Highend audiophile attenuators:
http://www.dact.com/html/attenuators.html http://www.dact.com/html/faqs.html
CT2 Balanced Stereo $325.00
US distr. -
http://www.nutshellhifi.com/dact.html
I've had the older unbalanced version, used it for Hi-Fi.
Had to put it in a metal box, solder a couple of cables, spray the box with a nice blue color, add a chicken knob. No big deal.