Advanced Audio CM47 valve Condenser Microphone

Advanced Audio CM47 valve Condenser Microphone Advanced Audio CM47 valve Condenser Microphone Microphones

The Advanced Audio CM47 is a large dual-diaphragm, multi-pattern, tube condenser microphone inspired by the famous U47.


The Advanced Audio CM47 features our very accurate and smooth AK67 capsule, a 35mm capsule with 6-micron-thick German mylar diaphragms. Its frequency response falls between those of the U47 and U67 vintage tube microphones. The AK67 capsule goes down another ½ octave before rolling out, compared to the K47 capsule. The CM47 also has more “air” or “sizzle” above 10kHz, allowing it to cut more easily through busy mixes without adding EQ.


The circuit is based on the very hifi 6072 tube optimized with a two-stage Class A design.

This circuit provides a much lower output impedance with more headroom than the circuit used in the original U47. The lower output impedance provides a faster damping factor when driving the BV8 type transformer, delivering a better transient response than the original design.

Selected 6072a tubes are some of the quietest tubes made, and are much less susceptible to microphonics than the metal-clad vf14 tubes used in the original U47 tube microphone.

The dual-bobbin output transformer with its hum bucking configuration and our optimized circuit will deliver +20dBu with less than 1% distortion.

The output transformer is driven with a 2.2 ufd metal-film capacitor to take advantage of the transformer’s response down to 10Hz.

Capsule: 1.07” (35mm) Ak67 dual back plate, dual 6-micron skinned mylar capsule Capsule polarization 60v on the backplate.

Pattern: 9 selectable pickup patterns remotely switched from the power supply

Transformer: Dual bobbin BV8 (6.5:1 ratio) output transformer

Tube: Selected 6072a tube Class A dual stage (CCDA)

Frequency response: 20Hz to 20kHz +/–3dB

Noise: <15dB (A-weighted)

Impedance: < 200 ohm (load impedance <1.2K)

Distortion: < 0.5% @128dB

Maximum Output: > +14dBu with less than 1% distortion

Also included: Robust shock mount that threads onto microphone body

Flight case

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2 weeks
@connormidd Just sold one myself. Looking for cash only. Cheers
2 weeks
Any interest in a trade for a tlm 102?