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CU-29 Copperhead

Developed around the stellar NOS (New Old Stock) 6AK5W vacuum tube, the CU-29 Copperhead was created to provide a versatile and sonically balanced tube microphone. Coupled with a Lundahl LL1935 output transformer, the CU-29 is a large diaphragm fixed cardioid workhorse, accurately recreating practically any sound source with supreme fidelity. Being a cardioid only microphone, the R-F-T CU-29 Copperhead employs a single-membrane version of the TK67 large diaphragm capsule used in the AK-47 MkII microphone, which undergoes rigorous testing in our laboratory prior to installation.

Sonic Characteristic

Sonically, the CU-29 Copperhead is a remarkably hi-fidelity microphone that provides a warm, clear low end complemented by a smooth, detailed high end. The CU-29 Copperhead is an excellent multi-purpose microphone that sounds great on drums, electric guitar, vocals, bass, piano and a countless number of other applications. The clarity and detail are unsurpassed by any other microphones near its surprisingly low price range.

Circuit Design

The CU-29 Copperhead was developed from the ground up in our South Windsor, Connecticut facility by TELEFUNKEN Elektroakustik’s in-house design team, along with the aid of some of the industry's most knowledgeable and respected consultants. Specific attention was given to circuit board layout, with countless revisions done to optimize current flow and directness of traces. Each component was experimented with and individually selected for the best sonic and electronic qualities. Extra consideration was put on keeping high impedance lines as short as possible to maximize efficiency and minimize unwanted noise. Lastly, a wide array of output transformers was experimented with to provide the most open and sonically pleasing response.


The CU-29’s steel headgrille mesh and brass base ring are finished in an antique brushed copper plating, giving the microphone a unique look and vibe. The aluminum body tube is finished in a black protective hard coat and is engraved with the microphone model name and serial number. A copper plated TELEFUNKEN diamond logo badge is featured on the front of the microphone. The power supply is also finished in a black protective coating.


Each CU-29 microphone comes complete with M 900 power supply, M 800 25’ tube microphone cable, M700 elastic shockmount and wooden microphone box.

Included Accessories

Additional Accessories

Technical Specifications


Pressure Gradient Condenser


TK67S - 25.4 mm Center Terminated Diaphragm

Tube Type

NOS 5654W


Lundahl LL1935

Polar Pattern


Frequency Range

20 Hz - 20 kHz, ± 2 dB


19.5 mV/Pa ± 1 dB

THD at 1kHZ at 1Pa (Amplifier)

< 0.3%

Output Impedance

200 Ω

Maximum SPL (for 1% THD)

130 dB

S/N Ratio

87 dBA

Self Noise (Amplifier)



200 mm L x 46 mm Dia


640 g

Current Draw from Mains

50 mA

Power Supply

M 900 - 7 Pin Female XLR Input, 3 Pin Male XLR Output


M 800 - 25 ft Cable, 7 Pin Male & Female XLR's

Wooden Box


Flight Case

HC00 - Hard Shell Protective Case (not included), FC10S for Stereo Set

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