My headphone amp has a very good ALP RK50 volume control (not stepped). This is one of those "legendary" components. However, this is a very BIG pot and it costs quite a lot. A friend tried to buy one from the US distributor. He was told that the price is $850 each, and the minimum order size is 50 units. Headamp, the maker of my headphone amp, might be willing to sell someone this pot as they keep it in stock for their own products.