Cables/Connectors & Adaptors
Cables/Connectors & Adaptors
What is a SCART Lead?
What is a SCART Lead – and what does it do?
SCART (from Syndicat des Constructeurs d’Appareils Radiorécepteurs et Téléviseurs) is a French-originated standard and associated 21-pin connector for connecting audio-visual equipment together. It is also known as Péritel (especially in France, where the SCART word is not normally used) and Euroconnector. The SCART connector first appeared on television sets in 1977, and became compulsory on all new television sets sold in France starting from January 1980.
Motivations and applications for SCART
Before SCART came, consumer TV sets did not offer a standardized way of inputting signals other than RF antenna ones, and even antenna connectors differed between countries. Assuming other connectors even existed, devices made by different companies could have different and incompatible standards. For example, a VHS VCR could output a composite video signal through a German-originated DIN-style connector, an American-originated RCA connector, or a BNC connector.
SCART attempts to make connecting video devices together much simpler, by providing one plug that contains all the necessary signals (refer to the Pinout to the right for details), and is standard across different manufacturers. SCART makes connecting such devices very simple, because one cable can connect any two SCART-compatible devices, and the connector is designed so that you cannot insert it incorrectly. Devices with multiple SCART connectors can pass the signals unchanged when not active, which allows daisy chaining of multiple signal sources into a single TV socket. The voltage levels are quite high, around 1V, so the signals have good noise immunity.
SCART is bi-directional regarding standard composite video and analog audio. A television set will typically send the antenna audio and video signals to the SCART sockets all the time and watch for returned signals, to display and reproduce them instead. This allows “transparent” set-top boxes, without any tuner, which just “hook” and pre-process the television signals.
This feature is used for analog Pay TV like Canal Plus and was in the past used for decoding teletext. A VCR will typically have 2 SCART sockets, one connecting to the television set, and another one for the set-top box. When idle or powered off, the VCR will forward the signals from the television set to the set-top decoder and send the processed result back to the television set. When a scrambled show is recorded, the VCR will drive the set-top box from its own tuner and send the unscrambled signals to the television set for viewing or simple recording control purposes. Alternatively, the VCR could use the signals from the television set, in which case it would be inadvisable to change channels on the television set during the recording.
SCART also enables a device to command the television set to very quickly switch between signals, in order to create overlays in the image. In order to implement captioning or subtitles, a SCART set-top box does not have to process and send back a complete new video signal, which would require full decoding and re-encoding of the color information, a signal-degrading and costly process, especially given the presence of different standards in Europe. The box can instead ask the television set to stop displaying the normal signal and display a signal it generates internally for selected image areas, with pixel-level granularity. This can be driven by the use of a “transparent” color in a teletext page.
SCART allows a connected device to power on and power off a television set, more precisely: to bring it in and out of standby mode, in the same way as a remote control would do. A VCR will optimally power on when a cassette is inserted, power on the television set (or switch it to video mode) and then start playing immediately if the cassette’s write protection tab is absent. When turned off, the VCR will ask the television set to power off as well, which the set will do if it was powered on by the VCR’s request and if it remained in video mode all along.
1 SCART Socket but need 2 Connections
I have only one SCART socket. How do I make two connections?
You can use the AV2 Expander (part number 8089111). Updated to be used with the Beo4 remote control and DVD players, its inputs allow you to:
TV: make connections to the MX TV series of televisions
Decoder/STB: add a digital box or decoder
Connect non-B&O products to a 7-Pin DIN socket
How do I connect a non B&O products to my Bang & Olufsen’s 7-pin DIN socket?
There are various adapters that you can buy. Most home audio products (and non-B&O TVs) have RCA (also called phono or cinch) sockets fitted, you you just need a twin RCA to DIN cable connected from the Line Out or Tape Out sockets of the non-B&O product to the Aux or Tape socket of the B&O system for playback of sound into the B&O system.
An alternate method is to use a 5-pin-DIN to 4 RCA adapter (as pictured) if you need both recording and playback from your non-B&O device.
It is worth noting that the 5 pin DIN plugs fitted to many iPod Input Cables and RCA Input Cables will fit perfectly and work correctly in both 5 pin and 7 pin DIN sockets. The extra 2 pins in the 7 pin socket are only used to pass data between B&O products, so they are not required when non-B&O inputs are connected. The alignment of the pins is identical for both 5 and 7 pin sockets, so the 5 pin plugs are ideal for both the older (5 pin) and the newer (7 pin) input sockets.
Can I connect my MP3 player/iPod to my B&O?
The majority of Bang & Olufsen systems have circular ‘DIN’ connections on the rear/connection side of the unit. You can use a ‘Mini-Jack’ (the kind of plug you find on the end of iPod headphones) to a ‘DIN’ cable (see image).
As an alternative, on older iPods, you can bypass the volume control of the iPod. On newer iPods, iPhones and iPads, this makes no difference to the sound quality produced.
For some Bang & Olufsen systems, such as the BeoSound 4 or BeoCentre 2, you just need a ‘Male RCA’ to ‘DIN’ connection, as these two models use direct ‘RCA’ connections. Some older Beomasters (eg. Beomaster 8000) have a combination of RCA and DIN inputs, so either type of cable can be used, depending on which sockets are free on your system.
iPod cables with 5 pin DIN plugs will fit and work perfectly in both 5 pin and 7 pin DIN sockets. Newer B&O products since the late 1980’s changed to 7 pin sockets, with the extra two pins only being used for data when another B&O device is connected. Hence, these extra pins are spare when a non-B&O device such as an iPod is connected.
Which Powerlink Cable do I need?
For those speakers with a display, you need a fully wired Powerlink cable. Speakers needing this type include the Pentalabs, Beolab 3000, and Beolab 5000. These are commonly known as ‘Mk2’ and are much thicker than Mk1 or Mk3.
ICE Powered speakers such as the Beolab 3, and Beolab 9 need to use the ‘Mk3’ Powerlink cable that can be identified by a small triangle being moulded on the plastic plug end.
Other speakers can use the 4 core ‘Mk1’cable that is much thinner, Beolab 4000, Beolab 6000 and Beolab 8000 can use these cables. However, mk.3 cables are a safer option than mk.1 cables, as they work with a much wider wide range of current and older Beolab speakers, including:-
- Beolab 1
- Beolab 2 Subwoofer
- Beolab 3
- Beolab 4
- Beolab 7.1 Centre Speaker
- Beolab 7.2 Centre Speaker
- Beolab 7.4 Centre Speaker
- Beolab 7.6 Centre Speaker
- Beolab 9
- Beolab 10 Centre Speaker
- Beolab 11 Subwoofer
- Beolab 2500
- Beolab 4000
- Beolab 6000
- Beolab 6002
- Beolab 8000
- Beolab 8002
It is essential that Beolab 5 speakers use the fully wired Mark 2 speaker wires. If used with a source with a digital output such as the BeoSound 9000 or BeoCenter 2, a digital cable can also be used in conjunction with the Powerlink cable, but the Powerlink cable is required whenever a B&O source is connected, even if this has a digital output.
What do Step-Up and Step-Down Transformers do?
What is a Step Up Transformer?
A step-up transformer is one whose secondary voltage is greater than its primary voltage. This kind of transformer “steps up” the voltage applied to it. For instance, a step up transformer is needed to use a 220v product in a country with a 110v supply.
What is a Step Down Transformer?
Its the opposite of the above, and would be used to run for example a 110v product in a country with a 220v mains supply.
What ‘Rating’ Transformer do i need?
This depends entirely on the products you will be using it with. Give the electrical retailer a detailed list of all the products you will be using with it – and also their maximum outputs. From this information he/she will be able to advise the correct transformer rating needed.
A transformer converts alternating current (AC) from one voltage to another voltage. It has no moving parts and works on a magnetic induction principle; it can be designed to “step-up” or “step-down” voltage. So a step up transformer increases the voltage and a step down transformer decreases the voltage.
How does a step up transformer or step down transformer work?
A transformer is made from two or more coils of insulated wire wound around a core made of iron. When voltage is applied to one coil (frequently called the primary or input) it magnetizes the iron core, which induces a voltage in the other coil, (frequently called the secondary or output). The turns ratio of the two sets of windings determines the amount of voltage transformation.
An example of this would be: 100 turns on the primary and 50 turns on the secondary, a ratio of 2 to 1.
Transformers can be considered nothing more than a voltage ratio device.
With a step up transformer or step down transformer the voltage ratio between primary and secondary will mirror the “turns ratio” (except for single phase smaller than 1 kva which have compensated secondaries). A practical application of this 2 to 1 turns ratio would be a 480 to 240 voltage step down. Note that if the input were 440 volts then the output would be 220 volts. The ratio between input and output voltage will stay constant. Transformers should not be operated at voltages higher than the nameplate rating, but may be operated at lower voltages than rated. Because of this it is possible to do some non-standard applications using standard transformers.
Single phase transformers 1 kva and larger may also be reverse connected to step-down or step-up voltages. (Note: single phase step up or step down transformers sized less than 1 KVA should not be reverse connected because the secondary windings have additional turns to overcome a voltage drop when the load is applied. If reverse connected, the output voltage will be less than desired.)
Step up transformers and step down transformers have a long life.
The primary components for voltage transformation are the transformer’s core and coil. The insulation is placed between the turns of wire to prevent shorting to one another or to ground. This is typically comprised of mylar, nomex, kraft paper, varnish, or other materials.
As a transformer has no moving parts, it will typically have a life expectancy between 20 and 25 years.
