08/27/2025
Despite looking almost identical to a Shure 300 ribbon mic, this is actually a Sony C107, a late-60s medium-diaphragm multipattern tube microphone produced in very limited numbers and rarely seen outside Japan.
While the C37a became Sony’s most famous tube mic, the C107 was their flagship, costing 30% more. It uses a CP4a power supply, similar to the C37a’s CP3b but with variable polar pattern control and different voltages for its 6DH3 tube - Sony’s proprietary version of the Telefunken AC701k. The 6DH3 is nearly impossible to source today, and even “working” ones are often noisy. When we restore these, we always replace it with a Telefunken EF732, which is quiet, affordable, and sounds excellent.
Most C107s used gold-diaphragm capsules, but this one has a double-sided nickel membrane, giving it a uniquely airy top end that works beautifully on acoustic instruments, strings, and overheads. Our sample recording in the comments below features poorly played drums (by me) and guitar amps which aren’t an ideal fit, but should give you an idea of how it sounds. We’ll try to capture a more appropriate demo someday.
Listen to the C107 and compare it to the LOMO 19a14 at the samply link in our bio. You can even download the original multitracks if you’re nerdy enough.
In the photos you’ll notice our C107 is powered by a modified CP3b PSU. That’s because our pair arrived with no supplies or cables, so we retrofitted the CP3b with variable pattern control and correct voltages. We also had to swap in Soviet multipin connectors since the original proprietary ones are unobtainable. Needless to say, it was a pain in the ass.
