....which, as a product, actually has nothing to do with this post.
However, the ART Tube MP Studio Mic Preamp HAS a tube (presumed twin-triode) with a power supply, 2 pots with knobs, 4 pushbuttons, a real analog kneedlemeeter, some (presumably two) connectors and an enclosure.
Currently going for $29.99 from Musicians Friends thru end of Feb08.
It might make a good starting point for a DIY effect. One can't buy them there parts for that little $cratch.
I've got the ART Tube MP Project and it is solidly made and performs as advertised. This would probably be worth picking up just to have around, for experimentation if nothing else. It will certainly warm up a vocal recording, and works nicely to clean up the piezo pup in my old Washburn flat top. Great price, too. Thanks for the heads-up on a good buy, Chris!
got one of these little suckers. Interesting device. at the outer limites it has a compressor effect like a compressor stomp box dialled out too far, losing attack.
At more sane levels, it has a musical effect, as noted. warming up a signal without losing fidelity. I find it useful if one of my outputs is adding too much solidstate brittleness, the device tames that.
It is not a overdrive type tube circuit, so dont expect a "boogie in a box." I have a friend who uses it all the time with his modeler. I use it more sporatcially, but nice to have around, especially for recording.
Pretty sure it's a 12AX7 in there. I've had a DualMP for years. Basically two MPs in a rack box. Nothing spectacular, but doesn't suck for mics.
Can get some crunch going on if you push it. It's important to note, though, that pure 12AX7 overdrive is pretty nasty, and not a lot happier than opamp clipping. Really requires the "tone shaping" of the imperfect speakers in imperfect enclosures that we find in guitar amps to be listenable for most people.
We had one of the MPs that had the compressor built in for a while. The preamp sounded okay, but the comp didn't really do what I expected...
My Project model uses a 12AX7A (according to the user manual), and yes, I can get a little crunch out of it, but it isn't really usable. Ashcatlt is right about that. I would expect the Studio model uses the same tube.