I've always dreamed of owning a Neumann U87 microphone. But at $3000-$4000 a pop it was never an option. Then I discovered that the schematics are freely available to the public, and the parts are all obtainable. I've never attempted to build a microphone before, or any other electronic gadget for that matter, so it was a deep-end dive for me but I was compelled to try it.
And of course, I couldn't build just one. It's gotta be a stereo pair.
I ordered the parts from various sources, making sure to select high quality parts and not to go the cheap route. The capsules are a matched pair of genuine K87 capsules, the body and shock mount from a maker in SF, output transformers by CineMag were made to order, the PCBs were made in Canada, and the rest of the components and switches came from Mouser.
The only component missing was the JFET, which proved hard to find. I searched all of the local shops I could find in Osaka, and nobody carried the particular JFET the mics needed. I found one eBay shop in China, but it turned out to be a fake. Eventually, I found a UK-based vendor who carried the JFETs I needed, so I ordered them and they worked great! After biasing the JFETs I was finally able to complete the microphones.
When I first tested the mics I was worried because the output was extremely low, so I thought I had done something wrong. But after letting them warm up for a while and feeding them with music from my speakers to get the capsules moving, they started outputting more.
I took the mics to a rehearsal studio that has original 30+ year-old vintage Neumann U87 microphones and did a few A/B tests to see how I did on my first microphone build.
The results had me grinning for days. Not only was the output level of my microphones identical to the actual vintage U87, they sounded almost exactly the same. I say almost, because there was a slight difference that was clearly due to the stiffness on my new capsules. A bit of aging would soften the capsules up enough to make them move more easily. So after that test I set th