THE CM47LE IS A FULL BODY OR LONG BODY VERSION OF THE ORIGINAL U47 CIRCA 1959.
THE CAPSULE, TUBE, TRANSFORMER AND CIRCUITRY ARE BASED ON THE TRADITIONAL SPECIFICATIONS OF A 1959 U47
THE 1959 U47 WAS FITTED WITH THE VENERABLE VF14M TUBE &
K47 CAPSULE WITH A BRASS SURROUND
WITH THE CM47LE YOU GET THE OPTION OF MODERN MULTI-PATTERNS WHILE RETAINING THE TRADITIONAL, PASSIVE-CARDIOD RESPONSE OF THE U47 WITH THE FLIP OF A SWITCH!!
THIS IS ACCOMPLISHED WITH A SWITCH ON THE BODY LABELLED:
 M -  "Multi-Pattern"
      C - "Passive-Cardiod"
In Passive-Cardiod there is 3db more output from the capsule and the self-noise is reduced by 3db compared to active cardiod.
 
In the "M" switch position, the 9 pattern switch is engaged; Active CARD is in the centre and OMNI is full counter clock-wise while FIG 8 is in the full clock-wise position from the 9 pattern switch located on the power supply.
 
The CM47LE features a traditional single stage class "A" transformer coupled U47/U48 tube circuit. The military grade 7 pin sub-miniature tube is simple to replace. Also, the clever lads at Advanced Audio added a passive cardiod/multi-pattern option.  This allows for 3 patterns between OMNI and Cardiod and 3 patterns between Cardiod and FIG 8.  The traditional passive, cardiod method used in the original U47 is retained in the C position on the CM47LE
Project studios can have a true classic sounding tube microphone for a very affordable price.  Tested replacement tubes will be $21
  The CM47LE is also designed to work seamlessly in any serious commercial recording studio and with a variety of microphone preamps
 
CIRCUIT:
 
Like the original circuit designs, we are using a 7-pin military grade pentode tube wired as a triode like the U47 and mounted in a ceramic tube socket. The use of modern, high tolerance components with traditional circuity from the 50's results in a very quiet and very reliable classic performing tube microphone with the extra feature of 9-patterns.
The single class "A" tube circuit stage uses a military grade 5654W sub-miniature 7 pin tube.  Great care was take to closely match the plate current and output impedance parameters to that of the original VF14 tube found in vintage U47 & U48 microphones. 
 
The custom wound transformer is designed to match the BV08 from a 1959 U47 that was set to s 6.5:1 ratio. It yields a warm response with a creamy velvet like presence
 
CAPSULE:
 
The CM47LE has a K47 type dual diaphragm/single backplate capsule having a footprint and response similar to one in a 1959 U47.
Advanced Audio Microphones capsules are hand skinned using 6 micron, gold sputtered mylar. Each capsule goes through rigorous testing here in Canada.
 
SPECIFICATIONS:
 
Pattern Selector: 9-pattern from power supply
Passive Cardiod/Multi-pattern option from body
Circuit type: Single stage class "A" tube, transformer coupled
Capsule: centre fed AK47 (true K47 reproduction with brass surround)
Capsule Polarization: 56V and rear diaphragm 0V in passive-cardioid
Tube type: 7-pin socketed military grade selected military grade 5654w
Transformer: Full size BV8 dual bobbin footprint with 6.5:1 ratio.
Transformer Distortion: <.5%@20Hz/+10dBu and <0.05%@50Hz/+10dBu
Max SPL: 138dB
Frequency response: 25Hz-20kHz + or - 3db
Equivalent Noise Level: <13dB (A- weighted) selected tube
S/N Ratio: >86dB (Ref. 1Pa A-weighted)
Sensitivity: -32dBu
Output impedance <200 ohm (load impedance <1.2K)
Output connector: Male XLR, 7-pin gold plated
Switchable 120v-220v power supply
25' Gold plated 7 pin cable
Heavy Duty shock-mount that easily and tightly clips on to the mic
Sturdy travel case