This is 4 way stereo unbalanced distribution amplifier (DA), which can be used to distribute (or split) input audio signal to 4 isolated audio devices.

Distribution amplifier in this article is based on commonly available TL072 and TL074 low noise operational amplifier ICs and 7812/7912 voltage regulator ICs. To drive this system, 12V-0-12V or 15V-0-15V 1000mA center tapped step-down transformer is required. Also note that the operational amplifiers used this circuit can be replaced with identical high quality versions like OPA4134, OPA2134, etc. In our prototype we use TL07x series because of its availability and lower price.

To avoid any interference it is highly advisable to construct this circuit on PCB and also use double core screened wires for all external audio connections.

Project Related Downloads


Schematic, PCB and EAGLE project files of stereo distribution amplifier project.

References


TL072 - Low-Noise JFET-Input Operational Amplifier
TL074 - Low-Noise JFET-Input Operational Amplifier
OPA2134 - High Performance Audio Operational Amplifier
OPA4134 - High Performance Audio Operational Amplifier
L7812 - 3 Terminal 1A Positive Voltage Regulator
L7912 - 3 Terminal 1A Negative Voltage Regulator