Vintage Tube Warmth

The Sputnik mic’s military-grade 6205M vacuum tube is a diminutive pentode wired as a triode; the output behavior is like that of a perfect current source so it’s tolerant of a wide range of load conditions. The tube operates at high voltages—allowing an enormous dynamic range—but with less heat dissipation than other designs. As a result, you can easily hang this mic upside down or use it upright without having to worry about overheating the capsule.

http://www.m-audio.com/products/en_us/Sputnik-main.html