So I have a simple audio selector circuit with one output going straight into a simple opamp for headphone amplification.
For volume control I am using a DS1802 chip and everything is going to be controlled via microcontroller. The switching is done by a basic CD 4052 multiplexer.
Now every piece of the circuit works fine alone and when connected with other pieces (i.e digit pot to amp, mux to amp). The only problem is when connecting the DS1802 and CD4052. There is alot of noise especially as you increase volume. Not just the volume of the noise but the amount of it too. At the highest dB setting you get a large rhythmic popping buzzing type sound.
I can draw up a schematic but its simply connected to each other.
Signal into mux>signal out to high side of digipot>amp connected to wiper>signal out of amp.
I'm not looking for hi-fi here at all, this amount of noise is louder than the actual music though.
For volume control I am using a DS1802 chip and everything is going to be controlled via microcontroller. The switching is done by a basic CD 4052 multiplexer.
Now every piece of the circuit works fine alone and when connected with other pieces (i.e digit pot to amp, mux to amp). The only problem is when connecting the DS1802 and CD4052. There is alot of noise especially as you increase volume. Not just the volume of the noise but the amount of it too. At the highest dB setting you get a large rhythmic popping buzzing type sound.
I can draw up a schematic but its simply connected to each other.
Signal into mux>signal out to high side of digipot>amp connected to wiper>signal out of amp.
I'm not looking for hi-fi here at all, this amount of noise is louder than the actual music though.
Ensure all the analog voltage going to the switching inputs of the 4052 is within the power supply rails of the 4052. Some circuits clamp the analog and digital inputs with schottky diodes to the supplies.
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