UA Bock 251
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Reach Sonic Nirvana
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. Handbuilt 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
Handwired 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.
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
Choose Your Bock Microphone
Bock 187
FET Condenser
Bock 167
Tube Condenser
Bock 251
Tube Condenser
Polar Pattern
Cardioid
Polar Pattern
Continuously variable Omnidirectional through Cardioid and Figure-8
Polar Pattern
Switchable Omnidirectional, Cardioid, and Figure-8
Capsule
1” diameter
Dual symmetrical backplate
Dual diaphragm K67 typeCapsule
1” diameter
Dual symmetrical backplate
Dual diaphragm K67 typeCapsule
1” diameter
Dual asymmetrical backplate
Dual diaphragm CK12 typeTube
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Tube
New Old Stock EF732
Tube
New Old Stock ECC85
Maximum SPL
125 dB SPL, 1% THD
Maximum SPL
118 dB SPL, 1% THD
Maximum SPL
118 dB SPL, 1% THD
Adjustable
ControlsPAD (-10 dB): Off/On
MODE: Fat/Normal
LOCUT: Off/OnAdjustable
ControlsPAD (-10 dB): Off/On
MODE: Fat/Normal
Hi FREQ: Cut 5 kHz, Cut/Boost 10 kHz, FlatAdjustable
ControlsPolar pattern selector
Frequency
Range20 Hz - 16 kHz +/- 2 dB
Frequency
Range10 Hz - 18 kHz +/- 2 dB
Frequency
Range10 Hz - 18 kHz +/- 2 dB
Sensitivity
-42 dB (8 mV) ref 1V at 1 Pa, 1 kHz
Sensitivity
-29 dB (33 mV) ref 1V at 1 Pa, 1 kHz
Sensitivity
-34 dB (19 mV) ref 1V at 1 Pa, 1 kHz
Output
Impedance200 Ohms
Output
Impedance200 Ohms
Output
Impedance150 Ohms
Recommended
Load
Impedance> 2K Ohms
Recommended
Load
Impedance> 2K Ohms
Recommended
Load
Impedance> 1.2K Ohms
Dynamic
Range113dB
Dynamic
Range99 dB
Dynamic
Range100 dB
Signal-to-Noise Ratio
82 dB
Signal-to-Noise Ratio
75 dB
Signal-to-Noise Ratio
76 dB
Power
Phantom Power
48 VDC, 0.5 mA typicalPower
UA Bock 167 PSU true linear, 115V (default) or 230V operation
Power
UA Bock 251 PSU true linear, 115V (default) or 230V operation
Connectors
3-Pin XLRM
Connectors
6-Pin XLR (mic), 3-Pin XLRM (power supply)
Connectors
Tuchel (mic), 3-Pin XLR (power supply)
“I used the UA Bock 251s as overheads and they took a beautiful picture of my drum kit... A stunning recreation of the original 251 mics.”
– Matt Chamberlain (Pearl Jam, David Bowie, Elton John)*The UA Bock 251 product is not affiliated with, sponsored, nor endorsed by any other company. The "251" name is used solely to identify the classic mic design that Universal Audio's product is based on. All other trademarks are property of their respective owners.Customer Reviews
M. Wertz
October 12, 2023
Great low end
Fabulous mic, incredible low end. A welcome addition to Little Cheddar Studios!
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Customer Reviews
UA Bock 251
M. Wertz
Great low end
Fabulous mic, incredible low end. A welcome addition to Little Cheddar Studios!
