BAT's website (balanced.com) has a description of their research into various types of volume controls that you may find informative. Click on the "resources" tab to get to the "white papers" -- the one you want is titled the "i-series white paper".
I'd like to learn about volume controls
I've been researching preamps (I currently am very happy with an FT Audio LW-1 passive preamp) and I'm very curious about volume control designs. I know there are different types and different quality. Where can I learn about volume control design, or can anyone briefly explain the differences? Thanks.