This classic re-creation of the BV-12 transformer is handmade by BeesNeez in Australia. The BV-12, when initially created, was something new and not previously attempted in a microphone transformer. The thing that made this transformer so special was the addition of a low impedance tertiary winding. The addition of this winding made it possible for the designer/manufacturer using this transformer to manipulate any selected frequency in an accumulative or subtractive manner, giving excellent manipulation to the output frequency of the microphone. This type of manipulation was previously, and in most cases even today still is, usually accomplished with capacitors and resistors. The downside of this is a lack of control and unnatural realisation of sound. Our BV-12 is the answer if you are looking for a natural sounding manipulatable output transformer, such as is used in the U67 microphone.