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
Safety acc. to EN 60065
Immunity acc. to EN 55103-2
Emission acc. to EN 55103-1
Region Certification
Europe CE
Installation/configuration notes
LBB 1925/10 rear view
Parts included
Quantity Component
1 LBB 1925/10 PLENA System Pre-amplifier
1 Power cord
1 Set of 19”mounting brackets
1 Plena CD
1 Installation 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)
2 | LBB 1925/10 Plena System Pre-Amplifier
