Crestron electronic DMTH4 Hardware Installation, Installing the DM system into a rack, Cables

Installation Guide

Hardware Installation

Installing the DM system into a rack

The DMTH4 occupies a single space. There are no special ventilation requirements. Mount with 4 rack screws using the appropriate mounting holes. It is recommended to use nylon washers to prevent damage to the front panel’s finish when tightening the screws.

For North American installations, connect the Power Cable supplied with the unit between the DMTH4 and a stable power source. All DM processors have internal switching power supplies that can tolerate voltages ranging from 100 VAC to 240 VAC. Use an approved power cable for installations outside North America.

Cables

It is recommented to use lacing bars for cable strain relief when mounting in a rack. Use only professional audio cable with proper shielding - typically, two con- ductor plus ground/shield.

Audio Connections

The analog audio inputs and outputs are connected through 5 pin de-pluggable connectors. Strip the insulation back 1/8 to 3/16" but do not tin (apply solder to) the leads. Insert the wire into a de-pluggable connector, leaving less than 1 mm of bare wire ex- posed, then tighten the retaining screw.

Caution: Do not over tighten the retaining screw.

Retaining Screw

(Do not overtighten)

5-pin depluggable

connector

Do not leave more than 1 mm of exposed wire beyond the connector.

Do not apply

solder to leads

Audio Inputs (AUX and CODEC)

Unbalanced Sources

Unbalanced audio sources (positive and ground) include items such as consumer VCR’s, DVD players, etc., and may use both two wire and three wire cables. In either case, the positive output from the source should be connected to the appropriate positive (+) input on the DMTH4. The shield or negative (–) output should be connected the DM’s negative (–) input. Two wire cables should have a jumper between the DMTH4 negative input and ground. Three wire cables should have the shield connected to the DMTH4’s ground input and the shield and negative (–) leads joined together at the unbalanced source end.

Source DM In

+	+
Shield	-

Unbalanced source to DM input

(3-Wire)

Source DM In

+	+
Shield	-

Unbalanced source to DM input

(2-Wire)

Balanced Sources

Balanced differential sources from external equipment and microphones should be wired according to Bal- anced source to DM input (3-Wire). (See illustration.) When connecting balanced sources to the DMTH4, it is important to not connect chassis ground (shield) to either signal conductor.

Note the labeling on the DMTH4 Chassis for the positive and negative leads. Ground is shared between two connections (the center pin).

Note: The DM Series does not have a “pin 1 problem.” Inputs and outputs are true differential connections.

Source DM In

+		+
-	Shield	-

Balanced source to DM input

(3-Wire)

Rio Rancho, NM 7