4 channel audio mixer circuit using LM381
This 4 channel audio mixer circuit project is based on the lm381 low noise dual preamplifier IC .
For powering this audio mixer circuit electronic project you can use a DC power supply circuit (or a battery ) that will provide an output voltage between 9 and 24 volts .
Each of the two amplifiers of lm381 is completely independent, with individual internal power supply decoupler-regulator, providing 120 dB supply rejection and 60 dB channel separation.
Other outstanding features include high gain (112 dB), large output voltage swing (VCC b 2V) p-p, and wide power bandwidth (75 kHz, 20 Vp-p).
High gain op amp combines up to four individually controlled input signals . The dc power source should be well filtered , and the circuit should be well shielded to prevent hum pickup .
If you require more audio inputs you can add more inputs , by connecting another 1uF capacitor in series with a 500k potentiometer to the network .