The connectors are similar to XLR but with an extra coding key and groove that allows control over the intermating of XLD plugs and XLR sockets.  Pin 1 has always been ground and/or shield if the cable is shielded, and many connectors connect it internally to the connector shell or case. With the ground connection established before the signal lines are connected, the insertion (and removal) of XLR connectors in live equipment is possible without picking up external signals (as usually happens with, for example, RCA connectors). , Seven-pin XLR connectors are used to connect some valve (tube) condenser microphones to their power supplies (carrying signal, polarisation voltage, heater and HT). XLR connectors from different manufacturers will intermate, with the exception of six-pin models, which are available in two incompatible designs. Condenser mics require a DC power supply (transmitted through an XLR cable) in order to operate the active components used and therefore, a voltage (48V, but can range from 44V to 52V) is sent down the XLR cable to power the microphone. The Australian operation was sold to Alcatel Components in 1992 and then acquired by Amphenol in 1998. https://www.buellinspections.com/testimonials/glenn-soja-leah-mitchell/. Microphones … This makes accidental contact with live parts less likely. Many other types of connectors using the XLR type shell exist, with various pin configurations.  By suitably keying connectors, analog microphones can be protected from damage by the high current digital phantom power supply provided for digital microphones. AES standards mentioned above recommend that shells of cable-mounted connectors should never be connected to pin 1 or the shield, because inadvertent contact of the shell with another grounded surface while in use can create unwanted current paths for fault current, potentially causing hum and other noise. One is the now obsolete three-pin power pattern connector manufactured by ITT Cannon. The number of pins varies. The other home inspection reports that I've seen are no comparison to your work. The word phantom is used because the power source is essentially invisible, running through the same cord that the audio signal flows through. The standard signal flow for audio in XLR connectors is that the output is a male connector and the input is female. Does your candidate home inspector use a thermal camera? However, the voltages of microphone and line level audio signals are not hazardous. Phantom power, commonly designated as +48V or P48, was designed to power microphones without using bulky external power supplies such as the ones required for tube microphones. [original research? Thanks so much. A common misnomer is that 'plugs' are free connectors[ii] and 'sockets' are panel-mounted, but XLR uses many free female sockets and panel-mounted male plugs. Hi Charles, Thank you so much for this great and very professional inspection. We felt confident that all of the negative and positive aspects of the home were brought to our attention on sight. This voltage is commonly referred to as phantom power. An alternative to battery power is phantom power, which consists of direct current applied equally through the two signal lines of a balanced audio connector, usually a three-pin XLR connector. Thank you for your outstanding work! This use is commonly seen in PA system applications and seems to be growing more common. ITT Cannon continues to manufacture XLR connectors in Japan. . The terminology for labeling the corresponding members of a pair of mating connectors follows the usual rules for the gender of connectors: a 'male' connector is the one with pins on the smallest element, 'female' has corresponding receptacles. Phantom power supplies are often built into mixing desks, microphone preamplifiers and similar equipment. The connectors are circular in design and have between three and seven pins. They had one-tenth of the information that your report supplied me for the home I was thinking about purchasing. Most modern mixers provide 48 volts, which has become so common that many people assume that phantom power automatically means 48 volts. , Three-pin XLR connectors are by far the most common style, and are an industry standard for balanced audio signals. https://www.buellinspections.com/testimonials/12807/, https://www.buellinspections.com/testimonials/bui/. The three-pin XLR connector is commonly used for DMX512, on lighting and related control equipment, particularly at the budget / DJ end of the market. However, using three-pin XLR connectors for DMX512 is specifically prohibited by section 7.1.2 of the DMX512 standard. Many mixers and recorders intended for that market have a T-power option. I have reviewed the information and will be using this to negotiate our terms with the seller. As of 2016, XLR connectors are available with up to 10 pins, and mini XLR connectors with up to eight. XLR connectors are available in male and female versions in both cable and chassis mounting designs, a total of four styles.  Use of the three-pin XLR in this context firstly presents a risk of damage to the lighting equipment should an audio cable carrying 48-volt phantom power be accidentally connected, and secondly encourages the use of cable following analogue audio specifications for DMX, which can lead to signal degradation and unreliable operation of the DMX network. A connector with the coding key installed will not mate with a connector that does not have the matching groove. An obsolete use for three-pin XLR connectors was for MIDI data on some Octave-Plateau synthesizers including the Voyetra-8. On the other hand, equipment containing active circuitry should always have pin 1 connected to the conductive enclosure of the equipment as close as possible to the point where the signal enters the enclosure. Since equipment often requires an input on a TRS phone jack or an XLR connector, Neutrik and Amphenol offer several models of combination connector that accept both XLR and 0.25-inch (6.4 mm) TS or TRS phone plugs. , Another common use is for DC power connections for professional film and video cameras and related equipment. This use was superseded in professional audio applications by the Neutrik Speakon connector. The argument centers on the radio frequency shielding provided by the shell of the connector, which may be reduced if it is left floating. Twenty-four hours later we received a detailed 84 page summary of his findings which included pictures to clarify the issues being discussed. The XLD connector is proposed by the Audio Engineering Society AES42 digital microphone interface standard. The older Switchcraft six-pin design adds a center pin to the standard five-pin design, whereas the newer Neutrik design is a different pattern. The other reports pointed out problems, but said little more than "you should have a professional evaluate this." Two pins are used for the mono headphone signal and two pins for the unbalanced microphone signal. One complication with phantom power is that there are multiple standards for voltage levels. Often, two-conductor loudspeaker cable had three-pin female connectors on both ends, to distinguish it from a three-conductor shielded signal-level cable, which has a female connector at one end and a male at the other. How this works is that when you have ungrounded wiring, like Knob & Tube wiring or older ungrounded romex-type wiring in your home and you add metallic pathways (wires and conduit) to these old circuits the metal wires and/or conduit will pick up an induced voltage … I feel so much more confident going into this purchase knowing exactly what's going on. . , Six-pin XLR connectors are used for dual channel intercom systems and stage lighting control applications.