Telefunken TF39 Copperhead Tube Condenser Microphone Stereo SetTELEFUNKEN Elektroakustik is proud to offer matched stereo sets of the TF39 Copperhead Deluxe microphones. Each system features a custom dual power supply capable of powering both microphones at one time, and a special locking flight case that will carry both sets of microphones, cables, wooden boxes, and the dual power supply. Stereo microphone techniques are often used for recording classical music and large signal sources like orchestra, choirs,