There was a question about using the K&K pickup; I play mandolin in a bluegrass band, and I use the one with the pair of small transducers and an endpin jack. I plug into an active DI box, and an XLR cable then goes to the Mic amplifier on the desk. The only problem with this setup is the lack of volume control for solos, and I don't much like footpedals, so I'm experimenting with a Shure Beta57A as an instrument mic in conjunction with the pickup. There doesn't need to be much gain on the mic, which minimises the chance of feedback, and I just move closer to the mic if I need volume over and above the pickup.
The K&K is sweet; fairly natural sounding (for a transducer) and easy to install in a mandolin with a bit of forward thinking and lots of cotton thread to stop things falling inside prematurely. With the mic as well, it's a really good overall sound; we play through a couple of Bose L1 towers, and this seems to match well with this arrangement. The Dobro player and banjo player do much the same thing.
Tim