Oomph or pressure?

@charles1dad ,
Are you a manufacturer/designer?
Bob

 I went through a period where I was very interested in passive but ultimately found an active gave me better involvement with the music. I found the passive to lack dynamics and drive in the music basically the same as the complaint in this thread. 
 I do think a passive with the unity gain buffer may be a good compromise as  it's true what atmosphere is saying, there are impedance issues but we do have plenty of game in our systems.

Hi gdnrbob,
I'm not involved in the audio product industry,  just a nappy music lover. I  heard a friend's MP-1 preamp with my 300b SET amplifier and the combination was quite impressive. If I didn't own the superb Coincident Line Stage I could be "very" satisfied with the MP-1.
Charles 

The term “passive” is an unfortunate one since it includes both resistor-based attenuators and magnetics such as transformers and autoformers.  The complaints often leveled against “passives” relate to problems with dynamics and drive, as others have mentioned, but those complaints pertain to resistor-based passives, not magnetics.  At least that has been my experience.

The OP, however, raised similar complaints about his autoformer, something I have not experienced with mine or heard about from other users.  That’s why I questioned whether he may have a problem with inadequate drive from his source.

I don’t think that’s the issue, it does seem like I have to turn the volume up to around 2 or 3 to get it to have that fullness or pressure in the room.