I'm in the process of searching for a workhorse, multipattern tube mic to fill a sonic hole in my mic cabinet. The "hole" is in the low mids to mostly quality low end. In my search I've been torn between the classic 251, 67 and 47 sound characteristics. The uses will be the full range of male/female vocals, acoustic instruments and room mic. Not asking much right?

From Cathedral Pipes, the Durham Micro Amp Buffer, designed to add up to an additional 25db of clean, transparent gain for all passive microphones.
It uses typical 48v Phantom Power - found on most mic preamps - to add more db to low-output passive mics, which often require ramped-up gain levels to work at their optimum, and that many lower end preamps don't usually have available.