Manley sells plenty of tubes, some of them new (and if they're good enough for Manley...): http://www.tubesrule.com/category_s/57.htmPhil O wrote:The real problem I see with vintage mics is vacuum tubes. NOS tubes are becoming scarce and the few that are being manufactured now are crap as far as I can tell.
IMO, it would be a mistake to think of "tube-ness" as something which can be added like a sauce. Pro audio designs, intended to be linear and clean, are not the same as overdriven guitar amps. From Manley's site, referring to classic gear (tube and solid-state alike): "These classic products were not designed to colour the signal or add distortion - quite the opposite." If you're intentionally overdriving them (like driving mic preamps for distortion) that's a different thing, of course.Phil O wrote: I think there are some FET mics out there that sound great and I've decided not to invest in anything with tubes. If Slate is getting the vintage tube sound without using actual tubes, I say, "Bravo!"
I'm not an EE, but my understanding is that for the purposes of pro audio design, the most important characteristic of tube circuits is simplicity: a minimalist approach which requires fewer parts and less negative feedback. THD characteristics may also be different between solid-state and tube designs. So, while tubes may "add" something to the signal, their sound could also be characterized as the *absence* of artifacts from typical solid-state designs. This isn't to say that solid-state is bad - just that it's different.
If you start with signal from a solid-state mic, to really make it sound like a tube mic you'd first need to *remove* the solid-state characteristics. Since those characteristics are added harmonics and the effects of greater negative feedback, I'm not sure how you'd do that. You'd certainly want to start with a very clean & neutral solid-state design.
For more very pro-tube insights on the technical aspects of tubes in pro audio, see http://mail.manley.com/tube_talk.php and http://mail.manley.com/mantra.php
None of this is to say that mic modeling isn't useful in practice. I'm sure that people will make great music with it.