> ## Documentation Index
> Fetch the complete documentation index at: https://docs.solidyne.ar/llms.txt
> Use this file to discover all available pages before exploring further.

# Cables and connections

> Overview of audio and network cabling

## Analog Audio Connections

### XLR Inputs and Outputs

The 542APC features:

* Balanced analog **inputs** (XLR connector, transformerless).
* Balanced analog stereo **outputs** (XLR connector).

Connection follows professional audio standards.

| **Connection Type**   | **Pin 1**           | **Pin 2**      | **Pin 3**              |
| --------------------- | ------------------- | -------------- | ---------------------- |
| **Balanced Input**    | Ground              | Positive phase | Negative phase         |
| **Unbalanced Input**  | Ground (join 1 & 3) | Positive phase | Tied to pin 1 at input |
| **Unbalanced Output** | Ground              | Positive phase | No connection          |

<Warning>
  Maintain correct **phase** in balanced connections.
</Warning>

<Note>
  Use two-conductor shielded cable, preferably with **double shielding**.\
  Keep cable lengths under **30 meters**.\
  In special cases, it can be extended up to **100 meters**, accepting slight high-frequency loss.
</Note>

### RJ45 Inputs and Outputs

With the adoption of **Audio over IP (AoIP)**, various manufacturers use **RJ45** connectors and shielded multipair cable to standardize analog audio wiring.

* One RJ45 connector carries **two balanced lines**, reducing equipment size and connector count.
* Using **structured cable (STP CAT5)** for long distances simplifies installation and avoids soldering.
* At the cable end, connection to devices may require standard audio connectors.\
  For this, **Solidyne provides RJ45-female → balanced connector adapters**.

<Info>
  Solidyne devices are compatible with **StudioHub®** accessories widely used in broadcasting. More info: [www.studiohub.com](http://www.studiohub.com)
</Info>

<Tip>
  [Pin diagrams and adapter cables for cable assembly](/en/diagramas/RJ45-pinout).
</Tip>

***

## Digital Audio Connections

### AES-3 Input / Output

* When using digital input, it's advisable to also connect analog inputs.
* If signal is lost on any input, the processor automatically switches to the one with signal present.

The AES3 output is balanced and uses a **male XLR** connector.

| **Pin** | **Signal** |
| :-----: | :--------: |
|    1    |     GND    |
|    2    |  AES3 (1)  |
|    3    |  AES3 (2)  |

***

## MPX Outputs

The **542APC** features **dual MPX output** with independent level adjustment.

* MPX connectors are **BNC**.
* Use **75 Ohm coaxial cable (RG-59)**.
* Keep cable length below **25 meters**.

<Warning>
  When connecting the transmitter with MPX signal, ensure to **disable the internal pre-emphasis** of the transmitter (flat response 20 – 100 kHz). Pre-emphasis is set in the 542APC (50 or 75 µs).
</Warning>

<Info>
  Maintaining proper **ground distribution** is important.\
  If in doubt, consult Solidyne indicating the equipment and grounding scheme used.
</Info>