Question about Potentiometer / Volume control.

Hi, I have a few questions on a simple matter . Most of the amps I've built never used pots for volume control, I used the signal source's volume control ( digital ) for that .
Now using the classic volume control with a pot like this :
Amp-Volume.gif
would this affect the quality of the signal ? or , change the input impedance based on the pot's location ?. Using a buffer before the pot would help ?.

What about this , would this be a better approach ? besides the output being inverted and not being able to have " zero volume ". would this affect the input impedance as well when pot is turned ?.
betterorno.PNG



What is the best approach for this ? Best way to use potentiometer for volume control ?. ( besides using digital volume control ic's )
- Bruno.