22 Nicolas Collins
Once removed, the disk should appear as a circle of gold or silver-colored
metal, with a smaller circle of whitish “crystal” within. Depending on the
design, there will be 2 or 3 wires connected to the disk. One will always be
connected to the metal portion, somewhere near the edge; this we will call the
“ground” connection. One will connect to the main part of the inner circle; this
we will call the “hot” connection. In some cases there will be a narrow, tongue-
like shape differentiated within the crystal, to which the third wire connects; this
we will call the “curious but unnecessary” (CBU) connection.
Cut the connecting wires so that they protrude about 2” from the disc. Strip
about 1/2” of insulation from the ends of the ground and hot wires; do not strip
the CBU wire. Tin the stripped ends.
Shielded cable consists of stranded wire inside insulation, which is then
wrapped inside a layer of braided or twisted wire, which is in turn covered by
another layer of insulation. A cross-section looks like tree rings or a target.
Shielded wire is used to protect audio signal from hum and other
electromagnetic interference. Shielded cable comes with any number of internal
conductor wires, but for audio purposes most cable has one or two internal
conductors plus the shield. Unless otherwise specified we will use cable with a
single internal conductor plus shield.
Rule #9: Use shielded cable to make all audio connections longer than 8”,
unless they go between an amplifier and a speaker.
Cut a 5’ section of shielded cable, the thinner and more flexible the better. Strip
back 1” of the outside insulation. Unbraid the shielding and twist into a single
thick strand. Now strip back 1/2” of the inner insulation, and twist the center
conductor into a neat strand. Keep the two strands separate. Tin both strands,
being careful not to melt back the insulation.