75th Anniversary UM75 Microphone from Gefell

In recognition of the 75th anniversary of Georg Neumann, Microtech Gefell has launched the UM75 Vintage, a very special limited edition tube microphone to celebrate the 75-year history of Gefell and honour their founding father and the inventor behind the condenser microphone and the famous Gefell M7 capsule, Mr. Georg Neumann.

Scientist Georg Neumann founded the Georg Neumann & Co on November 23rd, 1928 in Berlin, Germany. His management team included Mr. Kuehnast who was responsible for production and product development and Mr. Drechsler who managed administration.

This 1st commercially successful microphone was the CMV-3 designed by Mr. Neumann. The CMV-3 is known as the 'Neumann Bottle' and it would feature a large 30cm high tubular body with a capsule mounted on top like a lollypop. Inside, it boasted the 1st generation M7 capsule. The M7 capsule was made with two closely spaced charged gold evaporated PVC membranes. A tube impedance matching and signal amplifier was employed to drive the signal. Until this time, microphones employed carbon and ribbon transducers. Mr. Neumann's M7 featured a significant improvement in frequency response and dynamic handling, taking center stage during the 1936 Olympics as the primary broadcast microphone.

In 1943 during the 2nd World War, the Berlin factory was destroyed, forcing the company to relocate to the safety of the countryside to the small town of Gefell. The original location was a beautiful 'turn of the century' brick textile factory. After the war, Mr. Neumann was asked by the French government to relocate to Paris where the scientist would soon develop the nickel accumulator, which would eventually turn into the NiCad battery. Although Mr. Neumann lived in Paris he made frequent visits to the factory where we worked with Mr. Kuehnast to bring new ideas to reality.

In 1947, the company moved away from the early 'bottle-neck' design and introduced what would become the first 'modern' microphone, the legendary U47. This microphone employed the M7 capsule. The M7 featured a newly developed Bakelite pedestal that would diffract unwanted body reflections away from the sensitive capsule. This revolutionary microphone design proved to be an instant hit with engineers in that it was both smaller and easier to use than the earlier counterparts. The large 1" diaphragm provided a balance between sensitivity and natural response, making it a favorite for recording and the post war demand for LPs and what would one day become home entertainment systems.

By the 1950s, Neumann had two factories. The Berlin facility was building all kinds of broadcast equipment while the Gefell factory was primarily involved with microphones. In 1957, along with the launch of the stereo LP, the UM57 would set yet another milestone with the introduction of the worlds 1st multi-pattern microphone. This too utilized the M7 capsule but included a plate voltage control switch that would vary the voltage on the back plate to create cardioid, figure-8 and omni-directional polar characteristics.

In 1958, chief engineer Mr. Kuehnast retired, leaving the company in the hands of his protege and son. Today Mr. Jochem Kuehnast is the President and owner of Microtech-Gefell with Mr. Christian Drechsler.

In 1961, with the heightening of the cold war between the communist East and the capitalist West, the inevitable occurred and within days, the East was cut off from the western world. With the erection of the 'Iron Curtain', the Neumann-Gefell factory found itself on the eastern side and in 1962, became closed to all contact with its sister company. This made it impossible for materials to flow from one company to the other, forcing both companies to find new sources for raw materials. Up until this time, due to the difficult process of manufacturing PVC, M7 capsules were constructed in Gefell. This forced the Berlin factory to change the way it made the microphone capsules and spawned the use of newly developed plastics such as polyethylene, which today is commonly sold under brands such as Hostaphan and Mylar.

It would be 30 years later that the Neumann story would take yet another turn. In 1989, the Berlin wall would come down, and due to the pressures from off-shore manufacturers and the digital era and the omni-present CD, disc cutting equipment such as produced by the Neumann-Berlin company would eventually over-stretch the company. A few years later, the Sennheiser Corporation would buy the Neumann assets and Neumann brand name from the now controlling bank and eventually shut the Berlin factory down for good.

But with the fall of the Wall, savvy engineers soon began searching out vintage microphones and discovered that the Neumann-Gefell factory was in fact still operating and still being managed by the same families as before. The surprise was that while the West was using Bruel & Kjaer (B&K) microphones for their test and measurement needs, the Gefell factory had also evolved producing test & measurement equipment for the Russian aerospace industry and military. Today, Gefell test and measurement microphones are employed at famed automaker BMW and at Boeing rival, Aerobus.

By 1992, with the reunification of Germany, ownership was given back to the Neumann heirs and to the families of the original Neumann management team of Mr. Kuehnast and Mr. Drechsler.

This same period opened the door to acquiring new parts and technologies that were developed in the west which helped spawn new microphones and the possibility to re-ignite sales. This led to the refinement of the UM92.1S tube microphone, a quieter version of the original UM57 that would be better suited to meet the demand of today's more demanding recording and broadcast technology. The heart of the UM92.1S is the amazing M7 capsule and this is still made by hand following the recipe originally outlined by Georg Neumann 75 years ago.

To commemorate this amazing history, Gefell announced the limited production UM75 Tube microphone, a remake of the legendary Neumann-Gefell UM57. The Gefell UM75 follows this same tradition in that it is a large diaphragm tube microphone that combines the ubiquitous M7 capsule and the same EF86 tube that was used in the U67. This is combined with the UM92.1S electronics and a custom, digitally controlled Swiss wound, high-output transformer. The combination is a microphone that captures the true essence of the original vintage Neumann-Gefell microphones in a quieter more consistent offering.

A multi-pattern switch on the power supply will offer choice between omni-directional, cardioid, and figure-8 operation. The Gefell UM75 will come complete with power supply, multi-conductor Tuchel cable, full basket elastic suspension, wind screen and storage case and will be finished in a beautiful antique hammer-tone finish with nickel grill and base.

In honor of Gefell's 75-year history, only 75 of these commemorative UM75 models will be produced, each of which will be individually serialized. Interested parties should contact their local Gefell dealer to place their order.