Telex MCE325 manual Program Inputs, J14 and J15, External Speaker, J27, Auxiliary Connector, J22

resistor values. These resistors would normally be installed in the cable connector, but may be placed at any point in the signal path. Recommended values are shown in X.

Program Inputs, J14 and J15

The PROGRAM A and B inputs accept line-level (0 dBu nominal), balanced audio. The program inputs are connected using ¼-inch stereo phone plugs.

Figure 2.5 Connectors J14 and J15.

SECTION	FUNCTION
Tip	Program high
Ring	Program low
Sleeve	Common

The MCE325 must be internally programmed to assign the program inputs to the intercom lines, headphones, or speaker output (see “Program Assignment”). Program volume to the headphones and speaker is controlled by the PGM VOL control on the front panel.

External Speaker, J27

The SPEAKER OUTPUT jack provides a bridging-type output for an external speaker (8 ohms minimum). The external speaker is connected using a ¼-inch phone plug.

Figure 2.6 Connector J27.

SECTION	FUNCTION
Tip	Speaker plus
Ring	Speaker minus
Sleeve	No connection

CAUTION The MCE325 provides a bridging-type speaker output. DO NOT LET EITHER SPEAKER LEAD CONTACT GROUND.

The external speaker is turned on and off by the front panel SPKR ON switch.

Auxiliary Connector, J22

Four-Wire Channel A and B Input

The four-wire channel A and channel B inputs are connected at the auxiliary connector as follows:

Table 2.6 Auxiliary connector, J22.

PIN #	FUNCTION
8	Four-wire channel A high
21	Four-wire channel A low
9	Four-wire channel B high
22	Four-wire channel B low

The four-wire inputs must be assigned, using internal programming jumpers J19 and J20, before they can be used (as previously described in “Intercom Line-Channel Configurations (DS1-DS3, J6, J7, J19 & J20).”

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