Golden age GA-251 MKII

The Telefunken ELA M 250/251 was manufactured for Telefunken by AKG after Neumann discontinued its OEM production of the Telefunken U-47. The Golden Age Premier GA-251 MKII is inspired by this truly classic microphone.

The GA-251 MKII shares the same design goal as that set for the GA-47: to offer the classic qualities and benefits that a mint condition vintage unit would provide at a low price.

The MKII version has the following improvements:

A new CNC produced base plate in brass.
Improved and more uniform grille
The interior design is neater and more stable thanks to an expensive Rogers PCB with point-to-point wiring, resulting in ever more refined sound quality.
A new metal flight case and a black cardboard box
Microphone body and grille
The body of the microphone is made of brass, the grille is made of iron.
The grille, which is an essential element affecting the sound character, is similar to that of the ELA M 251.

Capsule
The GA-251 MKII uses a 34mm K251 type capsule. Being double-sided, it provides cardioid and omnidirectional polar patterns. In order to achieve good consistency between units, for each production run of 50 GA-251 MKII units, approximately 200 capsules are evaluated to find 50 capsules with specifications that fall within tight tolerances.

The sensitivity of the front and rear sides of the capsule does not differ by more than 0.3 dB. The sensitivity between different capsules does not differ by more than 0.5 dB.

The tight manufacturing tolerance will lead to very good consistency between different GA-251 MKII units.

The capsule is specially designed to complement the electronic circuitry of the GA-251 MKII to achieve a frequency response curve with a nice balance between high, mid and low frequencies. The result is a very smooth sound with warm bass and airy highs, just like the ELA M 251.

Tube
The GA-251 MKII uses an ultra-low noise NOS Phillip 5840W pentode tube connected in triode mode to reduce noise. The tube has the following characteristics:

Balanced sound response
Soft, warm sound character and low noise level
Long lifespan: The GA-251 MKII amplifier features a new proprietary circuit designed around the NOS 5840W tube.
Output transformer
The GA-251 MKII transformer is specially designed with a 10:1 AMI style dual coil transformer. It is made from Permalloy steel sheet from the United States and enameled wire from Germany. It offers wonderful sound character with high resolution and excellent balance between low, mid and high frequency bands.

Capacitors and resistors
The coupling capacitor is manufactured by Solen in France. This is a highly balanced film capacitor made from MKP material with pure oxygen-free copper connections. It has a very delicate and balanced sound.
The capsule capacitor uses NOS Siemens antique grade polystyrene capacitor to reduce losses.

The tube cathode bypass capacitor uses a high-end hifi ELNA OFC Cerafine capacitor from Japan with oxygen-free copper connections featuring a very soft and delicate character, especially for vocals. The other capacitors are low loss polystyrene type.

The resistor used to adjust the capsule voltage is a high quality DALE 1% metal film resistor. The result is a very stable and consistent level of operation leading to better consistency between different GA-251 MKII units.

The plate resistor uses a non-inductive resistor from USA IRC Audio with pure copper connections. The sound level is rich and full-bodied.

Interior of the microphone
The electronic circuit is built with point-to-point wiring, all soldering points are made with Mudorf Msolder Supreme silver gold solder.
All inner wires use pure silver wire and reduce the loss during circuit transmission, it can also ensure the sound quality is transparent.

All components connected to the electrical ground are connected to the ground plane of the printed circuit. All other component connections use point-to-point wiring, resulting in virtually zero loss and crosstalk.

Power transformer and electrolytic capacitors
The vintage-style power supply uses a high-power Type-R transformer with low noise and minimal stray field. A simple but effective circuit uses two-stage filtering for the filament voltage. The high voltage is also precisely filtered and stabilized using an ON semiconductor Zener diode.

The polar pattern switch is placed on the power supply so that the sound engineer can change the polar pattern between cardioid and omnidirectional remotely. A grounding switch will help resolve AC power related noise issues that may appear in some cases

Microphone cable
The cable is specially manufactured from 99.99% pure oxygen-free copper, Teflon insulation, tin foil and 98% kitmesh, i.e. with a density of very high braid of the cable shield. It offers a very open and smooth sound. The micro connector is an aviation-style plug providing solid connections and long life.