Quick answer: A 5 pin phono cable is a lead terminated with a five pin DIN plug, a circular connector that carries two audio channels plus a common return in one shell. It is not a variant of the RCA plug, and the two cannot be mated without an adapter cable. The layout began as a two way tape connector, so a turntable typically uses only two signal pins and the common, leaving two pins idle.
5 Pin Phono Cable: The DIN Plug Behind the RCA Pair
A turntable arrives with a lead that ends in one round plug with five pins inside a metal skirt, and nothing on the shelf will take it. The obvious move is to hunt for an adapter that turns it into two RCA plugs, and the first results are usually wrong, because a five pin DIN is not a bigger RCA and no shim will make one fit the other. The pins carry the same left, right and ground that a pair of RCA plugs carries, in a layout that predates the RCA pair becoming the default on consumer gear.
Reading the Five Pins Correctly
The plug is a metal skirt with five round pins arranged in an arc, and the numbering runs clockwise when you look at the solder side rather than the mating face. That single detail causes most of the wiring mistakes, because a diagram drawn from the front reads backwards. The shell is usually the ground reference and is bonded to one of the pins, which a meter set to continuity will confirm in a second. The layout was designed for a two way link, not for a turntable. In the original tape application two pins carried signal one way, two carried it the other, and one was the common. A record deck needs only one direction, so it uses two signal pins and the common, and the remaining two are either unconnected or shorted to the shell. Which pair is live depends on the deck, so the service manual or a continuity check beats any generic chart.
Pin numbers from the solder side
The numbers are molded into the plastic, and they only make sense from behind. Looking at the pins from the front reverses the sequence, so a chart copied from a front view and a plug held in the hand disagree about pins 1 and 5. Read the molded numbers under a light, write them down, and treat any diagram that does not state its viewing direction as unconfirmed.
Finding left, right and ground with a meter
Set a multimeter to continuity and probe the shell first: the pin that beeps is the common. Then check the deck end. A lead with two RCA plugs at the far end gives the answer directly, because each RCA center pin beeps to exactly one DIN pin, and each RCA shell beeps to the common. Write the map on a label before the plugs go back in the bag.
Five Pins Against Three Conductors
A pair of RCA plugs is three conductors in total: a center pin and a shell for the left channel, a center pin and a shell for the right, with the two shells tied together at both ends. The five pin DIN carries the same three signals in one shell, plus two pins left over. That is the whole difference in electrical terms, and it explains why an adapter cable is simple: two center conductors and one common run from five pins to three plugs. What the DIN buys is mechanical. One plug instead of two, a keyed shell that cannot be inserted the wrong way, and a latch or screw ring on the versions that have one. What it costs is compatibility: the connector went out of fashion on consumer gear, the pins sit close together and are easy to bridge with solder, and the shell is often the only ground, so a loose skirt becomes a hum.
Where the Connector Still Appears
Vintage turntables from the 1960s and 1970s are the main source, especially European decks where the five pin DIN was the standard output. Tonearm leads inside those decks often use a smaller DIN variant as well, so one repair can involve two different circular connectors in the same signal path. Beyond hi-fi, the same shell appears on some DJ mixers, on older tape machines and on test gear, usually for a two way link rather than a one way one. That history matters when you buy. A cable sold as a five pin phono lead may be wired for tape use, with all five pins connected and the directions crossed, which will not work on a turntable. The listing has to say which pins go to which plug, or you are guessing. Where the wiring is undocumented, buy a bare plug and build the lead to the map you measured.
Vintage decks and tonearm leads
Decks from the DIN era often have a captive lead with a molded plug, and the plug is the part that fails first after fifty years of flexing. Replacing the plug keeps the deck original; replacing the whole lead with a modern low capacitance cable is the better sonic choice and the worse collector choice. Both are legitimate, and both need the pinout measured rather than assumed.
Mixers, tape machines and patch panels
Pro and semi pro gear used the same shell for line level links, sometimes for a stereo pair in each direction. On a mixer the five pin socket may carry a tape return and a record send at once, which means an adapter wired for a turntable will connect the wrong pins. Check what the socket is labeled before assuming it is an output.
Adapting Five Pins to RCA Without Losing Ground
The adapter is a short cable, not a rigid part. A molded shell with a socket at one end and two RCA plugs at the other is convenient but fixed in its wiring, so buy it only where the pinout is stated. The better route is a cable made to order: five pin plug at the deck end, two RCA plugs at the preamp end, two signal pins and the common chosen for that deck, and the two spare pins left unconnected. Two rules keep the result quiet. First, connect the common at both ends. A lead that lifts the shield at one end will hum on a turntable, because the ground reference has to travel with the signal pair. Second, keep the run short. The adapter adds a connector pair to a line carrying a few millivolts, and a long low level run through two plugs and a DIN shell collects noise that no shielding inside the deck can remove.
Circular and coaxial audio connectors compared
| Connector | Pins | Signal | Typical device |
|---|---|---|---|
| RCA phono pair | Two plus shell | Left and right unbalanced | Turntable to preamp |
| 5 pin DIN | Five in an arc | Two channels plus common | Vintage deck or mixer |
| 3 pin XLR | Three, one hot | One balanced channel | Pro preamp or interface |
| 3.5 mm TRS | Three on one plug | Stereo unbalanced | Portable recorder |
| Banana plug pair | One per conductor | One speaker channel | Amplifier to speaker |
Real-World Application Scenarios
A repair bench sees three versions of this job. A 1970s deck with a five pin output arrives for service and the owner wants to use a modern preamp, so the adapter is made to a measured pinout, tested for continuity at both ends, and labeled. A club install keeps two old mixers alive, and the five pin sockets on the back feed a small interface through ready made leads whose pinout was confirmed first. A collector with a tonearm that ends in a mini DIN has the lead rebuilt with the original plug and new low capacitance cable, because the connector is fine and the cable inside the arm is not. In all three the meter, not the catalog, decides the wiring.
Related Guides on This Site
The plug family itself is described in the phono plug connector reference, with dimensions and contact details on the phono connector page. For the analog pair and its ground wire, the phono cable overview covers the standard layout, and the XLR connector pinout page is the balanced comparison when a five pin shell is being replaced by three pins.
Frequently Asked Questions (FAQ)
Q: Is a 5 pin DIN the same as an RCA?
A: No. The DIN is one circular shell with five pins; the RCA is a single coaxial barrel with a center pin and a skirt, and a pair is needed for stereo. They carry the same kind of unbalanced audio, and no shim or adapter plug makes one mate with the other. The bridge is a lead with one connector at each end.
Q: Which pins carry left and right on a turntable lead?
A: It depends on the deck, and that is the honest answer. The layout came from a two way tape standard, so different makers used different pairs for playback. Measure it: the pin that beeps to the shell is the common, and on a lead with RCA plugs at the far end each RCA center pin maps to one DIN pin.
Q: Can I use a 5 pin DIN to RCA adapter on any deck?
A: Only if the adapter is wired for that deck. Ready made adapters follow one of several conventions, and the wrong one swaps channels or grounds a signal pin. Where the deck is valuable, have the lead made to a measured pinout instead of trusting a molded part with no stated wiring.
Q: Why does my DIN lead hum?
A: Usually the shell is not bonded properly, or the two shells of the RCA pair are not joined at the preamp end. At a few millivolts a loose skirt is an antenna. Check continuity from the DIN shell to both RCA shells, and check that the deck ground post is connected to the preamp chassis.
Q: Are the two spare pins used for anything?
A: On a turntable, rarely. They exist because the layout was designed to carry a signal in both directions for tape recording. Some decks use one for a chassis bond or a muting switch. Leave them unconnected in an adapter unless the service manual says otherwise, and never bridge a spare pin to a signal pin.