I am making a remote volume control for my TV, as my amplifier only as a physical button. My idea is to control a digital potentiometer with an microcontroller. I have build the circuit shown on the follwing figure:
The potentiometer shown is a MCP42100, controlled with the microcontroller. As it is for stereo, two of the circuits is used.
However, when i use the potentiometer for attenuation the signal, i get a signal like this:
I do not understand why i get something like this, as it is just passive components and a voltage follower.
This is clearly some kind of clipping, so i added some biasing, which works. Even through it works, i do not understand why, or even why it is needed as the only component the biasing is connected to is the potentiometer.
I suspect that this is coursed for the same reason as the other problem.
I start to belive that the potentiometer is at fault, but i dont know how. This is the datasheet i am using for the potentiometer: http://ww1.microchip.com/downloads/en/DeviceDoc/11195c.pdf
Can anyone tell me what i might fail to see?