At the heart of every successful recording studio is a closely guarded vault of high quality microphones. The ability to match a high quality microphone to whatever is being recorded is of critical importance to the recording process. Many vintage microphones now cost tens of thousands of dollars and new production boutique microphones while not as costly as original vintage units in good condition also demand a high premium. With the help of some enterprising people in the DIY community, it is now possible with a little bit of research and determination to build quite a formidable arsenal of clone microphones that faithfully reproduce the original vintage electronic circuits. One staple large diaphragm microphone design is the original Neumann U87. In this post, I will build a clone of the original U87 circuit.