Quick Answer / Summary: Five steps: measure the route with a string and add 40 cm, cut one continuous length, strip 10-12 mm at each end without nicking copper, terminate with the plug your terminals accept, then test continuity and polarity with a meter before installing. Label both ends. A lead made this way outlives the furniture it runs behind.
An amplifier lead is one complete run – amplifier terminal to speaker terminal – and making a good one is a five-step job that takes ten minutes. The steps are measuring, cutting, stripping, terminating, and testing; skipping the last one is how intermittent channels are born.
Measuring and Cutting
Use a string along the actual route, then lay the string straight and measure it. Add 20 cm at each end for service loops and re-termination. Cut with sharp side cutters so the jacket does not tear; a ragged cut invites the jacket to split later along the conductor. One continuous length per lead, always – a joint is a future fault.
Stripping Without Damage
Set the stripper to the jacket diameter, not to a guessed depth. Score lightly, flex, and pull the jacket free – the copper should be bright and unmarked. A nick in a strand is a stress riser; with fine strands, several nicks mean the end should be cut back and stripped again.
Tinning or Not
Tinning bare copper with solder can help in screw terminals that crush strands, but it stiffens the end and can loosen under pressure over time. For spring clips and binding posts, twisted bare copper is the better choice; for spade and pin terminations, follow the connector’s own instruction.
Terminating and Testing
Terminate to match the terminal family: bare for clips and posts, banana for frequent changes, spades under collars. Then test before installation – a multimeter’s continuity mode across each conductor end to end, and a resistance reading that should be a fraction of an ohm for a domestic run. Check that no strand bridges the two conductors at either end; that check alone prevents most protection trips.
The Polarity Confirmation
With the lead disconnected, confirm which conductor carries the stripe from end to end using continuity. Mark both ends – red tape on the marked conductor – so the amplifier and speaker see the same convention. Two minutes here saves an evening of chasing cancelled bass.
Installing Without Strain
Route the lead without tight bends at the plug, secure it so its weight does not hang from the terminal, and leave the service loop where it can be reached. A lead that pulls on its plug will fail at the plug, not in the middle.
A Lead That Outlives the Furniture
The lead’s life is decided at its ends: strain relief that takes the pull, service loops that allow re-termination, and labels that survive. A lead built with those three habits is still in service when the cabinet it runs behind has been replaced twice.
Lead-Making Steps
| Step | Specification | Failure If Skipped |
|---|---|---|
| Measure | String along route + 40 cm | Lead too short |
| Cut | One continuous length | Joint becomes a fault |
| Strip | 10-12 mm, no nicks | Broken strands, weak end |
| Terminate | Match terminal family | Loose or bridging connection |
| Test | Continuity and polarity | Intermittent channel, phase error |
Practical Applications
Making a single replacement lead for a workshop system, building matched pairs for a listening room, re-terminating inherited cable after a move, and teaching a first-time installer the five-step method.
Frequently Asked Questions
How long should a single amplifier lead be?
The measured route plus about 40 cm total for service loops at both ends. Longer than needed adds resistance without benefit; shorter cannot be fixed without a joint.
Should I tin the wire before terminating?
Only where a screw terminal crushes fine strands. For spring clips and binding posts, twisted bare copper makes better contact; follow the connector manufacturer’s instruction for spades and pins.
How do I test a lead before installing it?
Use a multimeter’s continuity mode end to end on each conductor, confirm the stripe’s path, and check that no strand bridges the two conductors. A resistance reading near zero confirms a sound lead.