Advanced Audio CM47LE Tube Condenser Microphone (Demo Deal)

The Advanced Audio CM47LE is a full body or long body version of the original U47. The capsule, tube, transformer, and circuitry are based on the traditional specifications of the 1959 U47. The 1959 U47 was fitted with the venerable VF14M tube and K47 capsule with a brass surround with the CM47LE you get the option of modern multi-patterns while retaining the passive cardioid response of the U47 with the flip of a switch!

In passive-cardioid there is 3 dB more output from the capsule and the self-noise is reduced by 3 dB compared to active cardioid. In the "M" switch position, the 9 pattern switch is engaged; active cardioid is in the center and omnidirectional is full counter clockwise while figure-8 is in the full clockwise 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 cardioid/multi-pattern option. This allows for 3 patterns between omni and cardioid and 3 patterns between cardioid and figure-8. The traditional passive, cardioid method used in the original U47 is retained in the C position on the CM47LE

Like the original circuit designs, Advanced Audio use 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 50s 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 GE/JAN 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 6.5:1 ratio. It yields a warm response with a creamy velvet like presence.

The CM47LE uses Advanced's tried-and-true AK47 capsule, the same capsule used in the CM47ve, CM49, CM48fet, CM48T and CM47fet/CE microphones. All Advanced Audio Microphones capsules are hand skinned using 6-micron, gold-sputtered mylar. Each capsule goes through rigorous testing.

Features:

• Pattern Selector: 9-pattern from power supply
• Passive cardioid/multi-pattern option from body
• Circuit type: Single-stage Class A tube, transformer coupled
• Capsule: center-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 GE/JAN 5654W
• Transformer: Full-sized BV8 dual bobbin footprint with 6.5:1 ratio
• Transformer distortion: <0.5% @20 Hz/+10 dBu and <0.05% @50 Hz/+10 dBu
• Max SPL: 138 dB
• Frequency response: 25 Hz - 20 kHz ±3 dB
• Equivalent Noise Level: <13 dB (A-weighted) selected tube
• S/N Ratio: >86 dB (ref 1Pa A-weighted)
• Sensitivity: -32 dBu
• Output impedance <200 Ohms (load impedance <1.2K)
• Output connector: Male XLR, 7-pin gold plated
• Switchable 120 - 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