Tecpro 2 MS741 Master Station

Combined power supply and 2 circuit station. Optional Extender unit increases system capability to four circuit operation.

Designed to be the hub of a wired intercom system, the MS741 is based on the successful MS731 Master Station and is compatible with current and legacy Tecpro products. The new 1U format combines a re-designed front control panel offering both loudspeaker and headphone operation with two independent, full-duplex intercom circuits.

Features

• Compact 1U format
• Built-in electret microphone on the front panel
• Front panel XLR4 input for gooseneck mic or headset
• 6.35mm Jack on rear offers additional external mic input
• Feedback cancellation presets on the front panel (circuits A and B)
• Side-tone presets on the front panel (circuits A and B) for headset use
• Mic amp limiting circuit protects against distortion and overloads
• High-efficiency elliptical speaker, 2W. External speaker jack on the rear panel
• The improved power supply offers up to a maximum of 1.1 amps per circuit (A and B)
• Supports up to 22 Tecpro BP511 beltpacks per circuit
• Circuits A and B linkable
• Two rear-panel XLR3 outputs per circuit (A and B)
• Rear XLR3 socket 'Aux' Mic/Line input. Switchable 48V Phantom power is available when 'Mic' is selected
• 'Aux' program material mixes to either or both circuits A and B. Front panel 'Aux' level control
• 'Aux' signal ducks when the microphone is active. Duck level and threshold may be adjusted internally
• Dual-action electronic 'Call' buttons offer latching and non-latching modes
• DC and 20KHz 'Call' signal send and receive. Visual and audible 'Call' indication
• DC 'Call' send may be disabled via internal link
• 24KHz Remote Mic Kill generation and recognition
• 28KHz Override signal (for remote volume restoration on Tecpro LS Loudspeaker stations) selectable on any/all circuits
• 'Announce' mode for paging to external sound system directly from the Master Station's microphone
• 15-Pin D-SUB for connecting a Master Station Extender unit (supplies 2 additional independent circuits)

Both intercom circuits (A and B) can power up to 22 Tecpro BP511 beltpacks, or a mix of the various headset and loudspeaker stations. Circuits A and B may be linked to form a single 'super circuit with double the drive capacity. The operator may speak to circuit A, circuit B, or both by pressing the associated circuit select buttons. Both circuits remain independent and cannot communicate with each other (unless linked). To attract the attention of operators who have removed their headsets, all beltpacks and most loudspeaker stations are fitted with call-lights. Depressing the Call A or Call B switch triggers all call-lights on that circuit to illuminate.

A microphone or line-level auxiliary signal can be added to Circuit A or B, both or none by pressing the Aux button and toggling through the four options. This allows external sources such as program feeds, show relay or paging announcements to be mixed onto the communications circuits. The amount of auxiliary signal added is set using the 'Aux Level' control.
Each intercom circuit has its own power supply with short-circuit protection. All protection is electronic and automatic and no resetting is necessary following the removal of a fault condition. As the supplies are independent, in the event of a cable fault temporarily disabling one circuit, the other circuit will continue to operate uninterrupted. The Master Station can be operated world-wide without the need to change power supply settings.

The built-in 2-watt elliptical speaker provides intelligible monitoring of the intercom circuits while the electret microphone recessed into the front panel supplies high-quality talk-back audio. Feedback cancellation presets for circuits A and B help control howl-round when the loudspeaker and microphone are operating simultaneously.

A front panel-mounted 4-pin XLR connector allows a gooseneck microphone or headset to be plugged in. Inserting a gooseneck microphone automatically mutes the Master Station’s internal microphone. Plugging in a headset mutes both the internal microphone and the loudspeaker.

The 'Announce' facility re-routes the signal from the Master Station’s talkback microphone away from the intercom circuits to a 6-pin DIN socket on the rear of the unit. In simple systems, this signal can be fed directly to a separate audio system supplying, for example, the front-of-house PA. In more complex installations the output may be fed directly to a stage management desk for routing around the venue (closing contacts on the SM desk can be used to trigger the 'Announce' mode remotely via the input pin on the 6-pin DIN connector). Contact closure via 2 dedicated earth-free pins on the 6-pin DIN connector also occurs during 'Announce' mode and may be used to trigger other devices.

All series two Tecpro belt pack and user stations on circuit A or B can have their microphones switched off remotely from the MS741 Master Station by use of the 'Remote Mic Kill' or 'RMK' facility. This avoids the build-up of unwanted background noise caused by microphone circuits being left open unnecessarily. This feature is not compatible with Series 1 Tecpro designs that use mechanical switches. Series 2 Beltpacks are fitted with electronic switches and will respond to 'RMK'.

In 'Override' mode, a 28KHz tone is generated which will trigger any Tecpro LS Loudspeakers on a selected circuit to operate at a pre-set level, irrespective of where the volume control is currently set. This avoids important back-stage announcements being missed because the loudspeaker volume control has been turned to zero. It can also cause the speaker to mute if the pre-set level is set at zero.

If additional communication circuits are required, linking a 27-742 Master Station Extender unit to the 27-741 Master adds a further two independent circuits, C and D.

Technical Specifications