The UA Bock 251 is our flagship large-diaphragm tube condenser mic, giving you the smooth, open tone of the iconic ELAM 251, considered by many to be the greatest vocal mic ever made. Each microphone is handmade in Santa Cruz, California, to the exacting specifications of world‑renowned mic designer David Bock.
Add Handmade Magic to your Studio
The UA Bock 251 is David Bock's loving interpretation of the classic 251 microphones he studied and maintained as chief technical engineer of the world's top recording studios for two decades. Hand-built at UA’s Custom Shop in Santa Cruz, California, the UA Bock 251 mic puts "golden unit" sound at the heart of your recordings.
Rich Tube Mic Sounds, with Updated Sonics
With its German-made CK12 capsule and large output transformer, the UA Bock 251 gives you extended low‑frequency response down to 10 Hz and higher SPL capabilities versus vintage 251 microphones.
Built for a Lifetime of Harmonious Recording
Hand-wired using premium components, each UA Bock 251 is built and tested to David Bock's exacting specifications. With its vintage-inspired case, robust shock mount and accessories, this mic spares no expense to last a lifetime.
Main Features:
- Large-diaphragm tube studio condenser mic, lovingly handmade at the UA Custom Shop in Santa Cruz, California
- Iconic, "golden unit" mic sounds with modern enhancements by David Bock
- Switchable omnidirectional, cardioid, and Figure-8 polar patterns
- German-made CK12 capsule and Cinemag transformer
- Frequency Response: 10 Hz - 18 kHz, ± 2 dB
- Max SPL: 118 dB SPL, 1% THD
- NOS ECC85 tube
- Requires included UA Bock 251 PSU true linear power supply
- Premium vintage-style suitcase
Specifications
Polar Pattern
Switchable Omnidirectional, Cardioid, and Figure-8
Capsule
1” diameter
Dual asymmetrical backplate
Dual diaphragm CK12 type
Tube
New Old Stock ECC85
Maximum SPL
118 dB SPL, 1% THD
Adjustable
Controls
Polar pattern selector
Frequency
Range
10 Hz - 18 kHz +/- 2 dB
Sensitivity
-34 dB (19 mV) ref 1V at 1 Pa, 1 kHz
Output
Impedance
150 Ohms
Recommended
Load
Impedance
> 1.2K Ohms
Dynamic
Range
100 dB
Signal-to-Noise Ratio
76 dB
Power
UA Bock 251 PSU true linear, 115V (default) or 230V operation
Connectors
Tuchel (mic), 3-Pin XLR (power supply)