In development for 18 months, the newest model in the acclaimed R-F-T line was designed by the company's in-house engineering team, with outside consultation from some of the world's top amplifier designers. The microphone is based around a unique circuit that features a New Old Stock (NOS) TELEFUNKEN vacuum tube, custom audio transformer and a fixed cardioid large diaphragm capsule. Sonically, the microphone carries similar characteristics found in its R-F-T line counterparts the AR-51 and the AK-47 MkII.

Featuring a custom antique copper finish, the CU-29 Copperhead has a silky, open top end, smooth midrange, and a detailed low end. The amplifier design and frequency response are tailored for vocals, however the microphone works exceptionally well on many signal sources including acoustic guitars, amps and percussion.