I recently bought three cartridges and head shells for just £3. While I will probably use the head shells, the cartridges are not going to be allowed near a decent record. Let’s take one apart and see what’s inside.
The Stylus are already missing, so the first stage is to separate the cartridge from mounting bracket. The two are just clipped together. Careful manipulation with a screwdriver ensured separation.
The cartridge proper is encased in a metal surround to keep out electromagnetic interference. Again a small screwdriver was the tool of choice to prise the surround open and slip it off the cartridge.
We can now see the coils, but they are protected by some easily removed transparent tape.
The plastic chassis for the cartridge is a wrap around design. Once I found where the clip was, it unfurled to reveal a pair of coils and their connections to the pins on the back.
Removing the coils took a bit of pushing and shoving. They are just a friction fit into the chassis. The metal you see here is all ferrous. It is difficult to see from the pictures, but they actually form two horse shoe magnetic circuits. These are arranged at 90 degrees to each other. With a stylus attached, its magnet sits in the middle of this arrangement and affects both coils. The 90 degree displacement is what make one pick up left channel and the other right.
So these are the component parts that go to make an MM cartridge. It’s all quite straightforward really. The complex high tech bit is the stylus, which is not included in the above investigation.