I'd have to agree with topspeed on the resolution at low volume with the CA. That's a good observation. I've got mine in an office too, so low to moderate volume listening is it. Speakers are Paradigm Minimons (90dB room/87dB anechoic,which do most manufacturers use?) and 'compatible w/ 8 ohm'.

BTW, a rotary knob doesn't mean 'infinite volume settings'. The knob is just an interface, it can still be adjusting a digital control with big steps. Generally I find steps of 0.5dB invisible to my ear. I don't know but I'm betting the volume control on most modern amps/receivers is operating digitally and not analog.

I've got the 540A in black. Very good looking.

noddin0ff