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One of Tweak's jungles of cables, in fact, one of the more orderly ones. |
Putting together a home studio requires a mind
that can visualize, in a second, the signal flow of the entire studio from every
remote piece though interfaces, patch bays, mixers, your computer and then the
seemingly thousands of virtual cables and switches inside each computer
application. To become the master of your recording studio, whether it is
large or small, you must always know where your signal is and know how to get it
where you need it (to your recorder, most of the time). We connect
signals to pieces of gear with cables. To maintain the integrity of the
signal, we need to understand which cables to use to connect our gear.
This page is designed to answer all the cable issues a home or project studio
is likely to confront and get you past the common misunderstandings newbies
have.
The glossy ads in the trade magazines always
show gear in it's ideal pristine state, shiny, new, and never with cables
connected. Perhaps this is a psychological point, to make the prospective
buyer get a sense of how nice it would be to have this box sitting there.
In the real world, however, there are a tangle of issues for installing almost anything.
Most of these entanglements are cable related. With each piece you buy, the
living sea of cables behind tables and racks get denser and more knotty clusters
develop, making the act of even tracing a cable from origin to destination a
matter of great intricacy.
The more cables you have the harder they are to control. You think, "oh, I need a patchbay" to control them all. But the patchbay itself will generate even more cables. Then you think, I got it, I'll use cable ties. But these to have problems of making sure all the cables in the bunch have the right length, which again leads to more cables to get all the lengths even. You might refrain from getting more gear so as not to upset the fine cable job you did!
Things can get out of control quickly
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The XLR cable (3 prong) This is a common microphone cable. May also be used as a line level cable for gear that has balanced ins and outs.
These cables can go long distances,
even to another room if required.
The TRS "Tip-ring-sleeve" cable (2-conductor plus ground) This is a cable for balanced signals just like the XLR above, it just has different connectors. Note that TRS cables are typically used for mono, not stereo, signals in most studio gear. The exception being the headphone jack.
Like the XLR these cables can go long distances, even to another room if required.
The TS "Tip-sleeve" cable (2 conductor "phone jack") This cable is for unbalanced signals. These cables should be kept as short as possible. Keep them under 12 feet and away from power transformers (wall warts) or they may pick up dreaded hum and ruin your audio signal.
The RCA Cable ("home stereo" cable) Because each cable in the RCA pair (as shown below) only has 1 conductor plus ground, it is for unbalanced signals, just like the TS cable above. Keep them as short as possible.
A variation on this is the Soundcard 1/8" stereo plug to dual RCA. Its very helpful with consumer grade soundcards and some laptops. Keep them as short as possible.
The MIDI Cable (5 pin DIN cable)
Length under 50 feet is not an issue
The Soundcard Joystick to MIDI cable looks like this
The Insert Cable (TRS to mono "Y" cable). Insert jacks on mixers are not balanced. Basically, on the TRS end, it carries both the input and the output of the mixer channel with a common ground. These cables allow you to insert a device in the channel's path, like a compressor or EQ or to carry the signal to a patchbay where devices can be conveniently patched in.
Keep them as short as possible.
Insert to direct out cable. Sometimes we want to use the inserts on our mixer as a direct out and only take the signal going out of the channel and not return a signal to it (like when we want to connect a soundcard to the mixer). You can do the old trick of sticking in a TS cable halfway (to the first click) or get one of these.
The Elco Cable (56 pin connector to 16 TRS) For professional multi-track recorders
What is a Snake? A snake is a bunch of cables bundled together in one casing. This helps keep the cable jungle a little more under control by only having one thick cable to step on or trip over, rather than 8 or 16. High quality snakes for XLR cables are expensive and include a "stage box" where the mics and other instruments are connected. Multi track snakes can be found in many types from TRS to TRS, to TS to TS, RCA to TS, and TRS to TS (an insert snake). These come in varying qualities. One problem with inexpensive snakes is that one of the 8 cables may go bad and you are stuck with loose ends hanging out.
What is an XLR jack?
What is a 1/4 " Line Input
What is an RCA line input?
What is a combo jack?
Note that the combo jack allows you to connect either XLR -or- 1/4" cables. (The 1/4" connection might either be HiZ (high impedance, i.e., "instrument level" like guitar or "line level" like keyboards, tape decks, external processors, etc.)
How do I connect a Patchbay?
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More Cables: |
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Here's the standard normal procedure. Connect an insert cable in the insert jack of the mixer. The output of the Mixer goes in the bottom rear of the bay and goes out the top rear of the bay back to the Mixer. If nothing is connected to the front jacks of the patchbay, this signal will just pass through and back. To take the output of the channel from the front of the bay, you insert a cable in the bottom front jack. To patch another signal into the mixer to replace the existing signal, you patch a cable into the upper front jack.
Stereo (2 channel) digital cables
A: These are all different methods of sending
2-channel (stereo) digital audio data down a cable to another device.
Note, this is DATA, not an analog signal. The data bypasses all analog
circuitry to make the perfect clone of the original data.
AES/EBU
requires a cable with microphone (XLR) connectors. This method is used a lot with pro gear. Common lengths for
these pathways is from 3-15 feet. Can you use a Mic cable as an AES/EBU cable?
We are advised not to. If you are in a jam, video-rated cable may work.
S/PDIF: (Stands for the Sony/Phillips Digital Interface) There are two types: Coaxial and Optical. So when some says they are connecting via S/PDIF, you should then ask, Coax or Optical? Coaxial requires a cable with RCA connectors. They look just like common "home stereo" connectors.
In fact, sometimes you can get a high quality
stereo cable to work if the run is short. The limit on length is 6 meters or
19.8 feet which is fine for the home studio.
Optical is another flavor of S/PDIF and has the square connectors
called TOSLINK connectors. 
The optical format allows for very long cable runs of 15 meters (50 feet) When you buy gear you
want to make sure your digital devices follow the same standard or you will have
to
buy a converter box. You cannot run a coax into an optical jack with an
adapter, the signal needs to be converted.
The three main methods are Roland's R-BUS,
Tascam's TDIF or Alesis ADAT Optical. These are all multichannel digital data piping schemes. They differ from S/PDIF and
AES/EBU because they send
8 channels instead of two channels. R-BUS and TDIF cables
look the same; both use a 25 pin connector, just like a large serial port cable.
. ADAT "light pipe" uses TOSLINK
(optical) cables, the same cable as optical s/pdif. But, again, when
connected to ADAT i/o these carry 8 channels of digital
audio. ADAT is a wonderful thing. Get comfortable with it.
Its becoming common on audio interfaces, digital mixers and mic preamps.
TDIF
Cable
ADAT Sync.
This is a 9 pin D-sub cable that look like a small
serial cable connector. It sends MTC (MIDI Time Code) and other
synchronization signals. Note: Many devices can send and receive MTC on
MIDI cables.
Word Clock Cables. These are 75 OHM
cables (like TV cable) but have the "press and twist" BNC connector which
you may have seen on the back of older computer monitors.
If you are using two audio
interfaces word clock keeps them in sync.
Firewire
cables are increasingly being used to connect audio interfaces as well as
Camcorders and digital video equipment.
USB (Universal Serial Bus) cables connect MIDI interfaces and some audio interfaces as well.
SCSI (Small Computer Systems Interface)
Cables come in many types. Sampler by E-Mu use the "old" 50 pin
Centronic connectors. Don't confuse these with the 50 pin "half pitch"
SCSI III connectors which are smaller. Inside the computer or sampler you
will typically find 50 pin internal SCSI cables.
Other scsi devices may use the DB25 "Mac" connector which looks identical from the outside to a 25 pin serial cable. These are also called SCSI II connectors.
There are also DB68 pin SCSI III connectors. These have 68 pins and are common on SCSI hard drives and SCSI cards. So what if you have a DB50 SCSI connector on your card and need to connect a 50 pin Centronics connector? You got it, SCSI adpater City, here you come.
 Everything you wanted to know about cables but
were afraid to ask in a music store.
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Q) What is the difference between balanced and unbalanced connections?
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Q) Can you plug an unbalanced TS plug into a balanced TRS jack
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Q) Does that make the unbalanced gear balanced
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Q) How can I make my unbalanced synth Balanced? A) With a direct box, or line level shifter, the unbalanced signal is converted to a balanced signal.
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Q) Can you use an XLR to TRS cable and keep a balanced signal path?
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Q) Are "Guitar cables" the same as "instrument" cables?
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Q) Can I use an XLR Mic cable as a balanced instrument cable with TRS adapters?
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Q) Can I connect my XLR mic to my soundblaster 1/8" phone jack? A) Yes, you can make it happen with adapters, but you will defeat the balanced signal. The Mic will likely hum and sound like garbage.
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Q) Is a headphone balanced?
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Q) Can I connect my turntable to the RCA tape in jacks on my Mixer? A) No. The turntable is a very weak signal that needs a preamp and a ground.
Q) Is it wise to run two signals to a single jack on my mixer with a "Y" cable?
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Q) Ok then, Can I split the output of a device with a Y cable to go to two destinations.
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Q) Can you use a TRS to TRS cable with 1/8" (headphone) adapters and connect a stereo soundcard output to a stereo mini disc input?
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Q) Are plastic molded plugs worse than those with metal housings ?
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Q) Can I use an RCA cable as a digital s/pdif coax cable.
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Q) Can I use a DB25 serial cable as a SCSI cable?
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Q) Can you hear the difference between quality analog cables and cheap ones.
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Q) Do you think cable ties are a good idea? A) Makes things neater and might let you vacuum more often, but is also harder to rip apart when one cable goes bad or needs to move.
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Q) Is the ADAT toslink connector the same
as a s/pdif toslink connector? A) Yes. The same cable may be used too. |
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Q) OK then, is an ADAT LightPipe the same
as an ADAT cable the same as a home theater "optical" audio cable with
toslink connectors? A) Yes. All three terms refer to the same cable. That is a Fiber Optic cable with toslink connectors. ADAT cable and LightPipe mean the same thing. Note that there is also an ADAT SYNC cable which should not be confused with the above. The sync cable is used when you connect up two or more ADAT recorders. |
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Q) is there an adapter for ADAT cables that can give you 8 separate digital
outputs? A) Not inexpensively. There is no common adapter for this task. A conversion boxes exist for this task but they are quite expensive. |
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Q) Are there RBUS, TDIF and ADAT adapters
that allow you to go from one format to another? A) As above, there are no adapters for this task. However, there are conversion boxes for RBUS to ADAT and some audio interfaces can convert ADAT to TDIF and vice versa, like the MOTU 2408. |
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Q) Is it true that ADAT cannot handle
sample rates over 48kHZ? A) For 8 channel transmission, yes, but manufacturers use two methods to work around this. The ADAT lightpipe cable has a limit to much data can be transmitted through it. Audio interface makers often solve this problem by only letting you use only 4 of the 8 inputs and outputs at the 96kHz rate. The newer alternative that is appearing is to add additional ADAT ports to split the load. This are often called the "dual SMUX" protocol. |
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Q) I am thinking if I buy super high quality MIDI cables, my audio tracks will sound better, Any ideas?
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Many cable questions and answers are in the studio central forums. Search the forums Or enter the Studio accessories and Cables Forum
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Cool Links:
Soldering and making you own cables by James at www.music-in-your-ears.com
Tutorials on Cable Building and LOTS more at Shavano Music Online
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