Bosch - LBB 1925/10, Six-Zone Plena System Pre-Amplifier for Paging and Background Music

Features

- Professional pre-amplifier for Plena public-address systems

- Designed for voice announcements and mono background music

- Audio distribution across up to six zones

- Configurable single-channel or dual-channel operation

- Simultaneous paging and music with two external amplifiers

- Two dedicated Plena call-station input channels

- Compatible with the Bosch LBB 1941/00 all-call station

- Compatible with the Bosch LBB 1946/00 six-zone call station

- Call-station loop-through connection capability

- Universal balanced microphone or line input

- Three-pin XLR microphone or line connection

- Five-pin DIN connection with all-call priority contact

- Integrated phantom power for compatible microphones

- Selectable speech filter for improved intelligibility

- Independent call-channel volume control

- Speech-optimized bass and treble controls

- Attention-chime activation through the priority contact

- Balanced XLR master output for the call channel

- Three independent background-music source inputs

- Stereo RCA music inputs converted to mono

- Front-panel background-music source selection

- Independent background-music volume control

- Music-optimized bass and treble controls

- Dedicated balanced XLR background-music output

- Music can feed the master output in single-channel mode

- Background music operates at the lowest priority level

- Front-panel music routing to selected zones

- Six individual zone-selection buttons

- Six LED zone-status indicators

- Three-state control for every zone

- Each zone can be set to off, call or background music

- Emergency or telephone input with VOX detection

- Preset emergency-input volume level

- Emergency input has highest priority in all zones

- Two contact-closure trigger inputs

- Automatic alarm or time-signal activation

- Trigger signals can be assigned to preset zones

- Multiple attention and chime tones available

- Dedicated PC audio input for automated messages

- RS-232 interface for computer control

- Compatible with the Bosch LBB 1965/00 Message Manager

- Six available system-priority levels

- Priority management for music, microphones and call stations

- Priority management for triggers and emergency signals

- Integrated relays route amplifier outputs to zones

- Six zone outputs for 100 V loudspeaker lines

- Independent priority override for every zone

- Preset priority level independent of local volume controls

- Supports three-wire priority-override systems

- Supports four-wire priority-override systems

- Voltage-free Call Active contact for external supervision

- Overload-protected 24 VDC auxiliary output

- Can power external relays without an additional supply

- Integrated 24 VDC backup-power input

- Front-panel headphone monitoring connection

- LED VU meter for audio-level monitoring

- Selectable master or input-channel monitoring

- Suitable for stand-alone or 19-inch rack installation

- Professional two-rack-unit enclosure

Specifications

- Brand: Bosch

- Model: LBB 1925/10

- Product number: F.01U.505.591

- Product range: Plena

- Product type: Public-address system pre-amplifier

- Applications: Voice paging and background music

- Number of zones: 6

- Operating modes: Single channel or dual channel

- Integrated power amplifier: No

- Number of call-station inputs: 2

- Compatible call stations: Bosch LBB 1941/00 and LBB 1946/00

- Number of universal microphone/line inputs: 1

- Microphone/line connectors: Five-pin DIN and three-pin XLR

- Microphone/line input type: Balanced

- Microphone sensitivity: 1 mV

- Line sensitivity: 200 mV

- Microphone impedance: Greater than 1 kΩ

- Line impedance: Greater than 5 kΩ

- Phantom power supply: 16 V through 1.2 kΩ

- Microphone signal-to-noise ratio: Greater than 63 dB

- Line signal-to-noise ratio: Greater than 70 dB

- Muted signal-to-noise ratio: Greater than 75 dB

- Common-mode rejection ratio: Greater than 40 dB, 50 Hz to 20 kHz

- Microphone/line headroom: Greater than 25 dB

- Speech filter: -3 dB at 315 Hz

- Speech-filter slope: 6 dB/octave high-pass

- Number of music inputs: 3

- Music-input connectors: RCA Cinch

- Music-input configuration: Stereo converted to mono

- Music-input sensitivity: 200 mV

- Music-input impedance: 22 kΩ

- Music-input signal-to-noise ratio: Greater than 70 dB

- Muted music-input signal-to-noise ratio: Greater than 75 dB

- Music-input headroom: Greater than 25 dB

- Emergency or interconnection input: 1

- Emergency-input connector: Balanced three-pin XLR

- Interconnection sensitivity: 200 mV

- Emergency sensitivity: Adjustable from 100 mV to 1 V

- Emergency-input impedance: Greater than 10 kΩ

- Emergency VOX threshold: 45 mV

- Number of trigger inputs: 2

- Trigger-input type: Contact closure

- Computer-control interface: RS-232 through DE-9

- PC audio input: RCA Cinch

- Number of system-priority levels: 6

- Number of zone outputs: 6

- Zone-output type: 100 V loudspeaker-line switching

- Master output: Balanced three-pin XLR

- Master-output nominal level: 1 V

- Master-output impedance: Less than 100 Ω

- Background-music output: Balanced three-pin XLR

- Interconnection output: Balanced three-pin XLR

- Interconnection-output nominal level: 200 mV

- Interconnection-output impedance: Less than 100 Ω

- Recording output: RCA, two mono signals

- Recording-output nominal level: 350 mV

- Recording-output impedance: Less than 1 kΩ

- Headphone output: 6.3 mm stereo jack with mono signal

- Headphone-output nominal level: 3 V

- Headphone-output impedance: Less than 100 Ω

- Overall frequency response: 50 Hz to 20 kHz, +1/-3 dB

- Distortion: Less than 0.5%

- Bass adjustment: ±10 dB at 100 Hz

- Treble adjustment: ±10 dB at 10 kHz

- Channel separation: Greater than 70 dB at 1 kHz

- Priority muting: Greater than 40 dB

- Dynamic range: 100 dB

- Auxiliary DC output: 24 V, 250 mA maximum

- Auxiliary relay contacts: 30 V, 1 A

- Mains power supply: 230/115 VAC ±15%, 50/60 Hz

- Inrush current at 230/115 V: 1.5/3 A

- Maximum power consumption: 25 VA

- Backup power supply: 24 VDC, +10%/-15%

- Maximum current at 24 VDC: 1 A

- Mains connector: IEC

- Dimensions: 100 × 430 × 270 mm

- Rack format: 19 inches, 2U

- Mounting: Stand-alone or rack-mounted

- Weight: Approximately 5 kg

- Color: Charcoal

- Operating temperature: -10 °C to +55 °C

- Storage temperature: -40 °C to +70 °C

- Relative humidity: Less than 95%

- Safety standard: EN 60065

- EMC emission standard: EN 55103-1

- EMC immunity standard: EN 55103-2

- Regional certification: CE

- Supplied components: LBB 1925/10 pre-amplifier and power cord

- Supplied accessories: 19-inch rack-mounting brackets

- Supplied documentation: Plena CD and installation instructions