Bosch F.01U.505.591 Datasheet

Communications Systems | LBB 1925/10 Plena System Pre-Amplifier

LBB 1925/10 Plena System Pre-Amplifier

The Plena system pre-amplifier is a versatile, highperformance unit with call and mono BGM (background music). It fulfills a wide variety of public address requirements at a surprisingly low cost. It can provide dual channel operation for simultaneous calls and BGM for up to six different zones, using two Plena amplifiers.

Functions

The call channel provides two inputs for the Plena call stations, LBB 1941/00 (all-call) or LBB 1946/00 (sixzone), with loop-through capability, and universal, balanced input. One is a 3-pin XLR connector for microphone or line level (selectable), and the other is a 5- pin DIN-connector with all call priority contact, which may also be used to start one of the available chime attention signals.

The microphone input has a selectable speech filter for improved intelligibility, a volume control, and bass and treble tone controls with shelving characteristics optimized for speech. The call channel is available on the balanced XLR master output.

Six-zone system pre-amplifier, with single or dual channel operation

Two input channels for call stations

Universal input for microphone/line, with speech optimized tone control

Three inputs for BGM selection and music optimized tone control

Front panel zone selection for BGM and call station zone selection for calls

PC and trigger inputs for automated calls, alarm tones and chimes to selected zones

The BGM channel provides three inputs on stereo cinchconnectors, converted to mono, with front panel selection, volume control and bass and treble tone controls with shelving characteristics optimized for music. The BGM channel has a direct output on balanced XLR for dual channel operation. It can also feed the master output, with the lowest priority, for single channel operation. Zone selector switches on the front panel control the BGM routing. An overload protected 24 VDC output provides power for driving external relays, often making an external power supply unnecessary.

An emergency/telephone input with signal level detector (VOX) and volume preset has the highest priority to all zones. Two trigger inputs (contact closure) activate alarm or time signals to pre-selected zones. Many different chime tones are available. A PC audio input with RS-232 control provides software controlled zone configuration, or automatic messaging in combination with the

LBB 1965/00 Plena Message Manager. There are six levels of priority available for BGM, microphone, call stations, trigger inputs and emergency input. A set of relays directs the amplifier output(s) to different loudspeaker groups (zone switching).

www.boschsecurity.com

2 | LBB 1925/10 Plena System Pre-Amplifier

Each zone has a tri-state control on the front panel that can turn it off, switch it to the call channel, or to the BGM channel. The all call microphone input and emergency activation override the call station selection on the call channel. Each zone has separate priority overrides with preset volume levels. This assures an appropriate message volume, independent of any local volume settings, such as for BGM. Both three wire and four wire override schemes are supported. An override also activates a voltage-free contact (call-active) available for external control and monitoring. The master output channel, or one of the input channels, can be monitored through the headphone connector and/or the

LED VU meter.

Controls and indicators Front

•LED power meter

•Power on LED

•Call active LED

•Three knobs for mic/line volume, treble, and bass levels

•Three knobs for BGM volume, treble, and bass levels

•BGM source selection knob

•Six zone-selections keys

•Six zone status LEDs

•On/off switch

Back

•EMG input volume control

•Mains voltage switch

Interconnections

Front

•Headphone jack

Back

•One (DIN or XLR) Mic/line input

•Two (DIN/DIN) call station inputs

•PC audio (cinch) input

•Priority input

•Master (XLR) output

•BGM (XLR) output

•Emergency signal input

•Two trigger inputs

•RS-232 (DE-9)

•Three (cinch) CD, tape, aux inputs

•Six 100 V speaker outputs

•24 VDC output

•24 VDC input

•Three control inputs

•Ground screw

•IEC mains socket

Certifications and Approvals

Region	Certification
Europe	CE	Declaration of Conformity

Safety	acc. to EN 60065
Immunity	acc. to EN 55103-2
Emission	acc. to EN 55103-1

Installation/Configuration Notes

LBB 1925/10 rear view

Parts Included

Quantity Component

1LBB 1925/10 PLENA System Pre-amplifier

1Power cord

1Set of 19”mounting brackets

1Plena CD

1Installation and User Instructions

Technical Specifications

Electrical

Mains power supply

Voltage	230/115VAC, ±15%, 50/60 Hz
Current inrush	230/115 VAC, 1.5/3 A
Max power consumption	25 VA
Battery power supply
Voltage	24 VDC, +10% / -15%
Current max	1 A
Performance
Frequency response	50 Hz to 20 kHz (+1 / -3 dB)
Distortion	<0.5%
Bass control	±10 dB @ 100 Hz
Treble control	±10 dB @ 10 kHz
Channel separation	>70 dB @ 1 kHz
Priority mute	>40 dB
Dynamic range	100 dB
Mic/line input	1 x
Connectors	5 pin DIN, 3 pin XLR, balanced, with
	phantom power

Sensitivity

1 mV (mic), 200 mV (line)