The Golden Age Project Premier GA-47 Extended

Handwired Large-diaphragm Tube Condenser Microphone

As Close As You Can Get To The Real Thing

The Golden Age Project GA-47 Extended is designed for users who are looking for the same great sound as in the Golden Age Premier GA-47 but need some added flexibility. The GA-47 Extended has a removable capsule head in the same format as the vintage U47, meaning that it is possible to use vintage heads on the GA-47 Extended or one of GAP heads on a vintage U47.

It also features the polar pattern switch on the front of the microphone below the grille and an aviation style cable socket for an even stronger vintage vibe.

The standard capsule head is the GA-47 Extended HV, using a M7/K47-style vintage style capsule (model no. S47d) with a darker tone, giving the GA-47 Extended just about the same sound as our standard GA-47 model. The GA-47 Extended HM modern capsule head using the K67-style capsule (model no. D35d) that features a brighter and more modern tone can also be selected as the standard head. The GA-47 Extended can be delivered with both capsule head at an additional cost.

Microphone body and grille

The microphone 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 Heads

In order to get a good consistency between units, for each production run of GA-47 capsule heads, approximately four times the needed number of capsules are evaluated in order to find capsules with specifications that lie within the tight tolerances.

The sensitivity of the front and back side of the capsules 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 lead to a very good consistency between different GA-47 Extended units.

The capsules are dual-sided ones, providing the GA-47 Extended with both Cardioid and Omni polar patterns.


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

Output Transformer

The GA-47 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 a SOLEN one, made in France. 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 SIEMENS low loss polystyrene film capacitors. The resistors are ALLEN BRADLEY carbon film resistors made in the USA with vintage and warm sound.

Mic Interior and Cabling

The electronic circuit is uses point-to point wiring, only the ground connections uses a 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 quality type.

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

A ground lift switch is included to help solving mains ground loop noise issues in some environments. As an additional feature, there is -10 dB PAD switch on the GA-47 Extended power supply, so that it can be used for recording high SPL instrument such as kick drum.

Mic Cable

The cable is specially produced using 4n 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 GA-47 Extended is delivered in a tweed-style flight case with power supply, cable, shock mount and a box made of solid wood for the microphone.


  • High End, no compromise components and build quality
  • Built in many details according to the vintage U47 including the polar pattern switch below the grille and switchable capsule head
  • -10 dB PAD switch on the power supply for high SPL instrument recordings like kick drum
  • Handmade in small series
  • Capsules selected with very tight tolerances
  • Point-to point wiring with silver-plated copper wire, a printed circuit board is only used for the ground connections
  • All soldering points made with Mudorf Msolder Supreme SilverGold solder (Sn88, 6Cu, 1,8Ag, 9,5Au)
  • Solid wood microphone box, tweed style system flight case
  • Every mic, box and PSU has a badge with the serial number


  • Package Contents: GA-47 Extended mic with one capsule head, power supply, cable, shock mount, solid wood box, and tweed-style flight case
  • Tube or Solid State: Tube
  • Tube Type: NOS Telefunken 800
  • Capsule Type: 34 mm M7/K47-style vintage style capsule
  • Transducer Type: Condenser
  • Polar Pattern: Cardioid, Omni-Directional, Variable-Pattern
  • Number of Microphones: Single Microphone
  • Impedance: 200 ohms
  • Frequency Range: 20 Hz – 20 kHz
  • Input Pad: -10 dB
  • Sensitivity: -38.4 dBV/Pa (12 mV)
  • Max. SPL: 140 dB
  • Analog or Digital: Analog