Telefunken U48
10 years after the development of the ubiquitous U47, the U48 was released with one variation to the U47; it had “bidirectional” (figure 8) capability. The bidirectional capability can be very useful in more “ambient” recording environments where the engineer recording the sound does not want to hear as much of the room ambience as might be recorded with an omnidirectional or cardioid pick-up pattern.
Sonic Characteristic
According to the book Recording The Beatles, the U48 was one of George Martin’s favorite microphones when actually “recording The Beatles”. Utilizing the same M7 capsule, BV8 output transformer and VF14K vacuum tube as TELEFUNKEN’s historic reissue of the U47, the U48s authoritative mid-range and extended low-end response make the microphone an excellent tool for recording vocals and acoustic instruments, both near and far.
Circuit Design
Since its original development in the late 1950s, the TELEFUNKEN U48 has been the microphone of choice for generations of recording professionals. The original U48 also featured the famous M7 capsule which had been developed in 1928 by Georg Neumann. To this capsule was added an amplifier built from military surplus VF14 tubes (they had been used in field and aircraft radios), and BV8 output transformers. The combination of these components created a sonic quality that was absolutely unheard of in the English speaking world of the mid-1940s when darker sounding, less detailed ribbon microphones were the standard.
Construction
The large, chrome headgrille houses a newly manufactured M7 capsule. Its matte nickel finished body houses a new BV8 output transformer and a newly developed VF14k vacuum tube; a “plug and play” replacement for the rare VF14M tubes found in the original. The classic “TELEFUNKEN” diamond logo proudly adorns the front of the body tube.
Accessories
Each U48 microphone comes complete with M940 power supply, M840 25’ dual-shielded ACX-7 tube microphone cable, M740 elastic shock mount, FC40 locking flight case and WB40 wooden microphone box.
Technical Specifications
- Type: Vacuum Tube Condenser
- Polar Pattern: Cardioid, Figure-8
- Frequency Range: 20 Hz – 20 kHz, ±3 dB
- Power Source: External Power Supply
- Capsule: TELEFUNKEN Elektroakustik M7 – Center Terminated Large Diaphragm
- Tube: TELEFUNKEN Elektroakustik VF14K
- Transformer: TELEFUNKEN Elektroakustik BV8
- Sensitivity: 24.5 mV/Pa, ±1 dB
- THD at 1kHZ at 1Pa (Amplifier): < 0.3%
- Output Impedance: 200 Ω
- Maximum SPL (for 1% THD): 127 dB
- S/N Ratio: 85 dBA
- Self Noise (Amplifier): 9 dBA
- Dimensions: 240 mm L x 60 mm Dia
- Weight: 620 g
- Included Accessories: Tube Mic Cable, Power Supply, Shock Mount, Wooden Box, Flight Case