But seriously, unless there's a really good reason to use a contact mic (e.g. you're standing right in front of a speaker), you're usually much better off with a condenser mic, whether stand-mounted or clamp-on.
As a violin player myself, I completely agree. While I've never used one myself, a few people here have recommended ribbon mics as well. For recording, I don't know why anyone would want a contact mic unless they are looking specifically looking for that 'piezo' type of sound.
For live settings, condensers work, but if you need any kind of volume to get over drums, guitars, bass, etc, they aren't a good idea. I know of a few fiddlers who use clip on mics like the DPA and Audio Technica...but if any real gain is needed, then feedback becomes an issue. Also, if you tend to talk, clear your throat, breath heavy, the clip on mic will pick up every bit of it. Contact mics(piezo pickups) are generally the best solution for violins in a live band setting. Avoid anything that sticks on, clamps on, or friction fits to the body or bridge. I've tried several and they just don't sound very good, buzzy, suffer from low output, prone to body thumps, and will make your life miserable in the long run.
The best (live) solution I have found is getting a bridge with the pickup permanently affixed, such as, LR Baggs, Schatten, or Yamaha VNP-1. These are a standard bridge blank when new and need to be cut and fitted to the instrument. Extra luthier cost if you don't know how to do it yourself, but well worth it. The temporary/ removable pickups like Barcus Berry and Fishman are not worth it....avoid. I highly recommend an acoustic preamp for any piezo pickup. The piezos typically need a little boost and suffer from an impedance mismatch. The preamp will remedy this, plus a little bit of EQ/tone control helps. Of course, electric violins are yet another option. I have done several recordings with my solid body electric fiddles, but if I'm looking for a pure, natural, acoustic sounding violin....then a traditional recording mic and an regular ol' fiddle is the way to go!
