U 48

Common name: Neumann U 48

Production Status: Discontinued / Vintage

The U 48 microphone can be considered a U 47 variant available from 1958. Like the U 47, the new microphone offers two switchable polar patterns, cardioid and bidirectional instead of the omnidirectional featured in the U 47. Neumann’s engineer developed the U 48 keeping most of the parts in common with the standard U 47. As a consequence all the accessories are fully compatible with both microphones. All of the U 48’s are “short body” microphones with a nickel finished head grille (for details about U 47 body evolution please refer to the proper description). Externally the two version are recognizable thanks to the different colour used for the pattern logos. The emblems are black on the U 47 and red on the U 48’s. The second difference between the microphones is of technical nature. In the U 48 to obtain the bidirectional polar pattern the three electrodes of the capsule (the two moving diaphragms and the centre standing electrode) need to be polarised at different voltages keeping constant the” voltage jump” between adjacent electrodes. In the U 47 the omnidirectional polar pattern is obtained by connecting the two moving diaphragms with the same voltage. As both microphones have a 105 V DC supply providing 0 V – 52,5 V – 105 V, the original U 47 polarisation (0 V – 60 V) can’t be obtained in the U 48. This voltage polarisation drop in the U 48 result in a sensitivity that is 1.93 dB lower than in the U 47 ( The U 47 cardioid sensitivity is 25 mV/Pa while the U 48 cardioid sensitivity is 20 mV/Pa). As a consequence it is possible to modify and convert a U 48 microphone to U 47 but not the opposite.