Golden Age Project GA-251 Handmade Large-Diaphragm Tube Condenser Microphone

The microphone body is made of brass to ensure long-lasting durability. The grille, a key component affecting the mic's tonal character, is made of iron.

The capsule for the GA-251 utilizes a 34mm K251-style capsule to ensure the classic qualities of an original Telefunken 251 microphone. Being dual-sided, it provides the GA-251 with both cardioid and omnidirectional polar patterns. For each production run of 50 GA-251 units, approximately 200 capsules are evaluated in order to find 50 capsules with specifications that lie within the tight tolerances defined by Golden Age Premier.

The 34mm-diameter capsule has a brass backplate, while the membrane, made of 6-micron Mylar coated in gold, is 34mm in diameter. The capsule's front and back sensitivity values do not differ more than 0.3 dB. Capsule-to-capsule sensitivity variances do not exceed 0.5 dB. The capsule is specially designed to complement the electronic circuit of the GA-251 and to achieve a frequency response curve with a pleasant balance between the high, middle, and low frequencies, resulting in a smooth sound with warm bottom and airy top end like the ELA M251.

The GA-251 uses a NOS Phillip 5480W super low noise pentode tube connected in triode mode in order to decrease the noise. The tube has the following character:

• Balanced sound response
• Smooth and warm sound character and a low noise level
• Long lifespan

The GA-251 amplifier features a proprietary circuit designed around the NOS 5840W tube.

The GA-251 transformer is specially designed with a 10:1 AMI style dual bobbin transformer. Made from permalloy steel sheet from the USA and enamelled wire from Germany, it offers a wonderful sound character with a high resolution and great balance between the low, middle, and high frequency bands.

Manufactured by Solen from France, the coupling capacitor is a high balanced film capacitor made from MKP material with pure oxygen-free copper connections and features a very delicate and balanced sound.

The capsule capacitor uses a NOS Siemens antique grade polystyrene capacitor to reduce loss.The tube cathode bypass capacitor uses an ELNA OFC Cerafine high end hifi capacitor from Japan with oxygen free copper connections exhibiting a very sweet and delicate character, not the least for vocals.

The other capacitors are of the low loss polystyrene type.

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

The plate resistor uses a non-inductive resistor of the United States IRC audio with pure copper connections. The sound level is rich and full bodied.

The electronic circuit is built mainly with point-to-point wiring and the ground connections are tied together using an insulated soldering. Teflon-insulated, silver-plated copper wire is used for the internal connections. All solder points are made with Mudorf Msolder Supreme SilverGold solder.

The vintage-style power supply uses a high-power, R-style transformer with a low noise level and a minimal stray field.

The electrolytic capacitors are high-quality, audio-style units. A simple and effective circuit uses dual-stage filtering for the filament voltage. The high voltage is precisely filtered and stabilized using an ON Semiconductor zener diode.

The polar pattern switch is placed on the power supply so that the recording engineer can change the polar pattern between Cardioid and Omni remotely.

A ground lift switch will help to solve mains/power-related noise issues that can appear in some cases.

The XLR 7-pin cable is produced using 99.99% pure oxygen-free copper, teflon insulation, tinfoil, and 98% knitmesh with a high braid density. The connectors are gold-plated for enhanced conductivity.