The existing electronics are modified to suit the capsule and to eliminate background hiss. This requires a small NPO ceramic or mica capacitor of 20 to 30 pF, an electrolytic capacitor of 250 to 1000 mF at 16V or more, (Make sure it’s small enough to fit inside the mic.) and optionally but recommended, a 270 to 470 ohm, 1/8 watt or higher, resistor.

Soldering is required. If you aren’t experienced with a soldering iron, enlist a friend who is. The capacitors attach to existing pads on the printed circuit. The optional resistor requires cutting a trace and soldering. None of the parts are critical values, anything close from your parts stash should work. I used 22pF, 1000mF / 16V, and 330 ohms 1/4 watt.

So let’s get to it! First task is to mount the new capsule. We have to cut the small capsule holder.

The new capsule is glued to the holder with urethane or epoxy glue. Set it aside for the glue to dry while we work on the electronics.

Your electronics should look like this, universal in cheap Chinese mics:

Notice these two pads. The small ceramic cap connects here

The large electrolytic filter cap + connects to this pad and -- to ground.

The new capsule connects to the existing wires.

The optional resistor will reduce low frequency noise from the voltage regulator. This is trickier to solder than the capacitors.

Skip it if you’re new to soldering. Cut the trace here and scrape off the green solder mask. Solder the resistor across the cut trace.

Finished printed circuit, both sides.

The last change is to swap the wires at the output going to pin 2 & 3 of the XLR connector. All of these mics I’ve looked at have phase reversed from studio standard. Check your mics.

A finished pair of modified BM-800s next to a couple of more familiar mics.

These sound like other mics using this capsule, like Alex and Homero’s “Alice” mics, but without scratch-built electronics.

Solder the ceramic cap here.