MIDIMIDI, short for Musical Instrument Digital Interface, is a handy communication protocol that allows musical information to pass from one device to another. To allow the free passage of such information, MIDI jacks are located on a whole host of electronic instruments. Synthesizers, drum machines, sound modules, and even some guitars have MIDI jacks. And, to connect all of these instruments, you need some MIDI cables. The MIDI connector contains five pins (male) that plug into the female MIDI jack (port) on the instrument or device.
AES/EBUAES/EBU (Audio Engineering Society/European Broadcasting Union) cables are much like S/PDIF cables (described in the next section). The AES/EBU standards require these cables to transmit two channels of data at a time. They differ from S/PDIF cables in that they consist of XLR plugs and use balanced cables. (The following figure shows what the inputs look like on the recording equipment.) AES/EBU was developed to be used with professional audio components (hence, the use of balanced cords — the kinds used in professional-level equipment).
S/PDIFS/PDIF (short for Sony/Phillips Digital Interface Format) cables consist of an unbalanced coaxial cable (one wire and a shield) and RCA plugs. (The figure above shows what the inputs look like on the machine.) These cables can also be made from fiber-optic cable and a Toslink connector. The S/PDIF format can transmit two channels of digital data at one time. S/PDIF protocols are similar to AES/EBU standards, except that S/PDIF was originally designed for the consumer market — which explains why unbalanced cords are used. In spite of being developed for the consumer market, S/PDIF connectors are found on a lot of professional recording gear, along with (or instead of) AES/EBU.
If you want to use cords that are longer than 3 to 4 feet when using an S/PDIF connector — or about 15 feet for AES/EBU connectors — your best bet is to use video or digital audio cables. Regular audio cables degrade the sound at longer distances because they can’t transmit the type of signal that digital produces without affecting the quality of the sound. If you use audio cables for longer distances, you lose some of the sound’s definition. Some people describe this sound as “grainy.”
ADAT LightpipeThe ADAT (Alesis Digital Audio Tape) Lightpipe format allows eight tracks of digital audio to be sent at once. Developed by Alesis, ADAT Lightpipe (or simply Lightpipe for short) has become a standard among digital audio products. It consists of a fiber-optic cable that uses a special connector developed by Alesis.
TDIFTDIF (Teac Digital Interface Format) is Teac’s return volley to the ADAT Lightpipe format. TDIF uses a standard computer cable with a 25-pin connector. Like the ADAT Lightpipe, TDIF cables can transmit eight channels of digital data at a time. TDIF isn’t nearly as common as ADAT Lightpipe because Alesis made its Lightpipe technology available to other companies to use for free. Alesis encouraged these companies to adopt it as a “standard” because the Alesis ADAT recorders were so common.
USBUSB, which stands for Universal Serial Bus, is a common component in nearly all modern computers. In fact, your computer probably has more than one USB port. USB connectors are directional and contain two end types:
- A Connector: This is used for a receiving device such as your PC or USB hub.
- B Connector: This is used for a sending device, such as your USB audio interface or printer.
- Standard: This size is used for computers and peripheral equipment, such as printers.
- Mini: This size is generally used for larger mobile or portable devices.
- Micro: This size is used for phones and thinner mobile devices.
Aside from having two different types of jacks and plugs, USB also has different standards. These are the ones that matter for audio recording:
- USB 1.1: This standard (the original) can handle a data rate of up to 12 Mbps (megabits per second). You’ll still find some USB 1.1 audio interfaces on the used market, but I recommend skipping them because you’ll be disappointed in their performance.
- USB 2.0: Also called High-Speed USB, this standard can handle 40 times the data flow of the earlier standard — 480 Mbps. This is the most common connection for audio interfaces and can meet most home recordists requirement.
- USB 3.x This is also referred to as SuperSpeed or SuperSpeed+ USB. This connection transfers data ten times faster than USB 2.0 and will allow you to record a full symphony without a problem (you would need an audio interface with a lot of inputs and this will cost you)
- USB C: USB-C is twice as fast as USB 3. Though it uses the same connector as Thunderbolt, it is considerably slower. It is fast enough, however, for any audio you may want to record.
FireWireDeveloped by Apple, FireWire (also known as IEEE 1394 or iLink) is a high-speed connection that is used by many audio interfaces, hard drives, digital cameras, and other devices. You won’t find FireWire ports on any new computers, but you will still find some audio interfaces with them. Luckily, all of these audio interfaces also have USB ports.
Like USB, FireWire comes in two flavors, which are described as follows:
- FireWire 400: This standard supports data transfer speeds of up to 400 Mbps. Many audio interfaces currently use FireWire 400 as a way to connect with your computer. These interfaces can handle quite a few inputs and outputs.
- FireWire 800: Yep, you guessed it — this standard can handle data transfer rates of 800 Mbps. Several FireWire 800 devices are available.
ThunderboltThunderbolt is the fastest connectivity format to date, with speeds between 20 gigabits per second (Thunderbolt 2) and 40 gigabits per second (Thunderbolt 3). Audio interface manufacturers are excited about this amazing speed, and many experts see Thunderbolt as the next format that the pros will embrace.
Unfortunately, things got confusing when Thunderbolt 2 was quickly replaced by Thunderbolt 3, just as audio interface manufacturers rolled out a variety of Thunderbolt 2 interfaces. Each has a different type of connector (see the figure below) and a different protocol, which I outline here:
- Thunderbolt 2: Thunderbolt 2 uses the mini DisplayPort and can transfer data at speeds up to 20 gigabits per second (Gbps). This was available on computers between mid-2013 and late 2015.
- Thunderbolt 3: Thunderbolt 3 employs the USB-C connector and doubles the speed of Thunderbolt 2 to 40 Gbps. You can find Thunderbolt 3 ports on computers and peripherals made after late 2015.