What is a digitally controlled SPDT switch that passes an analog signal?
One of the simplest types is the CD4053 IC. It does not have buffers on the analog inputs.



It has 3 SPDT analog switches in one package, each with a separate control signal.

It requires a power supply that can span up to 18v.  The signal must be between these supply rails (i.e. less than the positive supply and greater than the negative supply)

This device has been around for more than 40 years but there are many similar variants.