a microprocessor (microcontroller) system. It’s necessary to have  digital interface that provide control for audio signal switching, as well as programming the gain to control the signal volume. TEA6320 comes with the solution for digital control of audio source channel selector and volume control, very useful …

Digitally Controlled Phase Shifter

As shown in a schematic diagram below, this circuit implementation of phase shifter circuit  is well suited to using digital potentiometer  to control the resistive control element of  the phase shifter. The phase at a given frequency is now under control of a digital signal using this circuit which is optimized for phase-shifting over the …