Neumann's U-47 is a post WWII mic produced by Georg Neumann GmBH. I have understood that the first (maybe 200 or so) were actually built in the Neumann Gefell plant before the Berlin plant got on it's feet! Telefunken designed the VF-14 for this mic, I theorize to make a low cost system using a simple power supply and cable. The capsule design was from 1929! There were in the area of 6,000 U-47's made. It became a "benchmark" mic in the early 50's but was expensive at $375. Engineers found out quickly that the sensitivity of the U-47 greatly enhanced the detail of their recordings.
The U-47 is a very popular vocal mic. There were many U-47's (and U-48's) used for the famous Beatle's recordings. George Martin has written that it is his favorite mic. U-47's are pictured in abundance in the Beatle's recording studio photos. Their aggressive sound makes them an excellent choice for lots of "Rock" applications. Drums, guitars amps and brass instruments shine when sitting behind a U-47!