Bock Audio

Bock 47

  • Sale
  • Regular price R 83,909.12

Bock Audio is known for its for using modern methods and readily available components to build microphones with a sound akin tothe great microphones of the past. The Bock 47 continues in that mode by using the Power Supply and Amplifier from the flagship 5ZERO7 microphone and combining a custom made k47 type capsule to bring the performance of the original 50's era German tube 47 in an all new Bock 47. Additionally, the Bock 47 is a cardioid only mic, as the original was used nearly exclusively in cardioid. Included comes a remote power supply and professional spider type shock mount as well as a special custom 20ft cable between the mic & power supply.


  • Microphone Type:Tube
  • Mono/Stereo:Mono
  • Polar Pattern:Cardioid
  • Diaphragm Size:1"
  • Frequency Response:10Hz-18kHz (±2 dB)
  • Max SPL:94 dB SPL
  • Output Impedance:200 ohms
  • Sensitivity:26 mV/Pa
  • Self Noise:18dB (A weighted)
  • Power Source:48V phantom power
  • Features:NOS EF814k tube
  • Color:Gray
  • Connector:Multi-pin cable with remote power supply
  • Weight:1 1b. 9.3 oz.

How to use it

The 47s primary use will likely be male or female lead vocals due to its signature proximity effect. The original 47 had proximity effect behavior that was part of its sound and why it defined "big vocals". With up to +12dB of boost at 100Hz when used at 1 inch working distance, the 47 signature was "the sound" of many great artists such as Frank Sinatra. Led Zeppelin 1 used a 47 on nearly every vocal track. Tuesday Night Music Club and Sheryl Crow was a classic application of a 47 for vocals. The key application was then and still is close worked vocals, male or female.

Tube 47's were never really flat even at distance (beyond 18inches) due to its signature head grille sound. Brass instruments were a favorite 47 application (the classic jazz signature of the most famous records from the 1950's) and small ensembles (of nearly any instrumentation) saw the 47 as the "go to" mic. Cello and violin at short distance gain intimacy and acoustic or electric bass will find a perfect warm tone without muffling using the Bock 47. Individual drums or drum kits will have astounding impact with no overt artificial high end found when using some small diaphragm mics. Solo performers who sing while playing acoustic guitars may be recorded with just this one microphone.

What makes it different

For about half what you'd expect to pay for a vintage original, with replacement parts and "new-old-stock" tubes that are readily available,

the Bock 47 enables a range of sounds and tonal characters previously not available through any other means. The Bock 47 embodies all the most important characteristics of the original while offering consistency, reliability and long term serviceability that is a requirement for today.

  • Patterns:   Cardioid
  • Frequency Range:   30Hz to 18kHz, +/-2dB
  • Sensitivity:   19mv/Pa (-34dBm=94dB SPL)
  • Equivalent Noise:   18dB (“A” weighted) 32dB (unweighted)
  • Distortion vs.SPL @1kHz: 112dB = 0.5% THD 118dB = 1% THD129dB = 2% THD [increasing distortion is non-exponential, nearly linear, and primarily 2nd harmonic]


  • Impedance:   200 Ohms true transformer balanced
  • Recommended Load:   1.2k Ohms
  • Dynamic Range (maxSPL-"A"noise):   94dBS/N (94dB-noise): 76dB “A”, 62dB unweighted


  • Capsule size:   1” diameter, dual asymmetrical backplate
  • CK12 Tube type:   New Old Stock EF814k
  • Dimensions:   2.04” dia x 8” oal (52x216mm)
  • Weight:   1lb 9.6oz (1.58lbs) =694g
  • Shipping Weight:   12 lbs
  • Power Supply:   P251 true linear, factory wired 115v or 230v operation