Tube preamp recommendation ...

With regard to the Dodd buffer, note that it is a passive which can be highly system dependent. Very transparent, but a passive can also have diminished dynamics, drive and oomph. This is what I found with the Dodd in my system, though in other respects it was excellent. If I were to go passive, it is likely what I would choose. But for me, a quality active pre wins out. You do need to spend to get the level of detail that a passive gives, but I find it worth it.

Bob,

It is passive in that it does not offer any voltage gain. Only volume control. In the case of passive buffers (of which the Dodd tube buffer and the FirstWatt B1 are the two best known) will also affect input and output impedances as well as providing no-gain volume control. For non-buffer passive preamps, sometimes impedance mismatches are responsible for less than ideal sound (particularly if a source has a high output impedance).

Particularly with digital sources, which tend to have 2V output signals, the idea is that no additional voltage gain is necessary. For phono outputs, often the signals are much smaller, so make an active pre necessary for certain sound levels.

But in my experience with the Dodd, while it was an excellent preamp, it still did not entirely overcome the lack of dynamics and oomph that I tend to associate with passives I have tried out in my system.

Hi Bob,

Yes, Dodd has both active preamps and the Tube Buffer, which is passive. I'd love to hear the active Dodd someday. But I love on my Musical Fidelity kW preamp, and don't see it going anywhere anytime soon. It has slayed much competition (as always, in my system). I may not have recognized the areas in which the Dodd Buffer came up short if not for having this preamp to compare it to. The kW is also what convinced me of the importance of a preamp for a system's overall sound.