About the GB-251 Tube Microphone
We present our GB-251 tube microphone, based on the classic Telefunken ELA M 251.
This microphone is a recreation of a classic that is sought after worldwide, as it is part of the largest and most renowned studios.
Everything you have in the original model, you will also find in the Greenbox GB-251.
Equipped with a capsule with 3 polarities selectable by a rotary selector located on the microphone's external power supply, the GB-251 provides a full range of pickup.
The three polarities are: Omnidirectional, Cardioid and Figure 8.
The microphone body is made entirely of carbon steel, with stainless steel grills. This set generates excellent isolation for the microphone, providing maximum performance and a very low noise level.
The 7-pin connector is gold-plated, allowing for maximum signal quality and a perfect fit.
The cable that comes with the microphone is of high quality and is 5 meters long.
About the power supply
We optimized the microphone's power supply by inserting a split power transformer, where the windings are isolated from the plate and filament voltages of the valve.
In addition, the power supply circuit has optimized the rectification of the voltage that feeds the filament, with adaptive filters that generate more stability and noise reduction for the microphone.
In the valve grid power supply stage, we also added an adaptive voltage filter that, in turn, generates more stability for the microphone.
The entire microphone power supply is isolated with a 1.8mm carbon steel cabinet, making all components completely isolated from any external factors.
The yellowish cream paint with a vintage tone and texture makes the GB-251 even more attractive, with a breathtaking look!
Included Items
Greenbox GB-251 Microphone, External Microphone Power Supply, 5 meter 7-way Cable, Deluxe Vintage Case.
Specifications:
Microphone Type Vacuum Tube Condenser
Power Source External Power Supply
Polar Patterns Figure 8, Cardioid, Omnidirectional
Frequency Response 20Hz - 20kHz @ +1dB
Capsule CK12 (Edge Terminate Large Diaphragm)
Tube 12AY7
Audio Transformer 14/1 - High Nickel (custom made by Greenbox)
Sensitivity 17 mV/Pa @ 2dB
THD (Total Harmonic Distortion) 0.25% @ 1kHz
Output Impedance 200 Ω
Maximum SPL 132 dB
Equivalent Noise (A-Weighted) 11dBA
Microphone Weight 500 grams
External Power Supply Weight 1.5 kilos
FREQUENCY CHART:
CARDIOID
OMNI FRONT
OMNI BACK
FIGURE 8 FRONT
FIGURE 8 BACK
