He's saying it's not the Khozmo. It's coming from your source. Have you tried a different source? I found this link and I hope it may help.
http://www.audioasylum.com/cgi/t.mpl?f=amp&m=115261.
Quote,
"If DC is present at the output of the source component, the K-5xe (in your case the dac/preamp) will pass it on to the amplifier. However, changing the volume control will change the level of DC that is sent to the amplifier. This will be heard as a small "tick" or "pop" through the speaker. Have you ever noticed any ticking or popping sound from the speakers when changing the volume? " There's more at the link.
Ruby.