Neumann SM2 c Stereo Tube Microphone #1037 (Vintage)

Excellent stereo microphone in great shape with original nickel capsules and AC701 tube. Detailed, open top end, with tight rich lows. Nice on overhead, room, piano, strings, guitars, etc.

The Neumann SM2 is essentially a pair of KM56 capsules mounted next to each other. The upper capsule can be rotated over a range of 270 degrees. The PSU has a pair of 9-position rotary switches to select between omni, cardioid, figure eight, and all steps in between.

To use as an X-Y microphone, cardioid is selected for each capsule, and the recording ‘aperture’ is controlled by the angle between the upper and lower capsules against the main axis.

For M-S recording, the capsules are positioned with the pattern for the M-channel set to cardioid and on-axis, while the S-channel is set to figure eight and offset by 90 degrees. The cardioid mic thus picks up the complete sound event exactly like the principal mic for a monaural recording, and all directional information is picked up by the figure eight capsule. The two mic outputs are combined in a matrix to form the sum and difference signals, which become the left and right channels.

History

The Neumann SM2 was the first stereo condenser mic ever produced, and since its creation in 1956 it remains one of the finest stereo microphones ever made. It's essentially a pair of KM56 microphones in one body, using the classic AC701 tube and the special nickel capsule that gives the KM56 its luxurious tone. 

From the original Neumann brochure:

"The Stereo Condenser Microphone SM2 is a top flight studio microphone. It features the outstanding qualities inherent in condenser microphones and their great versatility enables them to be used for solving the most complex recording problems.

The SM2 can be applied to a wide range of recording techniques. Since it contains, effectively, two single microphones in one unit, the SM2 may be used for various special applications. It was developed to stereophonic recordings, in particular for the "intensity system" but they can also be used advantageously, when two microphones of different directional characteristics are required in the same position."