M 147 Tube

Common name: Neumann M 147 Tube

Production Status: In production

The M 147 Tube is a modern large diaphragm tube microphone manufactured by Georg Neumann GmbH since 1998. It is a fixed cardioid polar pattern microphone inspired by the U 47.  The M 147 uses the technology originally developed for the M 149. Its head grille shape is the same as that of the U 47 albeit slightly smaller. This influences the overall sound of the microphone. For details regarding this topic, refer to the U 47 piece written by Stephen Paul. The mesh used in the M 147 Tube microphone is wider than that used in the vintage U 47, as happens for the M 149 and M 150 Tube models.

The M 147 features a K 47  transducer with MCF (Pe/G) diaphragm that replaced the original M 7 capsule with a PVC-made diaphragm in 1959. The amplifier circuit is borrowed from the M 149 Tube and uses an EC-1000 sub-miniature vacuum tube as an impedance converter coupled to a high-precision, ultra-low distortion transformer-less output stage. This solution achieves a better signal-to-noise ratio and allows very long cable runs up to 300 m without sound degradation. This output stage can drive any kind of microphone preamplifier without overloading.

The M 147 Tube microphone has a very low self noise of 12 dB-A and can withstand up to 114 dB of  SPL. However, the circuit is designed to have a very low distortion rise and is then able to accommodate up to 134 dB SPL with only 5% distortion. This is to properly emulate the sensation of strong loudness found in old recordings of the tube analogue era. The microphone can be exclusively powered by a genuine Neumann PSU (N 149 A) and is only available in a nickel finish.

The M 147 Tube won the TEC Award for technical excellence and creativity in 1999.