Grottyash:I'm a bit lost. Don't attenuators decrease output just like turning down the volume? My Naim has a passive preamp and that's meant to be one of the best types there is - why would I need an attenuator when I can just reduce the volume?
Think of it like a car steering wheel that travels twice as far, but turns the wheels just the same amount. It's just greater control.
I did notice a slightly more brittle top end to the setup I used with the attenuators, though whether that was down to them or the preamp/power amp being at a different volume, I cannot say. Sonically I have not given them much attention, I will test them properly at some point though.
It's also good for digital volume controls, as each step makes less of a difference, again, greater control. Sometimes you get that bit just between perfect and too loud etc...