The problem you have with a passive control is the cd player (Cal Audio Sigma). It has a very high output impedence of 2K (not 2) or 2000 ohms. Because it is a tubed unit, the output impedence is very high and presents a difficult load to the passive. You need to have at least a 10X difference between the two. So a cd player with output imp of 50ohms would match well with a passive showing a 500ohm input imp. I know from experience you will have restricted dynamics, harsh transients, and freq loss unless you change your source with any passive control. Your amp's input imp and sens. look good to go though. Good luck.
Passive Preamp Problem
I am looking to find a passive preamp to replace my nakamichi ca-7a. But I read somewhere that you need to match your components' correctly for a passive preamp to have good results. But I don't know how to do that. My DAC is a Cal Audio Sigma with 2vrms output with 2ohm output impedance. And my amp is an Aragon 8002 with 120mB for 1watt output input sensitivity and 22k ohms input impedance. I am not sure what all these figures mean. I hope someone here can help me figure it out whether a passive will sound good with my gear. I am contemplating on getting the Creek obh-12.