The fast route to safety
PLENA Public Address and Voice Alarm System
PLENA voice alarm components
LBB1930/20 PLENA 120 W Power Amplifier
120 W power amplifier for the PLENA system: 70 V / 100 V and 8 ohm outputs, two line inputs with priority switching, 100 V input for slave use.
- 120 W Output
- 70 V / 100 V and 8 Ohm
- Dual Inputs Priority Switching
The fast route to safety
PLENA Public Address and Voice Alarm System
PLENA voice alarm components
LBB1930/20 PLENA 120 W Power Amplifier
120 W power amplifier for the PLENA system: 70 V / 100 V and 8 ohm outputs, two line inputs with priority switching, 100 V input for slave use.
- 120 W Output
- 70 V / 100 V and 8 Ohm
- Dual Inputs Priority Switching
BOSCH · PLENA VOICE ALARM
Bosch LBB1930/20 Front Panel
View the amplifier’s output level meter, cooling air inlet and status indicator group. Select Zoom for a closer look.
BOSCH · PLENA VOICE ALARM
Bosch LBB1930/20 Front Panel
View the amplifier’s output level meter, cooling air inlet and status indicator group. Select Zoom for a closer look.
Key specs
- 120 W output power
- 70 V / 100 V and 8 ohm outputs
- 2 line inputs, 3 loudspeaker outputs
- Dual inputs with priority switching, 100 V slave input
Bosch LBB1930/20 Technical Specifications
The Bosch LBB1930/20 is a 120 W PLENA power amplifier for public address and voice alarm systems. It supports 70 V, 100 V and 8 Ω loudspeaker loads, priority switching and automatic switchover to 24 V DC backup power.
Electrical
| Specification | Details |
|---|---|
| AC mains supply | 230 V AC ±10%, 50/60 Hz |
| Inrush current | 8 A |
| Maximum mains apparent power | 400 VA |
| Battery backup supply | 24 V DC ±15% |
| Battery supply current rating | 6 A, listed under Battery Power Supply in the datasheet |
| Backup switchover | Automatic |
Audio Performance
| Specification | Details |
|---|---|
| Rated output power | 120 W RMS |
| Maximum output power | 180 W |
| Output reduction on backup power | −1 dB |
| Frequency response | 50 Hz to 20 kHz (+1/−3 dB at −10 dB relative to rated output) |
| Distortion | <1% at rated output power, 1 kHz |
| Signal-to-noise ratio | >90 dB, flat at maximum volume |
Audio Inputs
| Specification | Details |
|---|---|
| Line inputs | 2, with priority switching |
| Line input 1 | Priority audio input |
| Line input 2 | Program audio input |
| Line input connectors | Balanced 3-pin XLR |
| Line input sensitivity | 1 V |
| Line input impedance | 20 kΩ |
| Common-mode rejection ratio | >25 dB from 50 Hz to 20 kHz |
| Gain | 40 dB |
| Dedicated 100 V input | Unbalanced screw terminals for an existing 100 V loudspeaker line |
| 100 V input sensitivity | 100 V |
| 100 V input impedance | 330 kΩ |
Audio Outputs
| Specification | Details |
|---|---|
| Line loop-through outputs | 2, one per line input |
| Loop-through connectors | Balanced 3-pin XLR |
| Loop-through nominal level | 1 V |
| Loop-through connection | Directly connected to the corresponding line input |
| Loudspeaker output types | 3 — direct, priority-only and non-priority |
| Loudspeaker output connectors | Floating screw terminals |
| Direct loudspeaker output | 70 V, 100 V or 8 Ω |
| Priority-only output | Input 1 audio, with 70 V or 100 V selected internally |
| Non-priority output | Music or program audio, with 70 V or 100 V selected internally |
Power Consumption
| Specification | Details |
|---|---|
| AC mains at maximum output | 274 W |
| AC mains at −3 dB | 193 W |
| AC mains at −6 dB | 143 W |
| AC mains with pilot tone* | 41 W |
| AC mains at idle | 18 W |
| 24 V DC at maximum output | 7.0 A (168 W) |
| 24 V DC at −3 dB | 6.0 A (144 W) |
| 24 V DC at −6 dB | 4.3 A (103 W) |
| 24 V DC with pilot tone* | 0.9 A (22 W) |
| 24 V DC at idle | 0.1 A (2.4 W) |
Controls, Monitoring & Protection
| Specification | Details |
|---|---|
| Front-panel indicators | Power and output level (−20, −6 and 0 dB), battery operation and overheat |
| Rear-panel controls | Input 1 and input 2 level controls and mains power switch |
| Control terminals | Input 1 priority and input 2 enable |
| Supervised functions | Mains presence, battery presence, pilot tone and amplifier operation |
| Fault signalling | Normally energised fail-safe relays for supervised functions |
| Protection | Overload, short circuit and overheating |
| Cooling | Temperature-controlled, forced front-to-back airflow |
Mechanical
| Specification | Details |
|---|---|
| Dimensions (H × W × D) | 100 × 430 × 270 mm, including feet |
| Rack height | 2U |
| Mounting | Tabletop or 19-inch rack |
| Weight | Approx. 10.5 kg |
| Colour | Charcoal |
Environmental
| Specification | Details |
|---|---|
| Operating temperature | −10 °C to +55 °C |
| Storage and transport temperature | −40 °C to +70 °C |
| Relative humidity | <95% |
| Fan noise | <48 dB SPL at 1 m at maximum output |
Compliance
| Specification | Details |
|---|---|
| Safety | EN 60065 |
| EMC immunity | EN 55103-2 |
| EMC emissions | EN 55103-1 |
| Voice alarm compliance listed by the manufacturer | EN 60849 |
Included Items
| Item | Quantity |
|---|---|
| Bosch LBB1930/20 power amplifier | 1 |
| Power cord | 1 |
| 19-inch rack mounting brackets | 1 set |
| Safety instructions | 1 |
| XLR cable | 1 |
Questions & answers
Know before you buy
Quick answers about the LBB1930/20, and how it compares.
What is the Bosch LBB1930/20 used for?
The LBB1930/20 is a 120 W PLENA power amplifier for public address and voice alarm systems. It drives loudspeakers for paging and background music, and its priority input lets announcements take precedence over program audio.
What loudspeakers can I use with the Bosch LBB1930/20?
It supports 70 V and 100 V distributed loudspeaker lines and has a dedicated 8 Ω output for low-impedance loudspeakers. Choose the output that matches your loudspeaker system.
Can the LBB1930/20 extend an existing 100 V PA system?
Yes. Its dedicated 100 V input takes audio from an existing 100 V loudspeaker line so the amplifier can provide additional power to loudspeakers in a remote area.
Will the LBB1930/20 keep working during a power outage?
Yes, when a compatible 24 V DC backup battery supply is connected. The amplifier switches to backup power automatically if mains power fails.
How does the LBB1930/20 compare with the LBB1935/20 and LBB1938/30?
The LBB1930/20 is rated at 120 W, the LBB1935/20 at 240 W, and the LBB1938/30 at 480 W. For a distributed loudspeaker line, compare the total speaker tap load with the amplifier’s rated output when choosing a model.
What comes with the Bosch LBB1930/20 amplifier?
Bosch lists the amplifier, a power cord, a set of 19-inch rack mounting brackets, an XLR cable and safety instructions.
Who is an authorized Bosch distributor in Pakistan, and how can I check the LBB1930/20 price?
Electronic Security Company (ESCO) is an authorized Bosch distributor in Pakistan. Use Request a Quote on the product page to confirm the current price and availability.