Passive Preamp - What makes it work?

Types of passives should at least be mentioned. There's a transformer type I know zilch about, and three resistive types: (1) potentiometers, (2) series stepped attenuators, and (3) ladder stepped attenuators. Almost everyone would agree that (3) is much superior to (2): I've built both with identical resistors and comparable rotary switches, and the difference is easily heard. Some very costly pots may be competitive with (3), but most are clearly not, IMHO. Whether passive or active is better is an unending dispute, but everyone would agree that it depends heavily on the system, in several ways, and that passives are trickier to deal with. In my opinion, they're well worth it, but others will disagree. It's a much-discussed topic in this Forum: maybe you could look up those discussions.

I tried the Creek between an Odyssey Stratos and MSB Nelson dac, shortest possible IC's ( 1.5ft) and hated it. The soundstage became very flat, entirely 2d. Bass and trebble extension was outstanding, imaging was just ok, vocals where hollow and lost presence, overall just didn't sound "right," was only a stereophile class "C" component for a reason. For the cash it can't be beat, but there are many better preamps out there for not much more on the used market. Still, you must try it for yourself in your own system to see what you like. I would suggest trying the Adcom 750 pre as a good alternative that has an active and passive section, and can be had for around $600-700 used.

The FT Audio LW-1 is an excellent passive preamp. I'm using it with a Pass Aleph 30 amp and Kimber Silver Streak ICs. The sound is alive and the soundstage is 3 dimensional. Awesome clarity and warm sound. With passives, the right combination can really swing. Paul Lam of FT Audio recommends Kimber cables (the Select KS-1020 or at least the Silver Streak) as these are highly transparent and clean. This preamp is $500 new (you hardly ever see them new, a real testament to their quality). Both my sources have enough output to drive this syetm easily plus my speakers are easy to drive. The LW-1 has a 30 day trial period and Paul will help you understand if it is a good match for your system. The Placettes are also highly regarded.