The Neumann SM 2 is an interestingly shaped tube condenser microphone that is quite rare and hard to find. Like all Neumann mics, this is too expensive and fragile to be used for anything outside of the recording studio and since it is a tube condenser microphone is does have its own special cable and power supply that come along with it.
While the Neumann SM 2 tube condenser microphone isn't one of my favorite Neumann microphones out there, it still does have a great sound and will work in a variety of situations. I've only had the privilege of using this microphone a handful of times at a studio and it is the only one of these that I have ever seen and have had a hard time finding out too much information about these relics. The one thing that I have found it to sound really great for is acoustic piano. While I only had access to one of these, I would imagine that a pair of these would sound even better on an acoustic piano as this has a really warm and full inherent tone. This isn't all that similar sounding to any other Neumann microphone that I have used, but it does share the same quality detail that we have come to expect from Neumann products. If you can find an SM 2 I would bet that they would be pretty expensive, but they are definitely tough to find and this isn't a mic that you can really seek out. Its more of the time of mic that you get a lucky find with. Either way, it is a very cool sounding microphone and is one that should be tried out if give the chance. Overall, while rare and not one of the Neumann out there, still a very formidable microphone.