120 watt mixer amplifier

The Plena Mixer Amplifier is part of the Plena product range. Plena provides public address solutions for places where people gather to work, worship, trade, or relax. It is a family of system elements that are combined to create public address systems tailored for virtually any application.

The Plena product range includes:

• mixers
• preamplifiers
• power amplifiers
• a music source unit
• a digital message manager
• a feedback suppressor
• call stations
• an All-in-One system
• a voice alarm system
• a timer
• a charger
• a loop amplifier

The various elements are designed to complement each other thanks to matched acoustical, electrical and mechanical specifications.

The Plena Mixer Amplifier

The Plena Mixer Amplifier is a high performance, professional public address unit for mixing up to four separate microphone/line signals, and any one of three separate music signals. For a schematic overview of the Plena Mixer Amplifier, see figure 2.1 on the next page.

The volume of each microphone/line signal can be individually adjusted to obtain the required mix; the mixed output is controlled via the master volume control and separate high/low tone controls. The unit is easy to use, and provides a crisp call or clear music. The amplifier also has enhanced features such as ducking level control, priority, labelling, and setting indicators.

All Microphone/line inputs can be switched between microphone level and line level sensitivity. The inputs are balanced but can also be used unbalanced. Phantom power can be selected via a DIP switch to provide power to condenser microphones. Input channels 1 and 2 can take priority over all other microphone and music inputs:

• Input 1 can be activated by contact closure on a PTT (push to talk). A chime can be configured to precede an announcement.
• Input 2 can be switched automatically if a signal is available at the input, for example, if someone speaks into the microphone (VOX activation).

A telephone/70 V emergency input with VOX activation is also provided for easy integration with another PA system or a telephone paging system. It has its own volume control and overrides all other inputs, including the call station and inputs 1 and 2.

The unit also has a line output to add amplifiers for larger systems that require more output power. This output can be switched to music only, for example, so that music on hold can be provided for the telephone system.

Users can create custom labels for inputs and music sources. These labels can be attached to the special holders at the front of the mixer amplifier. Colored pins can also be inserted at various positions around the volume and tone dial controls to indicate favorite settings for a particular application.

An LED meter monitors the master output before the zone selection. This signal is also present on the headphone connector below the output meter. For total reliability and ease of use, a limiter is integrated into the output stage to restrict output if the user applies too much signal.