Golden Age GA-47 MKII Tube Condenser Microphone

The Neumann U47 was produced between 1949 and 1965 meaning that the vintage original units are now very old and their performance does differ considerably depending on their condition. The different clones all have their specific sound character too. So, it's not easy to say which sound is "the right one." As always, it's ultimately a matter of taste. The Golden Age Premier GA-47 MKII is the result of a lot of hard work and real-world testing with refinements from the original. The end result is a microphone with a very sweet character that should appeal to a great number of users and a microphone that can be used for the most demanding recording tasks. It has proven itself to be a great all-rounder, this is not a "vocal-only" microphone.

The GA-47 MKII is not a product that is built in huge quantities on a big assembly line. It is a product that is built by hand, fifty units at a time in a small workshop by a skilled and dedicated staff. It uses very high-quality components all the way to achieve the goal of offering classic U47 qualities.

Mic body and grille


The mic body is made of brass, the grille is made of iron. The grille, which is a critical component affecting the sound character, is similar to the one in the U47.


Capsule 


The capsule for the GA-47 MKII is designed to provide the requirements of modern-day recordings by mixing the character between a vintage K47 capsule and the one from a K67-style capsule with a wide frequency response and high sensitivity. The result is a truly great sound. Being a dual-sided one, it provides the GA-47 with both cardioid and omni polar patterns. In order to get a good consistency between units, for each production run of 50 GA-47 units, approximately 200 capsules are evaluated in order to find 50 with specifications that lie within the tight tolerances.

• Backplate material: brass
• Capsule diameter: 35mm
• Membrane diameter: 27mm
• Membrane material:6 micron gold-coated mylar

The capsule is mounted in a special way to minimize the effect from physical vibrations. The sensitivity of the front and back side of the capsule do not differ more than 0.3 dB. The sensitivity between different capsules do not differ more than 0.5 dB.
The tight manufacturing tolerance will lead to a very good consistency between different GA-47 MKII units.

Tube

The GA-47 MKII uses a selected NOS Telefunken EF-800 series super low noise pentode tube connected in triode mode in order to decrease distortion and noise. This tube is modern glass derivative of the VF14M used in the vintage U47.

Output transformer

The GA-47 MKII transformer is especially designed with a 6.5:1 dual bobbin transformer by a reputed transformer factory. It is a replica of the BV8 transformer used in the vintage U47. It uses a high quality core material.

Capacitors and resistors

The coupling capacitor is made in United Kingdom, the brand is Ciarit, the same type used in the famous and very expensive B&W Nautilus loudspeaker. It is an axial capacitor made from MKP material with copper pins. It has a delicate, full sound and a wide frequency response.

Other used capacitors are MIAL polystyrene film capacitors with very low loss. The resistors are ALLEN BRADLEY carbon film resistors made in the USA with vintage and warm sound.

Mic interior

The electronic circuit is built with point-to point wiring on an expensive Rogers circuit board. Teflon insulated, silver-plated copper wire is used for the internal connections.

Power supply transformer and electrolytic capacitors

The vintage style power supply PSU uses a high power R-style transformer with a low noise level and a minimal stray field. The electrolytic capacitors are of a high quality audio style type.


A simple but effective circuit uses dual-stage filtering for the filament voltage. The high voltage is precisely filtered and stabilized using an ON semiconductor zener diode.

Mic cable

The cable is specially produced using 99,99% pure oxygen-free copper, Teflon insulation, tin foil and 98% kitmesh, ie with a very high braided density of the cable shield. It has a very open and smooth sound. The connectors are gold-plated.

Mic and PSU circuit in relation to the original mics

The polar pattern switch is located on the power supply allowing for easy sound comparisons. The circuit used in the GA-47 MKII is similar to the U47 but the component values has been adjusted to fit the EF-800 tube. The circuit used for the power supply is also similar except for adding a zener diode to assure the voltage and current stable. The connectors are gold plated. All three connectors are placed on one side to facilitate handling and placement.

FEATURES:

• High-end, no compromise components and build quality
• Handmade in small series, 50 units at a time, in a boutique-style microphone workshop
• Capsules selected with very tight tolerances
• New Old Stock Telefunken EF-800 tube selected for low noise
• Point-to point wiring, using an expensive Rogers circuit board
• All soldering points made with Mudorf Msolder Supreme Silver Gold solder
• Solid wood microphone box, sturdy metal flight case