Bosch LBB-1938/30

Bosch LBB-1938/30 480W Power Amplifier. Line Level (XLR) and 100V Line Input.


In Stock
SKU: LBB-1938/20 Category: Tag:


Bosch LBB-1938/30 480W Power Amplifier. Line Level (XLR) and 100V Line Input for easy addition to existing 100V line system.

LEDs on the front panel of the Bosch LBB-1938/20 show the status of the amplifier: power, audio output level, and supervised functions.

This high performance unit fulfills a wide range of public address requirements at a surprisingly low cost.

There are two separate priority controlled 100 V outputs for zones that only need announcements made via the priority input, and for zones that will not get any announcements made via the priority input.

Rack mounting brackets supplied.


  • 480 watts
  • Very high audio performance power amp
  • Can be used to boost Plena Voice alarm systems with system monitoring
  • XLR and jack input with XLR and Jack loop through outputs
  • 100 volt line input. Ideal for remote location booster amps
  • 100v, 70v and 8 ohm outputs
  • 24v override relay output
  • Temperature controlled fan
  • AC and 24VDC operation
  • LED VU Meter
  • Dual inputs with priority switching
  • Temperature controlled forced front to back
  • Mains, battery back-up, and pilot tone supervision
  • TÜV certified according to IEC 60849


Voltage: 230VAC, ±10%, 50/60 Hz
Inrush current :19 A
Max power consumption: 2200 VA
Battery power supply
Voltage: 24 VDC, +20% / -10%
Current max: 30 A
Output power (rms/maximum): 480 W / 720 W
Power reduction on backup power: -1 dB
Mains power supply
Frequency response: 50 Hz to 20 kHz (+1/‑3 dB @ ‑10 dB ref. rated output)
Distortion: <1% @ rated output power, 1 kHz
S/N (flat at max volume): >90 dB
Line inputs: 2 x
Connector: 3-pin XLR, balanced
Sensitivity: 1 V
Impedance: 20 kohm
CMRR: >25 dB (50 Hz to 20 kHz)
Gain: 40 dB
100 V input: Connector Screw, unbalanced
Sensitivity: 100 V
Impedance: 330 kohm
Line loop-through output 2 x
Connector: 3-pin XLR
Nominal level: 1 V
Impedance: Direct connection to line input
Loudspeaker outputs: 3 x
Connector: Screw, floating
Direct output: 100 V, 70 V, 8 ohm
Priority only (from input 1): 100V or 70 V internally selectable
Music (non-priority) only: 100V or 70 V internally selectable

Power consumption
Mains operation
Max power: 990 W
-3dB 715 W
-6dB 510 W
Pilot tone* 110 W
Idle 25 W
24 VDC operation
Max power 32 A (770 W)
-3 dB: 26 A (625 W)
-6 dB: 18 A (430 W)
Pilot tone*: 3.8 A (91 W)
Idle: 0.7 A (17 W)
* 20 kHz -20dB with maximum loudspeaker load

Dimensions (H x W x D): 145 x 430 x 370 mm / (19″ wide, 3U high, with feet)
Weight: Approx. 25 kg
Mounting: Standalone, 19”rack
Color: Charcoal


Bosch LBB1938_20_amp