Which Passive Preamp --Bent Audio or Placette ?

I have been reading alot about passive preamps lately and the advantages and disadvantages of them.
I have read about resistor based volume controls such as the one on the Placette Passive, and transformer based volume controls such as the one on the Bent Audio NOH.
Has anyone owned or compared the Placette Passive Preamp and the Bent Audio NOH Passive preamp head-to-head?
If so, how do they compare sonically, and what are the sonic advantages and disadvantages in comparison to one another?
How does the passive Pass Labs Aleph, and the passive section of the Adcom GFP-750 compare to the Placette and the Bent Audio?
Thanks in advance!
If you get the Placette, get the ACTIVE version. It is considerably better than the excellent Adcom (I made that exact upgrade myself, once upon a time).
Bent audio. The only way to go. John Chapman is one of the nicest guys one could ever meet.

You can do no wrong with a transformer based volume control. Go Bent Audio, you won't regret it.
Both great passives, the Placett is along the lines your Pass pre-amp..highly detailed in sound. The Bent is more laid-back at the extream upper fqz's..less detailed. Both units have very good mid-range quality, female vocals are truly magic. The Bent's bass reproduction is the better of the two IMO. If it matters, the Placette is single ended and the Bent can be balanced and (or) single ended. Cost of the two units was about the same at the time I had a listen.

I would like to add a Reference Line Preeminence One or Two to your short list. Of the 7 passive pre-amps I have heard, Reference Line is the best. It also betters any active pre-amp I have heard in my system in regards to depth of soundstage and transparancy. Also the dynamics are fast and equal to the best active pre-amps. I have not heard either the Bent or Placette. But a used Reference Line is considerably less in cost.
Sorry to throw in yet another passive xformer-based preamp but I feel that it might be a useful input.
I have heard Antique Sound Labs T1-DT ($400) passive preamp & it's sound was really excellent. We were listening to some single-driver speakers from Carolina Audio & Cain&Cain. The power amps were also ASL, FYI.
The bigger brother to the T1-DT is the T2-DT ($800) & it is said that the sound improves even further. I have not heard the T2-DT.
Placette gets my vote - in fact, I have the passive with three inputs and two outputs. It sounds invisible to me (if that's not contradictory) and owning it has made music more enjoyable. I also find the remote volume control invaluable. I also got a mono switch which is a great option. The guy who owns Placette is great to work with and very knowledgeable. I trust his company which is one reason I bought his unit.
I want to chime in with a vote for the TVC. I have the Mark I version(much better than the Mark II) of the TX-102s in a custom made preamp. I have heard the Placette and the Reference Line Preeminence 1B. Neither of them could come close to the sound of a TVC in my system. I have owned and heard many a preamp over the last 10 years, and this thing is far and away the best I have heard.

I would add another passive to this list: The Sonic Euphoria autoformer, which I recently bought and enjoy. While I have not compared this directly to a true transformer preamp like Bent, a well-designed autoformer is said to preserve bass dynamics a bit better. In any case, many prefer the sound of a 'former passive preamp over a resistor-based one. You can see reviews of the SE unit at www.onsoundandmusic.com (current issue) and also www.6moons.com/audioreviews/eelectric/preamps.html.
[I have no affiliation with Sonic Euphoria.]