Analog Audio Cables – II

TYPOLOGIES OF CONNECTORS AND ANALOGICAL PROFESSIONAL CONNECTIONS:

  1. Connectors and Unbalanced Connections  (TS Jack – Jack trs)
  2. Connectors and Balanced Connections  (XLR or Canon – Jack trs)
  3. Connectors and Power Connections (Speakon)

For each type of cable, is defined commonly male connector (fig. 1), the part inserted in the input connections, and the female connector (fig. 2), the part inserted in the output connections. Generally, a good cable can be seen both by its physical resistance (cable) that from the contact surface (connector), further to other parameters which we will see later.

n.b. For conductor means the cable in which current flows, in this case the audio signal, for connector is meant the terminal part on which each carrier signal cable is connected (welded). As for connections, refers to those structures which allow the connector housing, so that, once in contact they can withdraw the circulating signal. Generally, the connections are already pre-installed in the devices by the manufacturer but you can buy them separately as to affect a replacement or upgrade hardware.

 

Connectors and Connections Unbalanced (fig. 1)

Connector jack trs                   Connector jack ts      

Fig. 1 1.jpg

The connector with double black line is the TRS and one with a single black line is the TS.

The connections to Jack are identical for both the output that for the input for which they do not have the verse.

In (fig. 2), there’s instead the connection where you can enter the Jack connector to transfer the signal to other devices such as audio mixers, pre-amps, outboard, etc. When the purchase and use of this type connector, always make sure if the model is TS or TRS because as we will have different working principles. (A connection TS would work even with a TRS connector but it would be an under sized system that would introduce more background noise, while the TRS in a TS connection would work too but only on level and unbalanced mono, because as we shall see TRS is the connection type suitable for transferring balanced signals and stereo).

Fig. 2 images

There are also combo connectors that help to insert more connections from a single connector, generally Jack and XLR (fig. 3).

Fig. 3 XLR-phone_jack_combo_connector

The Jack cable was originally Telephone Connector, because once mainly used for connection of the telephone lines in the control units, now known by the name of Jack, is the first connector – conductor created for a professional use in audio environment. As seen fall into two families (TS and TRS) according to the type of internal wiring. They have the form as shown in figure 1, the connector is often made of brass material, aluminum often galvanized, fallen into disuse the iron, less qualitative and easily oxidizable.

The tip of conducting (see figure 1 Tip), called precisely Tip (a few millimeters of the section in which circulates the audio signal), can be appeased gold (best), brass or part of the material itself (poorer), and in so as not to oxidize it and always have the best yield of the signal, because if it was all gold, in addition to cost a fortune being very resistant to the passage of the current gold, would also be a very poor connector. An unbalanced cable is generally used to transport line signals, then in the order of a few volts. An example are the links between insert audio mixer and outboard gear, or in line input connections, always in the audio mixer or outboard effects. Once the TS connection was also used for the transport of the power signal (tens of volts) then fell into disuse because of the poor reliability of the connection. Always the TS is not used instead to microphone signals (millivolts) as the unbalanced signal as we saw in Part 1 of this subject is inclined to upload interference for very long distances (a microphone connection usually runs tens of meters). In the consumer environment, instead sometimes you see the use of the TRS jack for the microphone signal transport, considering short the path that such a signal has to do, because as we will see TRS is able to transport also balanced signal that allows the travel of long lengths with minimum attenuation of the signal and introduction of noise.

In Pro environment for convenience and compatibility issues the Jack connection is almost always TRS and also is used to send and receive signals with unbalanced TS jack.

An unbalanced cable (TS or TRS) in order to work in the best conditions by loading the shortest possible interference should not be longer than 10 meters, if the route that must travel is longer than is necessary to balance the signal, for example, as we will see through the use of the D.I. Box.

It is called unbalanced connection, when it doesn’t present the circuitry for the transport of the balanced signal, present instead in those connections XLR and balanced Jack TRS. It is used mostly for the line signal transport (few volts) because, transporting signals with fairly high voltages, does not suffer from at least part of the electromagnetic interference present in the air, although it often finds with the shield for greater protections.

Being a connector with less resistance than the XLR, due to the greater section of the copper conductors, it should have an attenuation of less than equal distance. In fact, the unbalanced means that, despite the presence of the shield as a protection, in case of long distances, are loaded many interference that when amplified severely disturb the signal. As told an unbalanced connector does not travel more than 10-12 meters, and its dynamics is lower by 10-15 dB compared to the conductor balanced after about 100 meters of cable.

The TS jack (2-pole) (fig. 4)

Fig. 4 ts

T stands for tip (audio signal) and S stands for sleeve (ground).

The mass as for the other cables is a copper filament which follows the course of the cores of conduction in which circulate the audio signal and will be welded in (1 sleeve) can be found in the outer part in 1, the tip in which circulates the audio signal welded (2 tip) can be found in the outer terminal pin (2). The potential difference in the conductor is created between the tip and the mass and it is had therefore the tension that brings this type of conductor according to the standard must have nominal values of – 10 dBV (0.32 V) for consumer use and +4 dBu (1.23 v) for pro use. The Jack the TS is identified by a black line on the terminal as seen previously.

Let’s see below a block diagram (fig. 5) of the unbalanced connection, for a greater understanding (scheme of principle that applies to both microphone signals that of line, something changes only in terms of resistances and passive components immediately before the amplifier, useful for example as protections against overload and induced capacitive effects, refer to electronic books for more details):

Fig. 5 2015-12-24_13-09-23

In the unbalanced TS connection, the signal circulates along the conductor attracted by the same voltage generator of the output circuit (as for the electrical principle), in this case also it acts as an amplifier. Part of this dependent signal also returns from the various systems used (ideal 100 %), it will be taken from the input device thanks to the presence of its accumulation circuit (e.g. piloted by a transformer or amplifier), and also in this case an amplifier. The return of this signal and that is the cable that goes to close the circuit, allowing the signal to flow is the same mass.

n.b. In the mass it does not circulate the audio signal, but the connection is required to close the circuit and allow the current passes through.

If in an unbalanced system both its ts but also trs (stereo), because the functioning is very similar, if i disconnect the mass, there will be the interruption of the signal and will only perceive the background noise due to the instability of the electrons. If there are external electromagnetic interference, they will be loaded and taken all the way by compressing the dynamic and perceptible as noise listening even if the cable is specially shielded. Another problem of the unbalanced circuit, especially in environments in which the line current is not perfectly balanced leading to differences of potential different from 0 v when no signal circulates, there is a risk in the worst case overloads or otherwise strong distortions on generators and therefore also on the signal.

To overcome this problem there are constructed unbalanced circuits able to maximize the potential stability, and prevent current returns disturbing the signal generating device itself. Another method to prevent disorders, when they appear, and in relevance to listening, is to interpose along the circuit (usually before the output and input connections) a transformer device, as it does not circular the DC current or however out of a range sinusoidal of tolerance of the same transformer, exactly like that of the noise so as to eliminate the current feedback (background noise), generally coming from the mass, and, as seen cannot be disconnected.

The input connections and unbalanced output, however, are never built with transformers so-called “protective”, just because, the system would be more secure against interference but it would lose what is the quality of the signal derived from this type of connection, because the transformer introduces its own noise and has not a strong linearity in the frequency response. If you want to minimize the noise factor and interference to the present day exclusively use unbalanced connections, but where can use unbalanced connections it favors higher quality.

The unbalanced jack cable result useful in little distorted environments, so with less possible external interference and with a stable supply current, and first of all, in short routes, then not more than 10 m. In fact, on the market for this reason you can hardly buy long unbalanced cables over 10 m, wary from those long 20 m and more.

n.b. Highly professional unbalanced cables may provide a dedicated filament for the return of the signal and one exclusive for the mass.

The trs Jack (3-pole) (fig. 6)

Fig. 6 trs

(trs stands for tip, ring, sleeve)

They have a mass as that of the TS, a tip (carrying signal), and a ring (carrying signal). This connector generally serves for transporting signals stereo, having precisely two poles will pass a signal on a cable and the other on the cable signal. Sometimes it can also be used to carry balanced signals. The tension transported within this conductor is the same as the TS, then the difference of potential between the Tip and the Sleeve considering a tension for (+ 4 dBus) will be of 1,23 V, the same will also apply to the potential difference between the Ring and the Sleeve. This connector is identified by the two black lines on the terminal.

It is not used to pro level to send stereo signals with a single conductor, as that in addition to a loss of balance and therefore high background noise over 10 meters there is even a worse connection reliability compared to those XLR. Besides this, it also has a strong self-induction phenomenon with increasing distance, by circulating more signals on a same connector. Always to bring stereo signals they are not even used two TS connectors, always for the reliability and failure balancing, not two trs balanced because reliability.

The conduction points, are those that are seen in figure 6. Then there is the conduction pin seen also previously for the tip (2) only in a different welding position, the welding point (3) (the one represented in ts the tip) is the ring, and finally the mass (1).

The points of connection are specifically isolated, so as not to create interference and signal absences in the case in which the tip or the ring is in contact with the mass, because all the signal would be offloaded to the ground. In addition to this, this isolation, as will be seen, must be maintained even during the welding phase of the cables carrying signal, on the connector.

The block diagram is the same as the previous ts, only that having a single generator possesses two, one for the left and the other for the Right, the mass is common, then detaching it they lost both signals.

As mentioned can also be used to carry balanced signals, although seldom seen as professional use, it is often found as an alternative to XLR connection.

To create a balance on unbalanced trs connection (to have a balanced connection of input and output) just take advantage of one of the two poles + as a return line in which circulate the signal in opposite phase (and then look into the concept). Similarly, also a balanced cable can become unbalanced, always depends on the type of connection (will be seen later the imbalance methods of a balanced signal).

When transforming an unbalanced into balanced cable, generally they are used D.I. Box (Direct Inject Box) (we will see later their explanation), as they are active or passive transformers and real proper suitable for this purpose.

The Jack cables can have various dimensional forms, because there are connections of various sizes according to the following standards. At the professional level using connectors 1/4 inch larger than the others and with greater strength. They exist then for the consumer (for the transport of values of tension around 0,3 volts and less, and for this the conductor is generally thinner than 1/4 jack, about 11 mm with shield and 13 mm without shield) also from 1/8 inch (mini jack fig. 7) e.g. the headphone plug in CD players and smartphones, tablet and headphone output in computers and notebooks, as well as physical audio output mp3 players, made in trs to bring stereo signal, 1/10 inch (micro jack fig. 8) e.g. the headphone connector used in cell phones once ago.

Fig. 7 neutrik_ntp3rc-b_audioteka

Fig. 8 micro

Another type of connector most used at the consumer level is the mini-Jack TRRS ( Tip, Ring, Ring, Sleeve ) ( fig. 9 ), more common, but can also be found in Jack 1/4″ versions, and are connectors applied to devices that provide to handle more than one pair of signals, such as headphones with built-in microphone (Figure 10). Then are cables that can carry a stereo line (for headphones) and a microphone line at the same time (for the microphone). The mass is the Sleeve, common at all, the microphone line is connected to the circle closest to the connector base (Fig. 11).

Fig. 9 1-Pcs-New-3-5mm-1-8-Male-Plug-4-Pole-font-b-TRRS-b-font

Fig. 10 headset-stereo-professionale-cuffia-con-microfono-monacor-bh

Fig. 11 2017-05-15_00-13-06.png

There are also different jack adapters that transform the TS signal to TRS and/or TRRS, or female – female connectors (figure 12) to perform cable extensions and many other fantasies, but the best qualitative solution is always to connect devices with a single cable.

Fig. 12 nys240-connettore-mini-jack-stereo-femmina

Other connectors (fig. 13) have additional protection against the handling and avoid breakage of the conductor in the vicinity of the connector, through the metallic material or PVC sheaths springs.

Fig. 13 jack_mono

 

n.b. In some old-fashioned inputs ( where constructive standards were not yet defined ) it is possible to find mass and signal if ( ts ) or mass and two signals if ( trs ), inverted ( so be careful if the audio signal not work, this could be a problem ).

 

Circuit Breaker

There are also Jack connectors with the presence of a switching circuit of the signal trough a button, which allows to switch to the bypass signal and to extract the connector, for example, from a musical instrument without creating a potential difference such as to create “pops and distortions” on the audio signal that can lead to damage of the equipment in which this signal passes (fig. 14).

Fig. 14 2017-01-26_12-26-47.png

Generally, they provide the switching circuit only on a connector (which connector must be the one connected to the instrument in order to directly with hand deactivate and activate the circuit at will and in comfort).

This circuit is a further passive component (mass excluder) that despite transparent it introduces alterations on the passing audio band, for this they are useful connectors but definitely not of quality reference.

 

More About Analog Audio Cables:

Analog Audio Cables – I (Technical Features, Shielding, Operating Environments)

Analog Audio Cables – III (Balanced Connectors and Connections, Passive Balancing)

Analog Audio Cables – IV (Active balancing)

Analog Audio Cables – V (Differences between Jack and XLR, Bantam, Speakon, Powercon)

Analog Audio Cables – VI (RCA, MiniJack, BNC, Midi, Starquad, Edac, D-Sub, Socapex, Euroblock, Tipologie di Adattatori )

Analog Audio Cables – VII (Connection Types, Ground Loop, Solder A Cable, Acoustic Pollution)

 

Buy Analog Audio Cables from the Major Store

 

Unbalanced Audio Cable

 

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Unbalanced Audio Connectors and Connections ( Jack )

 

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Unbalanced Audio Connectors and Connections ( mini Jack )

 

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Adapters Jack and Mini Jack

 

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