The GA-47XT M7 targets users who are looking for the same great sound as in the Golden Age Premier GA-47 MKII but need some added flexibility.
The GA-47XT M7 has a removable capsule head in the same format as the vintage U47, meaning that it´s possible to use vintage heads on the GA-47XT M7 or one of GAP heads on a vintage U47.
It also has 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 M7 version uses an exclusive M7-style capsule that is very expensive to produce. There has also been some modifications made inside the mic to achieve a sound that is very close to a vintage unit in great condition.
GA-47XT M7 build info
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-47XT M7 capsule heads, approximately five 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-47XT M7 units.
The capsules are dual-sided ones, providing the GA-47XT M7 with both Cardioid and Omni polar patterns.
Tube
The GA-47XT M7 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-47XT M7 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 special regulator component.
A ground lift switch is included to help solving mains ground loop noise issues in some environments.
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-47XT M7 mount and a box made of solid wood for the microphone.
Specifications GA-47XT M7
Polar pattern: Cardioid and Omni
Frequency range: 20 Hz - 20 kHz
Sensitivity: 12 mV/Pa
Rated impedance: 200 ohm
Capsule: S47d, 34 mm, M7/K47-style
Maximum SPL: 140 dB
Equivalent Noise Level: 10dB