Bosch PLE-2MA120-US – Plena Series 2-Zone 120-Watt Priority Mixer Amplifier Bosch

Plena mixer amplifiers are high performance, professional public address units with modern state‑of‑the‑art features. They are easy to use, taking the complexity away from the user and putting it where it belongs, inside the equipment. Providing a crisp call or clear music is as easy as turning on the radio. The amplifier is also surprisingly affordable, without sacrificing features such as ducking, priority and flexibility.

• 6 microphone/line inputs plus 3 music source inputs
• 70 V, telephone and a call station input with priority and VOX
• 2 zones and announcement only output
• Voice‑activated emergency override
• High output power 120 and 240 Watts
• 2-tone chime built in (7 more chimes optional with call station)
• Outputs for line out, music only out and insert point
• 24 V backup power with built‑in 24 V charger
• Separate tone controls for microphones and music sources

Microphone and line inputs
All mic/line inputs can be switched between microphone level and line level sensitivity. The inputs are balanced but can be used unbalanced. Phantom power can be switched on 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 the PTT (push to talk). A 2-tone chime can be configured to precede an announcement.
• Input 2 can be switched automatically if a signal is fed to the input, i.e., if someone speaks into the microphone (VOX activation).

When one or both inputs are configured to have priority, the amount of attenuation of the RCA input can be set between ‑2 dB (little attenuation) or -∞ dB (mute). This provides a talk-over or voice-over function. Input channels 1 and 2 also feature selectable speech filters to enhance the clarity of announcements.

Music inputs
Separate music inputs are available with their own input selector and volume control. The user can choose a music source like a CD player or radio (like the PLN-DVDT), and set the level of music. You can set the desired sound for the music source separate from the mic/line inputs. So if the music needs boosted low frequencies, this does not lead to muddy sounding voices from the microphones. A truly unique feature in its class.

Personalized settings
More unique features are available such as detachable labels where the user can write the names for inputs, music sources and zones. These labels can then be mounted on the front, protected by the clear window. Another useful feature is to indicate preferred settings on the front panel by inserting colored pins at the preset levels of all knobs. You can then instruct a user to set all the controls to the silver pins to configure the system for their particular use. A second user can set all controls to the red pins for their configuration.

Tone controls
The unique tone controls provide separate control for mic/line inputs and music inputs so that the microphone signals can be specifically optimized for excellent voice reproduction. Correspondingly, the tone controls for background music provide the equalization appropriate music reproduction. In addition, the tone controls are not standard bass and treble controls. Bosch’s experience has led them to develop a tone control that can be used as a traditional tone control with high and low control, but has a powerful contour that addresses the problems found in real situations.

The tone control for the microphone and line inputs boost warmth in voices without boosting rumble and cuts rumble without loosing warmth in the low frequencies. In the higher frequencies, the tone control boosts sparkle without adding sharpness, but when cutting is first, cuts harshness and sharpness without reducing clarity.

The tone control for the music inputs boosts deep bass first without making the sound boomy, and cuts rumble without loosing warmth in the low frequencies. In the high frequencies the tone control is similar to the microphone inputs, with slightly different frequencies to suit music reproduction.

For easy integration with another PA system or a telephone paging system, a telephone / 70 V emergency input with VOX activation is provided. It has its own preset volume control and overrides all other inputs, including call station and inputs 1 and 2. The unit also has a line output to add amplifiers for larger systems, with more output power, this output can be switched to music only so that, for instance, music on hold can be provided for the telephone system. Insert (loop through) input and output connections enable external sound processing equipment, such as an equalizer or the Plena feedback suppressor, to be connected between the preamplifier and the power amplifier stages.

Power
Plena mixer amplifiers come in 120 and 240 Watt output power options. This power is directly available on 25 V and 70 V constant voltage connections and on a low impedance connection for a 4 ohm load. Moreover, the amplifiers have a separate 70 V call-only output channel for addressing areas where only priority announcements are required. The call-only output can also be used for 3-wire remote, volume control override.

Zones
The mixer amplifier has two zone outputs. The music can be switched on and off in the zones via the front panel and optional wall panel. Announcements from the PLE-2CS two-zone call station can be routed to zone 1 or zone 2, or both. Announcements from the tel/70 V input or inputs 1 and 2 are routed to both zones. Input 1 can be used for a PLE-1CS all-call call station or any other microphone or call station with a PTT contact.

Output status
An LED VU meter displays the master output level. A headphone jack, below the VU meter, provides the mixer output signal before zone selection so that it is possible to listen to the output before the signal is sent to the zone. 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.