Large diaphragm tube condenser microphone with selectable polar pattern for lead vocals, choir, and stringed orchestral instruments. Handmade at the UA Custom Shop in Santa Cruz, CA

The UA Bock 251 is a large-diaphragm, multi-pattern tube condenser microphone built with high-quality through-hole components and timeless UA design for the professional engineer and recording artist. 

The UA Bock 251 is a high quality variable directivity studio condenser microphone utilizing vacuum tube electronics. Modeled after the AKG designed and manufactured classic ela M251 (90% of which were branded “Telefunken”), originally built in the 1950’s, this mic takes that platform and expands the electronics bandwidth. It utilizes its own proprietary cable and power supply. The microphone’s audio output is standard male XLR3, with positive excitation of the diaphragm at the front of the mic resulting in a positive voltage at the output XLR’s pin 2. Audio output is fully transformer balanced.

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 To Last a Lifetime

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.

UA Bock 251 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

Included Accessories

• Shockmount
• Power supply
• 20’ cable w/ Tuchel connectors
• Signature wooden box
• Suitcase