The IEC connector is the standardised power inlet on the back of nearly every hi-fi component, and the markings confuse almost everyone the first time. In short: C13 is the familiar three pin socket on most gear, C15 is its high temperature sibling with a notch, C19 is the big rectangular one on serious amplifiers, and C7 is the two pin figure 8 found on small components. Each has a defined current and temperature rating, and matching the right connector to the inlet matters for safety first and sound second.
We terminate these connectors every day, so this is the plain guide we wish more manufacturers would print in their manuals.
What IEC actually means
IEC refers to the International Electrotechnical Commission, whose standard 60320 defines the small appliance couplers used worldwide. The numbering is the part that trips people up. Odd numbers name the plug on the end of the cable, the female side. Even numbers name the inlet on the equipment, the male side. So a C13 connector on your cable mates with a C14 inlet on your amplifier. When someone says their amplifier takes a C13, they mean the cable end; the socket on the chassis is a C14.
C13 and C14: the everyday standard
The C13 and C14 pair is rated at 10A and 70 degrees Celsius, and it covers the vast majority of hi-fi: integrated amplifiers, DACs, CD players, streamers and most power amplifiers of moderate output. At Australia's nominal 230V supply, 10A is roughly 2,300 watts of headroom, so the rating itself is almost never the constraint in a domestic system. What varies enormously between a moulded stock lead and a hand built one is the contact quality: how much copper is in the pins, how firmly they grip, and how the plating stands up to oxidation.
C15 and C16: the hot running variant
The C15 connector and C16 inlet carry the same 10A current rating but are certified to 120 degrees, and the inlet has a notch opposite the earth pin that a C13 cannot clear. They exist for equipment that runs genuinely hot: certain power amplifiers, some power conditioners, and any chassis where the inlet sits close to a heat source. There is also a C15A variant rated to 155 degrees, rare outside commercial gear. If your component has a notched inlet, you need a C15 on the cable, full stop. The good news is that the serious connector lines, Oyaide's rhodium plated range and Furutech's FI series, both offer the pattern, so specifying it costs you nothing in build quality.
C19 and C20: the high current pair
The C19 and C20 are the large rectangular couplers rated at 16A, found on big power amplifiers, power conditioners and distribution blocks. At 230V that is close to 3,700 watts, but the headline number undersells the real advantage: the contact area inside a C19 is far larger than a C13, so resistance at the joint is lower and the connection tolerates sustained high current without heating. On an amplifier that pulls hard at dynamic peaks, that larger, firmer interface is worth having. The Oyaide TUNAMI NIGO V2 power cable, rated 600V and 30A, is offered with C19 termination for exactly this job, and it is the combination we build most often for high current amplifiers.
C7, the figure 8
The C7 is the small two pin connector shaped like an eight, rated at just 2.5A, found on CD players, some streamers, tuners and turntable power supplies. There is no earth pin, because the equipment it serves is double insulated. Two practical notes from the bench. First, C7 cables are often treated as disposable, and the moulded versions genuinely are: thin conductors, loose fit, contacts that tarnish within a couple of years. Second, polarity matters more than people expect on a two pin connection; many listeners hear a consistent difference reversing a C7 in the socket, which is a leakage and grounding effect rather than imagination. A properly built C7 lead with real copper and a firm connector is a small, cheap upgrade that small components respond to out of proportion to its price.
Why the right rating matters
One more piece belongs in this guide, because the IEC end is only half the cable. At the wall, Australian equipment uses the AS/NZS 3112 three pin plug, and the same logic applies: a quality AU plug with plated pure copper pins and a firm cable clamp beats the moulded plug on a stock lead in every way that matters. Every cable we build is terminated at both ends to the same standard, so the connector conversation above is never undermined by a bargain plug at the wall.
Safety first, because this is mains power. A connector running beyond its temperature rating degrades its contacts, and degraded contacts heat further, which is how the cycle starts. Using a C13 in an inlet designed for C15 is not just a poor fit, it is the wrong temperature class for the equipment. Current rating is more forgiving in hi-fi, since almost nothing domestic approaches 10A at 240V, but the connector designed for the load will always run cooler and last longer.
Sound quality follows from the same physics rather than from any mystery. A connector is a joint, and every joint in the power path adds resistance. Oxidised, loosely gripping contacts add more, and they do it unevenly across the waveform peaks where an amplifier draws hardest. Rhodium plated pure copper contacts, the standard in the Oyaide and Furutech FI series bodies we fit, hold their surface for decades and grip firmly enough that the joint stops being a variable. This is why two cables built from identical wire can measure and sound different: the difference is at the ends.
Our recommendation
Check the inlet on your component before you buy anything. Notched inlet means C15, large rectangular inlet means C19, figure 8 means C7, and everything else is almost certainly C13. Then choose the best connector body your budget allows in that pattern, because the connector is where a power cable earns its keep. Every build in our power cables category is terminated to order with the pattern your equipment takes, from the Oyaide range through to Furutech FI series bodies, and connector hardware such as the Oyaide AC Power Inlet PP sits in accessories if you are upgrading a chassis inlet at the same time. If you would rather send us a photo of the back panel and have us spec the lot, the custom order form is exactly that conversation.